can you get there with TPI

grumpyvette · Jul 12, 2014

Cool Rocking Daddy said:
Good morning, Grumpy. I have come across your name and posts in various Vette forums when looking for tuned port injection information. Here's my story.....I have a 69 Camaro with a 355 (started as 10.25:1, 300 hp 350 out of '70 Nova. flat top pistons with 4 valve reliefs) 041 pocket ported heads. Comp Extreme Energy 262 cam (218-224 @ .050, .470 lift) . Edelbrock Performer, 650 Speed Demon carb. Usual headers. Extreme Automatics Stage II 200r4, 3.42 posi rear end.

I love the look of a polished TPI. I picked up a complete unit off a '88 Vette less computer. Everything I have read says that if I want to reach my goals of having this engine pull to 5300-5500 rpms on this street-only car, I need to do some improving on the TPI parts. I have scored a set of large tube AS & M runners. I plan on having hi-flow -injection port the plenum and base. He says he can port the base to flow 265-270 cfm . I also plan on putting some Dart Iron Eagle or Pro 1 180 heads on the engine. I know that I will need to burn a chip to maximize the potential of the setup and I plan on switching to MAP computer and eliminate the ninth injector.

I get annoyed when I read threads on TPI because everybody talks about how they won't support 6500+ rpms and suck for racing. I don't want to race. I want a nice cruiser that will have the gobs of torque you want on the street. Do you feel that I can reach my goals. I am figuring I can get close to 420 flywheel HP with the proportionately bigger amount of torque that the TPI motors are famous for. The guy who runs the engine shop at TPiS seems to think I can do it. Just want a second on that before I completely jump into the water.

Thank you so much for your reply.

Chet

heres a bit of advice! so many times I get called over to help in some project, only to find the problems the guys hoping I can solve could have been avoided entirely ,
if the guy whos at this point is going partially insane, had only bothered to carefully read the details or installation instructions.

many times youll see the guy ordered the wrong part number, and theres a very similar component that exactly matches the concept ,
hes currently waist deep into, only to find the component he ordered is not compatible with the rest of the parts, hes working with.
Ive seen guys order high impedance injectors that are installed on a controller designed for low impedance injectors

http://fuelinjectorclinic.com/faqs

You can measure the resistance across the two electrical terminals of the injector. If the resistance is between 1.5 and 4.0 Ohm you have low impedance injectors. If the resistance is between 8 and 16 Ohm you have high impedance injectors.

https://www.hotrod.com/articles/hrdp-1211-low-impedance-vs-high-impedance-fuel-injectors/

Low impedance (peak and hold) injectors have a resistance of between 2 and 4 ohms. High impedance(saturated) injectors have a resistance of between 10 and 14 ohms. Low impedance and high impedance injectors cannot be used interchangeably without modification of the injector drivers.

What are the differences between low impedance/peak & hold and high impedance/saturated injectors?

The older fat body style low impedance injectors (1.5 to 4.0 Ohm) used to have faster open and close times due to the type of electrical signal pattern emitted by an ECU equipped with proper P&H signal transmitters. This “Peak and Hold” injector signal typically uses a high (4 amp) initial current to open the injector, and which reduces to a lower (1 amp) current to keep the injector open until the pulse ends. Since this method put less total current into the coil, the coil heated up less and was therefore more reliable. Since the “hold” or lower current part of the signal has created a weaker magnetic field, the injector will also close more quickly.

High impedance injectors (10 to 16 Ohm) are triggered by a low (typically around 1.2 amps) constant current signal and kept open by the same constant (saturated) current for the entire cycle. Most OEM injectors today are high impedance injectors being driven by saturated injector signals from the ECU since car manufacturers are most interested in the simpler saturated signal which is more cost effective to produce when building ECU’s, especially where there is no apparent loss of drivability or performance.

https://www.summitracing.com/parts/...MIsMryyOf_3gIVjoTICh1o7wzhEAQYAiABEgKO9fD_BwE

https://www.summitracing.com/parts/...MInIGXief_3gIVy-DICh1rpgH3EAYYAiABEgJLafD_BwE

TPI Torque Specifications

Below are the torque specifications as designated by GM for Tuned Port Injection intakes. Please note that some specifications are in lb. ft., and some are in lb. in.

Manifold to Runner Bolts 25 lb. ft. Runner to Manifold Bolts 25 lb. ft.
Fuel Rail Attaching Bolts 15 lb. ft.
Throttle Body Attaching Bolts 18 lb. ft.
Throttle Position Sensor 18 lb. in.
Idle Air Control Valve 13 lb. ft.
Throttle Body Coolant Plate 27 lb. in.
Throttle Body Cover Plate 30 lb. in.
Power Brake Vacuum Fitting 108 lb. in.
Fuel Line Nuts 20 lb. ft.
Fuel Tube Bracket Bolt 25 lb. ft.
Fuel Pressure Connection 115 lb. in.
Pressure Regulator Base to Rail 44 lb. in.
Pressure Regulator Bracket 44 lb. in.
Outlet Tube to R/H Rail Retainer 44 lb. in.

http://www.hobracing.com/tech/tpi_flow.asp
TPI Intakes and runners

The following airflow tests were performed on the University of Northwestern Ohio's SuperFlow SF600 Flow Bench. All CFM values are corrected for airflow at 28 inches of water. Injector flow rates are flowed at 43.5 PSI on an injector flow bench using test fluid with same density as gasoline.

AirFlow

Stock TPI/LT1 48mm Throttle Body w/o airfoil -- 783.0 cfm

Stock TPI/LT1 48mm Throttle Body w/ airfoil -- 821.9 cfm

TPI/LT1 52mm Throttle Body w/o airfoil -- 848.9 cfm

TPI/LT1 52mm Throttle Body w/ airfoil -- 898.8 cfm

Stock 98 Camaro 3800 II Throttle Body -- 554.3 cfm

Stock TPI Bosch MAF sensor w/ screens -- 517.8 cfm

Stock TPI Bosch MAF sensor w/o screens -- 658.4 cfm

Stock 87 GN 3.8L Turbo AC MAF sensor w/ screen -- 584.2 cfm

Stock 86 2.8L AC 5-wire MAF sensor w/ screen -- 576.2 cfm

Stock 96-up AC 3100 V6 MAF sensor w/ screen -- 616.4 cfm

Stock 96-up AC 3100 V6 MAF sensor w/o screen -- 670.7 cfm

Stock 94-up LT1 MAF Sensor w/o screen -- 719.0 cfm

Stock 85-87 Firebird TPI airbox mid piece -- 499.3 cfm

Stock 4.3/5.0/5.7 2bbl TBI complete -- 574.1 cfm (dry)

Stock 4.3/5.0/5.7 2bbl TBI w/o injectors -- 584.7 cfm

Stock 3800 vin L throttle body w/ screen -- 419.1 cfm

Stock 3800 vin L throttle body w/o screen -- 444.8 cfm

4bbl MPFI Holley Throttle Body -- 1287.6 cfm

Another source sent in these flow numbers

Flow and HP ratings for Throttle-bodies:

Flow (cfm) Max. NA HP
Stock 668 300
Stock w/airfoil 710 350
52MM w/airfoil 835 400
54MM (AS&M) 900 450
58MM 1050 500

TPI Intakes and runners flow rates

Stock intake manifold with runner
Stock....................198.72 cfm
ACCEL................213.52 cfm
Extrude/ACCEL....217.11 cfm
Super Ram............220.67 cfm

the stock TPI has a hard time flowing 230cfm even with minor port work, look here
most of this info is right off the accel,holley,edelbrock, and TPIS sites, add a little math and the results become much clearer!!!

Intake....... length ....... port in -- out
Stock GM Base--- 6.375"------ 1.47"- 1.96x1.2
TPiS base------ -6.125"------ 1.75"- 2.09x1.28
Accel base----- -6.125"------ 1.75"- 2.09x1.28
Holley base------- 6” runner 2.3”- 1.9”x 1.23 (2.337 sq inches)
Runners
Stock TPI----- -- 7.250"------1.470" round(1.70 sq inchs)
SLP ----------- - 6.625"------1.600" round (2.01 sq inchs)
Accel LTR------- 6.625"------1.615" round (2.05 sq inchs)
TPiS----------- 7.625"------1.660" round (2.168 sq inchs)
Mini ram -----3.5”
LT1 ----------3”

Runners (measured individually)
Stock....................203.17 cfm
ACCEL................242.02 cfm
Extrude/ACCEL...275.83 cfm
Super Ram............289.18 cfm
Intake manifold with 3/8 inch radiused intlet.............................222.45 cfm
Holley stealth ram ………..275cfm

Stock intake manifold with runner
Stock....................198.72 cfm
ACCEL................213.52 cfm
Extrude/ACCEL....217.11 cfm
Super Ram............220.67 cfm
Holley stealth ram …..275cfm

ACCEL Hi-Flow intake manifold with 3/8 inch radiused inlet.........251.51 cfm

ACCEL Hi-Flow intake manifold with runner
Stock....................215.83 cfm
ACCEL................232.53 cfm
Extrude/ACCEL....243.21 cfm
Super Ram............240.24 cfm

Extrude-Honed ACCEL Hi-Flow intake manifold with 3/8 inch radiused inlet ...............275.83 cfm
Extrude-Honed ACCEL Hi-Flow intake manifold with ACCEL runner ..............266.94 cfm
Edelbrock Performer RPM manifold (Stock)..........286.51 cfm
Edelbrock Victor Jr. ............275.24 cfm

HOLLEY STEALTH RAM
the HOLLEY STEALTH RAM FLOWS at 275cfm out of the box, and has the potential when matched to the correct heads and cam to totally out flow most other intakes available,can easily reach 300cfm with minor port work and costs much less
Stock…………………………… 275cfm
Ported…………………………..300cfm

Runner lengths
Stock tpi manifold 8” runners 11.25”, cylinder head 6” total 25.25”
Accel super ram manifold 8” runners 7” cylinder head 6” total 21”
Holley stealth ram manifold 6.26” ” cylinder head 6” total 12.26”
Edelbrock performer RPM runners 6” ” cylinder head 6” total 12”
Edelbrock vic jr , runner length 5.5” ” ” cylinder head 6” total 11.5”

Also interesting TPI mods. Not so sure I agree with the one on bumping up the initial timing.
http://www.hobracing.com/tech/tpi_mods.asp

http://garage.grumpysperformance.com/index.php?threads/a-well-designed-c4-exhaust.786/#post-57392

Basic TPI modifications
Friday, May 23, 2014

READ THIS

increasing power is in large part the result of increasing the amount of air/fuel mix you can efficiently pack into and burn in the cylinders and the number of power strokes per second that the engine can produce in its effective power range.

intake comes with a new throttle body

Stealth TPI Induction - L98 Stroker Installation - Super Chevy Magazine

This Chevrolet L98 TPI engine has its displacement stroked to 383 cubic inches and has stealth mods installed including a new cam and an extrude honed tuned port injection system to make 458 HP - Super Chevy Magazine

www.motortrend.com

Hello, 91 corvette building a 383

Im building a 383 for my 91 Corvette, looking for info on different combination that will make this a quick street car that may see some track time.

garage.grumpysperformance.com

I CAN ASSURE YOU IGNORING AND FAILING TO READ THROUGH THE SUB LINKS IS A HUGE MISTAKE IN THIS THREAD
RELATED INFO
A couple days of
reading the linked and sub-linked info
could save you a great deal of wasted time and money
and money spent on wrong or un-necessary parts
read the links and sub links below
a day or so spent doing reading and research,
(reading links and threads)
will frequently save you thousands of dollars and weeks of wasted work.
if you want a fast dependable car you will need to either do the research required to know exactly how and why things should work, or pay someone else to do the work that has taken that time and effort.
http://garage.grumpysperformance.co...reasonable-mild-but-dependable-upgrade.12130/

viewtopic.php?f=55&t=1052&hilit=pro+flo+edelbrock

viewtopic.php?f=32&t=546&p=685&hilit=tuned+port+restrictive#p685

viewtopic.php?f=32&t=546&p=685#p685

http://www.superchevy.com/how-to/en...ethal-weapon-project-top-gun/guide-plate.html

viewtopic.php?f=55&t=431

http://garage.grumpysperformance.com/index.php?threads/tbucket-engine-project-dart-shp.3814/

http://garage.grumpysperformance.co...-1985-corvettes-cold-start-9th-injector.2861/

viewtopic.php?f=52&t=10705&p=46582&hilit=there+with+tuned#p46582

with the mods listed you could rather easily reach or slightly exceed that 420 flywheel hp level.
the key is the better heads and porting the intakes component parts...
PROVIDED you supply the fuel/air ratio and low restriction exhaust to allow the heads to breath
a low restriction exhaust and headers would also be helpful
THESE HEADS,LINKED BELOW OR SIMILAR HEADS, but obviously verify the valve train clearances and geometry , and get the quench distance in the .038-.044 range
http://www.summitracing.com/parts/drt-127122
youll really need 36 lb injectors to support 420-440 hp.failure to upgrade injectors will cause lean burn durability issues at well under 420hp level with stock injectors
a swap to a roller cam and roller rockers along with those dart heads would make the goal far easier to reach, but like most of us your probably on a tight budget, while you may get to that power level with that flat tappet cam, a bit more duration in a similar cam like this should make it easier
http://www.cranecams.com/product/cart.p ... il&p=23976
in the future you might consider upgrading to a 3.75" stroker crank assembly and a mild over bore as the extra displacement gained converting a 350 to a 383 alone easily adds 40 ft lbs and 40 hp or more to the results from the extra displacement and crank leverage both allow the engine to operate at about 400rpm-500rpm lower and still make more power, as you look thru the links and sub links below keep in mind many are 383-406 displacement and many have larger cam duration numbers and better head flow numbers

heres what DD2000 software predicts a similar build combo produce's with basically stock TPI flow rate components, and a cam similar too the one you listed and similar dart heads, with the port work the increased flow should easily get you to your goal, especially if you swapped to the upgrade crane cam, but that might also require a higher stall speed converter

of course theres options, and doing the mods listed an adding a supercharger could easily boost your results a further 30%-35%

http://www.jegs.com/webapp/wcs/stores/servlet/topcategory_10001_10002_-1

https://www.ebay.com/itm/Weiand-908...For-Use-With-144-174-Blower-Kits/400669303867

https://www.ebay.com/itm/Weiand-622...r-Small-Block-and-Big-Block-Chev/112273744933

Have one to sell? Sell now
Weiand 6221 Offset Thermostat Housing Adapter For Small Block and Big Block Chev
your problem is VERY COMMON, if the throttle body and thermostat housing has a clearance issue on some modified EFI intakes, heres the usual cure

a couple hours spent READING THRU THESE THREADS could give you more info
http://www.smartfireinjectors.com/fuelflowchart.html

if your on a very limited budget, simply, doing some port and runner porting on the stock intake, swapping to a fairly mild crane 114132 flat tappet hydraulic cam that works with the stock converter and brakes,
and a set of new lifters and some 1.6:1 roller rockers, on the intake and 1.5:1 on the exhaust would produce a rather cost effective extra 35-40 hp, in most 1985 TPI engines

https://www.summitracing.com/parts/scc-scp1027
a https://www.summitracing.com/parts/crn-114132

http://www.highperformancepontiac.com/t ... ck_engine/

grumpyvette · Jul 12, 2014

http://www.dartheads.com/products/aitdo ... le_id/103/

http://www.superchevy.com/how-to/engine ... 6sc-major/

IVE POSTED THIS LINKED INFO BEFORE BUT IT MAY BE USEFUL HERE
as the sub links contain a great deal of related info

theres a good many more dyno tested combos in this thread
viewtopic.php?f=69&t=519

http://www.superchevy.com/how-to/vemp-0607-l98-engine-induction-system/

http://xtremecarzone.com.au/STORAGE/ART ... ptions.pdf
Id also point out that cam timing matched to the exhaust scavenging has a huge effect on potential intake flow rates

I think this may help

http://www.wallaceracing.com/Calculators.htm

http://www.wallaceracing.com/runnertorquecalc.php

http://racingfeed.com/downloads/chevy_flow_data.pdf

http://www.velocity-of-sound.com/veloci ... lator3.htm

http://2.3liter.com/Calc2.htm#MinCross

viewtopic.php?f=44&t=366&p=448#p448

http://www.highperformancepontiac.com/t ... index.html

http://www.highperformancepontiac.com/t ... index.html

viewtopic.php?f=55&t=1231&p=19119&hilit=runner+flow+numbers#p19119

DON,T FORGET TO MATCH THE HEADER SCAVENGING RPM BAND TO MATCH THE INTAKE AND CAM TIMING AND ENGINE DISPLACEMENT
in a properly designed combo cam timing,and duration, intake port cross sectional area and header length and diameter will be matched to displacement, compression ratio and drive train gearing so every factor is designed to peak efficiency at near the upper 2/3rds of the intended operational rpm band, and keep the critical piston speed below the peak operational rpm range

WHAT GOES IN NEEDS TO GET DRAWN OUT
viewtopic.php?f=56&t=185

while reading thru the info below , keep in mind the combo of cylinder heads,you select,your exhaust headers,and the restriction the exhaust system behind those headers cause,your effective compression ratio, your cam timing and the design and flow limitations of the intake manifold you used all effect the results, a stock throttle body is a minimal restrictive factor compared to what the other components listed contribute in most cases

Cool Rocking Daddy · Jul 12, 2014

Fantastic!

This verifies what I figured from doing research. The exhaust is no problem as I have 1 5/8 headers going into an American Thunder 2.5 dual exhaust system. Head change will be made before tackling this TPI swap. Fuel needs will be handled by a Phantom in-tank electric pump with the proper lines. This will be next summer's project. As you said, saving and budgeting must be done to keep the better half happy.

grumpyvette · Jul 13, 2014

http://www.hotrodhandbooks.com.au/eBook ... -03-1.html
TAKE THE EFFORT TO READ THE LINKED INFO
http://garage.grumpysperformance.co...ads-tuned-intake-turbulence.12998/#post-67611

http://forum.grumpysperformance.com...1231&p=19119&hilit=runner+flow+numbers#p19119

http://garage.grumpysperformance.com/index.php?threads/recipe-for-my-91-vette.14530/

“While I’m this far….?”

I must have said this to myself daily for the past few months & I end up going deeper into my corvette engine. So I need some advice on what I should &/or perhaps not do. My vette is an 89 w/around 72k miles on her. I finally decided to pull her from close to a decade of hibernation to...

garage.grumpysperformance.com

valve clearance notches in pistons generally run in the area of 5cc-7cc
Id suggest the 24lb for a basically stock 350 TPI application

THESE LOOK STOCK (I'm using a similar 36 lb rated set in my 383 currently)
https://www.ebay.com/i/391440066276?chn=ps&dispItem=1

, if it takes you more than an hour or so to swap injectors out you need a great deal more practice
http://garage.grumpysperformance.com/index.php?threads/my-current-corvettes-383-combo.430/

THESE DON,T (I ordered these for my BBC swap)
https://fuelinjectorconnection.com/products/24lb-bosch-3-for-tpi
https://www.highflowfuel.com/i-2390...MIoLrr3KCN2gIVTbjACh2JdgspEAAYASAAEgKqbPD_BwE
https://www.texas-speed.com/p-3973-fic-80lb-bosch-injectors-for-ls-ev14-set-of-8.aspx

either choice , of these would work
keep in mind the cpu will read the sensor data and modify the injector pulse duration,
to provide the engine with the intended fuel/air ratio, and the difference in the rated size is of zero concern as long as its properly tuned.
the rated size limits the upper flow rate but has almost no effect on mid and lower rpm flow.

he following are different static compression ratios (SCR) with a 3.48" stroke and different camshaft intake closing points @ 0.050" tappet lift on Keith Black's dynamic compression ratio calculator. The calculator, starting at 8.25:1 SCR. The dynamic compression ratio (DCR) has been kept at just over 8.0:1, a figure that is acceptable for use with today's pump gas with a little cushion:

Static CR....Intake closing point @ 0.050"....Dynamic CR.
8.25........10* ABDC......8.010........................................................................................................
8.50........20............8.012........................................................................................................
8.75........27............8.022........................................................................................................
9.00........33............8.018........................................................................................................
9.25........37............8.061........................................................................................................
9.50........42............8.029........................................................................................................
9.75........46............8.016........................................................................................................
10.00.......49............8.038........................................................................................................
10.25.......52............8.043........................................................................................................
10.50.......55............8.029........................................................................................................
10.75.......57............8.069........................................................................................................
11.00.......60............8.022........................................................................................................
11.25.......62............8.038........................................................................................................
11.50.......64............8.042........................................................................................................
11.75.......66............8.035........................................................................................................
12.00.......68............8.017........................................................................................................

Chevrolets Tuned Port Fuel Injection System, or TPI as it is more commonly referred to, first appeared on production vehicles in 1985 and, since then, has been used on all Corvettes and on many specially equipped Camaros and Firebirds. GM advertising claims of up to a 20% improvement in torque, horsepower and mileage, over equivalent carbureted engines have proven conservative, if road and dyno tests caried out by the various automotive enthusiast magazines are to be relied upon. As the following table illustrates, the horsepower and torque ratings of the basic 350 cu.in. engine used in GM cars since 1980 have increased substantially, with only minor changes other than the fuel injection system. While a portion of the power improvements can be attributed to increases in compression ratio and decreases in engine friction, especially in the later engines with roller tappet camshafts, the majority is attributable to the overall efficiency of the Computer Controlled Tuned Port Electronic Fuel Injection System.

USE THE CALCULATORS to match port size to intended rpm levels... but keep in mind valve lift and port flow limitations
http://www.wallaceracing.com/runnertorquecalc.php
http://www.wallaceracing.com/ca-calc.php
http://www.wallaceracing.com/area-under-curve.php
http://www.wallaceracing.com/chokepoint.php
http://www.wallaceracing.com/header_length.php
http://www.circletrack.com/enginetech/1 ... ch_engine/
REMEMBER ALL THE TUNED PORT ENGINES IN STOCK FORM ARE RATHER PATHETIC COMPARED TO THE TRUE POTENTIAL THE BASIC LONG RUNNER OFF A CENTRAL PLENUM INTAKE DESIGN HAS A GOOD DEAL OF MERIT, BUT CHEVY DESIGNED THE INTAKE RUNNERS TO MAXIMIZE TORQUE, IN 305-350 CUBIC INCH ENGINES,
IN THE 1500RPM-4500RPM POWER RANGE WHERE 90% PLUS OF YOUR TIME IS SPENT DRIVING ON THE ROAD

I was asked what combo of parts ID use if I was going to build a tuned port intake based small block chevy engine.
well the first step would in my mind to select the currently best flowing TPI style intake which is the FIRST DESIGN,(keep in mind the basic TPI intake design is set up to maximize mid rpm range torque,with its longer ram tube intake runners, so Id build it based on a DART BLOCK,built to be a 406-to-427 displacement with 6" rods with 7/16" ARP rod bolts and an internally balanced 4340 forged crank, forged pistons and 10.5:1 compression.
http://www.summitracing.com/parts/drt-03124272
obviously increasing the displacement, from 350 cid to 406 or larger , and bumping the compression up into the 10.5:1 range and changing the roller cam timing from about 210 @.050 to the higher 235-240 @.050 duration and high mid .550-to-.600 lift range will help, but swapping too much better cylinder heads matched too a far better flowing intake than the restrictive stock TPI, and adding tuned headers , that are tuned for scavenging those cylinders, as a matched combo can DOUBLE the power and significantly increase the rpm range, and adding low friction 1.6:1 ratio roller rockers sure won,t hurt.
but to access that higher rpm range a 3.54:1-3.73:1 rear gear and a 3200 rpm stall converter are near optimal.

THIS IS THE BEST TPI STYLE INTAKE AVAILABLE

http://www.firstfuelinjection.com
THE larger 1.75" (2.45 sq inch cross sectional area)of the FIRST intake design, vs the STOCK 1.47" diameter runner cross section (1.7 sq inch cross sectional area), of the stock G.M. tpi, intake adds at least 1200 rpm to the engines potential IF properly matched to the correct components, like 42lb injectors, un-ported this runner should provide peak power in the 4500rpm-6000rpm range, while the stock TPI intake runners peak at least 1200rpm lower, near 3400rpm where they tend to start restricting flow
Id select decent flowing heads like these
http://www.airflowresearch.com/index.php?cPath=24_33
these 1.6:1 ratio roller rockers
http://www.summitracing.com/parts/cca-1605-16
a cam like this, if your goal is max peak power
http://www.summitracing.com/parts/crn-119651
a cam like this, if your goal is good driveability on the street with good power
http://www.summitracing.com/parts/crn-119661
http://www.airflowresearch.com/super-chevy-sep-2013-195cc-sbc.php
http://www.summitracing.com/search?Sort ... er%2000471
a cam like this, (crower above)if your goal is good driveability on the street with good power, but your willing to put up with some low speed driveability issues to get more power (it basically splits the difference,I tried all three and went with the smaller crane roller

a good quality 7-8 quart oil pan with windage tray
http://www.race-mart.com/Milodon-MIL-31516.html
these valve covers
http://www.proformparts.com/product-exe ... ory_id/249
a high flow water pump
and a vertex magneto ignition
Id match that with a 3.73:1 rear gear, 4l80E transmission and 3300rpm stall speed converter
Inj Flow Rate (@ 40psid) Naturally Aspirated hp (@ 0.50)
19 lb/hr 258 hp @ 85% Duty Cycle
24 lb/hr 326 hp @ 85% Duty Cycle
30 lb/hr 408 hp @ 85% Duty Cycle
32 lb/hr 435 hp @ 85% Duty Cycle
39 lb/hr 530 hp @ 85% Duty Cycle
42 lb/hr 571 hp @ 85% Duty Cycle
47 lb/hr 639 hp @ 85% Duty Cycle
60 lb/hr 816 hp @ 85% Duty Cycle
BTW To TEST an INJECTOR with a multi meter for OHMS resistance, remove the connector from the injector, push carefully in the middle of the locking clip, with your thumb, This will make the sides, and tips move OUT WARD in their connector slots allowing the tips that hold the injector into the connector to slide out of the way from the injector body, and you can then pull the sides away. WATCH the locking clip - IT can and WILL come off and get lost, if your not careful put your V.O.M. meter on OHMS and put the leads across the two connectors ON THE INJECTOR ,it should read about 11-16 OHMS in most cases, a few are designed to read up to 19 ohms, or as low as 9 ohms , BUT GENERALLY READINGS LOWER THAN 11 OHMS tends to point to a problem with the injector , The Ford motorsport injectors in the 24lb-hr flavor test a little lower (14.1-14.3 ohms) than the bosch's @ 22lbs/hr. (15.9-16.3) BUT ALL INJECTORS IN A SET SHOULD READ WITHIN ONE OHM OF EACH OTHER if its out of that range by a wide margin ITS MORE THAN LIKELY DEFECTIVE, checking the OHMS reading as a first step will frequently detect a defective injector, naturally using your trouble codes , a shop manual and a fuel pressure gauge won,t hurt and a shop scope , or engine analyzing software with a read out to your laptop computer helps and can further isolate the problem, at IDLE speeds placing a finger tip on the side of the injector will usually allow you to feel it (CLICKING) adding a couple cans of injector cleaner and about a pint of MARVEL MYSTERY OIL to a full tank of fuel can sometimes free a sticky injector that partly clogged, but don,t do it frequently as its very hard on the CATS and O2 SENSORS if done constantly

partly clogged injectors tend to reduce power and increase emissions

notice, the injector resistance is usually stated in the description

Brand: ACCEL
Product Line: ACCEL Fuel Injectors
Part Type: Fuel Injectors
Part Number: ACC-150826
Injector Advertised Flow Rate (lbs/hr): 26 lbs./hr.
Injector Advertised Flow Rate (cc/min): 269.0cc/min
Injector Impedance: 14.4 ohms
Driver Type: 12 V saturated circuit
Overall Height (in): 2.880 in.
Seat to Seat Height (in): 2.270 in.
Manifold O-Ring Outside Diameter (in): 0.573 in.
Fuel Rail O-Ring Outside Diameter (in): 0.574 in.
Outside Diameter (in): 0.943 in.
Injector Plug Style: Bosch/Amp-style
Wiring Harness Included: No
O-Rings Included: Yes
Quantity:

http://www.megamanual.com/v22manual/minj.htm

before you go starting to buy the components keep in mind theres other options, something like a 570hp/570 ft lb TPI combo could be built, but your could exceed those numbers easily with a turbo LS engine or 496-572 big block swap
if your goal is too significantly boost the power of that c4 corvettes tuned port SBC engine, taking the time too carefully read these threads will be very helpful in reaching that goal.

http://garage.grumpysperformance.com/index.php?threads/ideal-tpi-build.12203/#post-59273

http://garage.grumpysperformance.com/index.php?threads/a-well-designed-c4-exhaust.786/#post-46459

http://garage.grumpysperformance.co...ps-on-building-a-tpi-383-c4.10434/#post-43430

http://garage.grumpysperformance.co...hing-the-drive-train-to-the-engine-combo.741/

http://garage.grumpysperformance.co...-stock-tpi-engine-components.1509/#post-74581

http://garage.grumpysperformance.co...pans-that-fit-the-c4-corvette.3071/#post-8156

http://garage.grumpysperformance.co...gine-to-match-the-cam-specs.11764/#post-55651

http://garage.grumpysperformance.co...rger-intake-runners-l98-tpi.13785/#post-72541

http://garage.grumpysperformance.co...ttle-body-size-48mm-52mm-58mm.546/#post-32516

http://garage.grumpysperformance.co...ther-efi-intake-manifold-info.431/#post-32491

http://garage.grumpysperformance.com/index.php?threads/tbucket-engine-project-dart-shp.3814/

http://garage.grumpysperformance.co...rger-intake-runners-l98-tpi.13785/#post-70716

http://www.airflowresearch.com/super-chevy-sep-2013-195cc-sbc.php

http://www.airflowresearch.com/articles/SBC/75laguna/laguna.php

grumpyvette · Apr 20, 2015

I have seen a more or less consistently re-curing general problem, I see guys have coming to the shop, and its based on the fact that Id say 80% or more of the guys that own a muscle car are darn near clueless in their ability to trouble shoot, problems,verify parts or component function and tune a car.
if the engines not running correctly theres a reason, and pulling the trouble codes,or if its an older car think it thru logically, getting out a few test meters timing lights and a vacuum gauge will tend to help you find the reason. you might be amazed at the number of times adjusting valves and a tune-up or replacing a defective sensor, OR REPLACING OLD SPARK PLUG,S or leaking vacuum hoses or worn ignition parts, make a HUGE DIFFERENCE in the way a car runs
you JUST need a shop manual for YOUR YEAR CORVETTE,OR MUSCLE CAR, a vacuum GAUGE and fuel pressure gauge , a multi meter, timing light and IR temp gun and these links. and the time spent reading the links and sub links.
theres nothing difficult , it just takes a logical step by stem process of test, verify and move to the next potential issue
IF YOU HAVE THERMOSTAT TO THROTTLE BODY CLEARANCE ISSUES

buy a CHEVY SHOP MANUAL FOR YOUR YEAR CORVETTE!
you always need a base line to start from, on a TPI corvette.
a logical step by step approach and keeping accurate notes helps.
youll NEED a multi meter, a shop manual and a timing light and fuel pressure gauge at a minimum,
set and verify your ignition timing, pull trouble codes,set your tps and iac,, then check for vacuum leaks on the lines and intake,then get out your multi meter and verify all the sensors, chances are good its a defective heat sensor or defective o2 sensor, a logical step by step approach will lead you to the problem, youll be amazed at what youll learn reading links. use of a shop manual and multi meter can be very helpful

http://www.harborfreight.com/5-in-1-dig ... 98674.html
put a fuel pressure gauge on the fuel rail on the shrader valve,

a vacuum and fuel pressure gauge is useful

Ive found its a whole lot faster to use a quality IR temp gun, to locate a individual cylinder that's mis-firing as it tends to run significantly cooler than adjacent cylinders, or hotter if its a vacuum leak at times, as lean F/A mixes tend to run hotter
(Ive used this one for years)

http://www.professionalequipment.com/ex ... ermometer/
Wide temperature range from -58 to 1832Â°F (-50 to 1000Â°C)

reading the links and sub links will prove rather useful, now and even more so later
http://forum.grumpysperformance.com/viewtopic.php?f=32&t=1401

http://forum.grumpysperformance.com/viewtopic.php?f=32&t=168

viewtopic.php?f=55&t=109

http://garage.grumpysperformance.com/index.php?threads/ideal-tpi-build.12203/#post-59261

http://forum.grumpysperformance.com/viewtopic.php?f=32&t=2697

viewtopic.php?f=52&t=196&p=325&hilit=+adjusting+valves#p325

viewtopic.php?f=70&t=2798&p=41104&hilit=trouble+shooting#p41104

viewtopic.php?f=32&t=596

http://forum.grumpysperformance.com/viewtopic.php?f=32&t=596

http://forum.grumpysperformance.com/viewtopic.php?f=32&t=661

http://www.airflowresearch.com/super-chevy-sep-2013-195cc-sbc.php

http://forum.grumpysperformance.com/viewtopic.php?f=80&t=728

viewtopic.php?f=32&t=10688&p=46303&hilit=multi+shop+manual#p46303

Grumpy · Mar 17, 2016

http://www.superchevy.com/how-to/vemp-0607-l98-engine-induction-system/

http://www.superchevy.com/how-to/engines-drivetrain/sucp-0703-stealth-tpi-induction/

http://www.superchevy.com/how-to/vemp-0609-c4-l98-corvette-turbo-install/

http://www.superchevy.com/how-to/l98-horsepower-tips-trick/

http://www.superchevy.com/how-to/vemp-1010-edelbrock-pro-flo-xt-intake/

87vette81big · Mar 17, 2016

TPI Has one Big Advantage Grumpy in todays ultra fast cars.
Near 100 % Reliability daily driving.

Not the best choice for Race Wins although .

can you get there with TPI

grumpyvette

Administrator

Stealth TPI Induction - L98 Stroker Installation - Super Chevy Magazine

Hello, 91 corvette building a 383

grumpyvette

Administrator

Cool Rocking Daddy

New Member

grumpyvette

Administrator

“While I’m this far….?”

grumpyvette

Administrator

Grumpy

The Grumpy Grease Monkey mechanical engineer.

87vette81big

Guest