Hello from San Jose

C

crossfighter

Member
Hi, I was sent over here by a kind person in another forum who said the answers I seek could be found here. I am a reformed mopar guy, I've been building mopar muscle for many years, but like I told some one else recently, the slant six dusters were starting to get to me in a bad way. I would build a strong engine and smoke some clutch bands. Fix that then decimate a rear end. Fix that then bend or break something else. This time I decided to START on a good platform, a real performance car, and build on that. So, I bought an 84 corvette crossfire car about a week ago. I'd like to upgrade the car in just about every way I can. Being in California I'm somewhat limited on certain things, and the art and experience of tuning a six pack over a purple shaft with a tight LSA isn't going to help me here. So, I humbly submit, I would like to ask some one to share with me some wisdom on how to achieve my goals with this car.
1. What is the most cam I can run with this ECM? I was told a 2040 grind by Crane is the one if I can get the heads to flow and port the intake.



2. Is there a method to choosing a chip/cam combination? How do I learn what to look for and why they work together?



3. Would a cam described as being very strong for a TPI or LT1 also run well in a crossfire? Some of those grinds are described as requiring an upgraded chip, but what chip?



4. Is Renegade the only true performance intake available for crossfire? I have looked for an X-Ram and can't find one, and can't find info on who know's how to port the stock one.




5. Why won't a cat back from an 86 C4 work on an 84? is there a different cat? I would like to upgrade the exhaust but don't want the drone of flowmasters any more, however, I have never run flowmaster's behind a cat before, will the cat mellow the flowmasters out alot?


6. And finally, since the 05125 NOS systems setup for crossfire is no longer in production, is there a way I can run nitrous on this crossfire?




I know this is a long first post, but I am dying to get down to business! I am looking at some world s/r torquer heads today, and am going to get this show on the road! So, thank you in advance, every bit of information I can find on this thing will help me make it into the crossfighter it deserves to be. I am also already looking for a fuel pump upgrade and learning what to do about the idle being so inconsistant
It's not a true lope like an isky mega cam, it's like a vacuum issue or something i suspect. I will fix it.. Thank you, so much, truly. I here grumpyvette is the man to ask about all things C4.
 
Hi, I was sent over here by a kind person in another forum who said the answers I seek could be found here. I am a reformed mopar guy, I've been building mopar muscle for many years, but like I told some one else recently, the slant six dusters were starting to get to me in a bad way. I would build a strong engine and smoke some clutch bands. Fix that then decimate a rear end. Fix that then bend or break something else. This time I decided to START on a good platform, a real performance car, and build on that. So, I bought an 84 corvette crossfire car about a week ago. I'd like to upgrade the car in just about every way I can. Being in California I'm somewhat limited on certain things, and the art and experience of tuning a six pack over a purple shaft with a tight LSA isn't going to help me here. So, I humbly submit, I would like to ask some one to share with me some wisdom on how to achieve my goals with this car.
1. What is the most cam I can run with this ECM? I was told a 2040 grind by Crane is the one if I can get the heads to flow and port the intake.

the crane 114132
http://crane.carshopinc.com/product_inf ... 916/114132
is about the largest cam that will still work with an auto transmission and the stock TPI programing

but the crane 144122 is a better match to an un moded engine with an auto transmission
http://www.cranecams.com/index.php?show ... vl=2&prt=5

2. Is there a method to choosing a chip/cam combination? How do I learn what to look for and why they work together?

it takes a good deal of experience and
knowing how each change effects the combo as a whole, theres a great deal of info in these sections of the site

viewforum.php?f=52

viewtopic.php?f=32&t=1148

viewtopic.php?f=32&t=303

viewtopic.php?f=32&t=102

taking the time and effort to read thru will help you learn a great deal

3. Would a cam described as being very strong for a TPI or LT1 also run well in a crossfire? Some of those grinds are described as requiring an upgraded chip, but what chip?

most cams that work well on the LT1 and even TPI will NOT work as well on the cross fire, youll be far better off concentrating on building an engine with a better intake and heads that flow more air than trying to cam up a cross fires pitiful stock intake and heads in an effort to compensate

4. Is Renegade the only true performance intake available for crossfire? I have looked for an X-Ram and can't find one, and can't find info on who know's how to port the stock one.

porting a stock intake helps marginally, but its pretty much a loosing deal compared to using a better intake matched to better heads, and don,t forget that your converter stall speed and rear gear ratio can help a great deal, as can use of a low restriction exhaust and headers, and the melrose 1986 headers and exhaust can be adapted, but again, emission inspection may be a problem even if the car runs great and passed the sniffer testing
http://www.melroseheaders.com/products/ ... ms/c-4.php,


5. Why won't a cat back from an 86 C4 work on an 84? is there a different cat? I would like to upgrade the exhaust but don't want the drone of flowmasters any more, however, I have never run flowmaster's behind a cat before, will the cat mellow the flowmasters out alot?

a decent muffler/exhaust shop can adapt a lot of c4 exhaust systems to work correctly on your 1984 but passing emission inspection may require limited choices

6. And finally, since the 05125 NOS systems setup for crossfire is no longer in production, is there a way I can run nitrous on this crossfire?

several nitrous systems can easily be adapted,or fabricated, from easily accessible components once you understand how nitrous works


I know this is a long first post, but I am dying to get down to business! I am looking at some world s/r torquer heads today, and am going to get this show on the road! So, thank you in advance, every bit of information I can find on this thing will help me make it into the crossfighter it deserves to be. I am also already looking for a fuel pump upgrade and learning what to do about the idle being so inconsistant
It's not a true lope like an isky mega cam, it's like a vacuum issue or something i suspect. I will fix it.. Thank you, so much, truly. I here grumpyvette is the man to ask about all things C4.


there are FAR better heads than the world s/r torquer heads, ID STRONGLY suggest some research be done before WASTING your money on those
 
That is awesome... thank you very much! Finally someone who knows... ok, I didn't get those torquers anyway, they looked beat up. I want aluminum anyway, I'm looking for a 175-180 cc intake runner right? and about a 74cc chamber? Please correct me if I'm wrong! I will read the things you suggested, I am very serious about my cars, you will see as time progresses. I will read the entire library of congress if it will show me how to roast my tires from a 60mph rolling start!
 
so the 2030 is a 204/214, the stock one is a 202/207. the 2040 is a 210/216! that's much bigger, but I don't want it to fall on it's face from being overcammed, I want it to pull HARD. Will the increase in the exhaust duration of the 2030 make that much of a difference? cause the 2 degrees difference in the intake side won't add up to much.
Would it make a difference if I put a 1.6 rocker on the exhaust side? on the stock cam? it would increase my effective duration by @ 2 degrees and increase the valve speed, as well as the lift, could end up acting like a 2030 without a cam swap or ecm change. What do you think?
 
crossfighter said:
so the 2030 is a 204/214, the stock one is a 202/207. the 2040 is a 210/216! that's much bigger, but I don't want it to fall on it's face from being overcammed, I want it to pull HARD. Will the increase in the exhaust duration of the 2030 make that much of a difference? cause the 2 degrees difference in the intake side won't add up to much.
Would it make a difference if I put a 1.6 rocker on the exhaust side? on the stock cam? it would increase my effective duration by @ 2 degrees and increase the valve speed, as well as the lift, could end up acting like a 2030 without a cam swap or ecm change. What do you think?
Click to expand...


do you have an auto transmission or manual trans?

if your going to get better heads, I would NOT suggest the ZZ4 heads as they are not a huge improvement.


these are
http://www.airflowresearch.com/index.php?cPath=24_25
AFR 180cc SBC Eliminator Street Cylinder Head
The Small Port, High Velocity Torque Monster
AFR 180cc SBC Cylinder Head
Click to enlarge

The Emissions Legal (versions from 1969-94 with heat riser, CARB EO #D-250-2), 180cc intake port small block Chevy eliminator cylinder heads are available in your choice of straight or L98 angle plug versions. These performance heads feature a 75cc or 65cc combustion chamber with a 64cc exhaust port and a 3/4” thick head deck (ideal for nitrous or blower applications.) Standard valves are lightweight 8mm 2.020 intake and 1.600 exhaust with AFR’s hardened ductile iron interlocking valve seats. The exceptional flow characteristics, ideal operating range of idle to 5500 rpm (higher rpm ranges possible depending on combination of parts), 23° valve angle, and standard valve spacing make this the perfect street aluminum cylinder head for 327 cid to 350 cid engines from 1955-86. Also available for 1987 to present engines with center bolt valve covers and 2 center intake bolts at 72° angle, AFR Part #0919. No special parts are required (see footnotes here). Vortec style cylinder heads available too. Dual valve cover bolt pattern is standard. Exhaust port is raised .100 over GM L98 cylinder heads.
Note:
Hydraulic roller cams typically experience valve float at 6200-6400 rpm because of their fast ramp rates. AFR suggest you upgrade your springs to AFR part #8605, 1.290 O.D. with higher spring pressures and use our Patented “Hydra Rev Kit” to reduce chances of valve float associated with rpm 6200 or higher.
180cc SBC Street Aluminum Cylinder Head Flow Chart
180ccSH.gif

http://www.airflowresearch.com/product_ ... ucts_id=35

http://www.summitracing.com/search/?keyword=0918&dds=1

yeah, expensive but a much better value that thezz4 heads
but your still restricting the engines potential unless you get the better intake, and cam that support the increased head flow potential
 
Ok, so then if I can find some L98 aluminum heads and have Bob Gromm port them for me I should get a similar result, I can get a new pair of aluminum L98 corvette heads for 300, and Bob will clean em up. AFR has a superior product, that's for sure, but I'd have to wait and save for a year to buy em. Ok, so now I need to talk to CFI and pre-buy a renegade intake, I guess. I was on GM performances website last night, I wonder if the cam from that 290 hp crate engine would be a good choice? It's on a 114 lsa, might work with the ecm? I couldn't believe the numbers on the stock intake when I saw them today, wow. Can't make much power with that.
 
Ok, so I see the reason L98 heads won't work. The chambers are way too small. I'd end up with 11:1. I can't afford 1500 for AFR's. I wonder how much these stock heads would flow if I had them ported, or if there's enough material in them to even port them. Darn.
 
everything's a compromise, you CAN build an engine that will kick butt, but its probably going to take a bit mote time,cash and effort than you though it would going into the project.


read thru this thread, and sub linked info
viewtopic.php?f=52&t=462&st=0&sk=t&sd=a&hilit=porting+help

YES you can improve the stock heads but its un-realistic to expect stock cast smog heads like the #624 on that crossfire engine to produce flow numbers close to the mid priced aftermarket heads available, and by the time you put the time and effort into the stock cast heads and required machine work your probably going to be close to the cash,value that the aftermarket heads with their larger ports and valves cost.


your not the first guy to think,"hey I don,t have a grand to spend on heads ILL just port my stock heads"
well some guys do succeed in increasing the flow and power and some guys ruin their heads in the process but about 99% eventually find out that porting the stock heads took time and money, that was wasted,and better spent saving for the aftermarket heads, but don,t make the really common mistake of wasting cash on upgrading to inferior heads, the stock heads flow about 190cfm, the aluminum vette heads don,t flow all that much more, for a good boost you want a head that flows a minimum of about 250cfm at .500 lift, but remember the intake runners and cam lift and duration, and exhaust headers must allow the heads to flow, its silly to select heads that flow 270cfm at .700 lift if your cam max lift is .530, or an intake that stalls at 240cfm, or select a cam thats designed to produce killer power in the 4500rpm-7500rpm power band then use an auto transmission and stock converter,rear gear, etc. the car so is stays in the 1200rpm-5500rpm band then shifts down to the next gear.


look thru these links carefully
viewtopic.php?f=52&t=92&p=7882&hilit=flow+numbers#p7882


these are some of the best current values

http://www.jegs.com/i/Brodix/158/1021004/10002/-1
1021004 - Brodix IK180 / IK200 SB-Chevy Cylinder Heads

http://www.summitracing.com/parts/TFS-30400001/

http://www.summitracing.com/parts/TFS-3 ... /?rtype=10


BTW
I heard that they are now currently shipping those renegade intakes

http://www.crossfireinjection.net/DCS%20Renegade.html

f430v6.jpg

vi6hx.jpg
 
This is excellent... so am I looking for a 62-64cc chamber? by my math that's @ 10.2:1, correct? Not too high for an aluminum head on pump gas, right? Or should I go with the 72cc chambers? I would have to use the trick flow's cause the brodix have no heat crossover and I still have to smog this thing. The trick flow will be emissions legal. the 72cc heads would end up being @ 9.36:1, right? But I like the description, high velocity ports for torque, but good top end. Perfect! And the price is right... But chamber size I don't know which to pick.
 
the lower compression ratio would be the better option on a street driven car, as its far less likely to get into detonation issues with crappy fuel.
 
ok, so at this point I am getting the exhaust upgraded on Saturday. Then I will get the Hypertech stage 2 thermomaster and a 160* t-stat and a K&N air filter. I have some 1.6 rockers I may try next, see what it does, if I get bored while I'm getting this other engine together. I'm gonna take my time and plan real careful before I make any more choices about cams and heads, cause I want the computer to work right and it still to pass smog. I spoke with hypertech, jet, and motorvation today, trying to find a way to have a prom made to work with what I want and -no go. Jim at CFI said he can get a prom burned for me so I will follow up with him monday, but until I know for sure I can get the right chip there's no point in swapping a cam. Isky says that I can run a cam as big as the 270/280 mega with a stage two chip, but I have heard from others that might not be true, although I love isky cams. The 270/280 as well as the 264/270 mega are on a 112 lsa, which supposedly will work with this, but I need to know for sure. Otherwise, I'd rather run it with these mild mods for a minute, sell it and find a way to get an LS1 car. 97. Would be the easiest way to achieve my goal. Would also have to make car payments again for a while. I see 97-98 hardtops in the 11000 dollar range on craigslist now, so it could happen, I guess. I just want this thing to live up to it's name. I also learned today about the difference in the calipers from c4-c5, and learned I'll either need to swap in c5 calipers or run a 3/4 inch thick adapter plate for the rims to be set correctly, I have 97 rims, and the 275/40's scrape the inner wheel well pretty bad. At 69.95 ea. those spacers are not a cheap solution. I can get a full set of c5 brakes, complete for 250 but i have to find out if they bolt up or have to be adapted? and if so, how? Wow. bigger project than I thought, but I'm in it now, so here we go, eh?
 
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