8
87vette81big
Guest
Smaller carburator inlet valves control erratic fuel pressure spikes better Rick.
.095"-.110".
.095"-.110".
TBucket Engine Project (Dart SHP)
- Thread starter Indycars
- Start date
8
87vette81big
Guest
If you feel up to it Rick, remove the bottom plate on your Holley Red pump.
Pump can stay mounted in T bucket.
You will see slide valve.
Carefully clean it and lightly polish with 600 grit & then 1500 wet and dry sandpaper.
Fuel pressure will be more stable.
Pump can stay mounted in T bucket.
You will see slide valve.
Carefully clean it and lightly polish with 600 grit & then 1500 wet and dry sandpaper.
Fuel pressure will be more stable.
bytor
Well-Known Member
Indycars said:
Correct, a baseline log is very important or you will go in circles as you start tuning. You will need to make a few log runs under some load like up a hill while slowly pressing the accelerator from idle rolling along around 30mph to WOT. It will be kinda tricky with your automatic so you want to get in 3rd or 4th gear and don't accelerate hard enough for it to downshift. You want to keep it in a high gear.
8
87vette81big
Guest
The last time I used one of I had one of those tiny fuel pressure guages Rick it was on my old TA back in 1996. It rattled apart on me. Didn't leak gasoline but the glass broke.Indycars said:
Out screwing around and hitting Redline rpm danger zone I Love but Grumpy hates.
Its fairly accurate. Good enough fpr this weekend .
8
87vette81big
Guest
The Autometer 2-5/8" face diameter liquid filled guages are what I preffer to use Rick.
All mechanical with Braided Teflin lined Steel crimped premade #4 lines 3-4 feet in length.
One mounted on my 70TA.
One mounted in my 1963GP.
Both Mallory Comp series fuel pump fed.
87 Corvette has no fuel pressure guage for now.
Stock EFI TPI engine.
All mechanical with Braided Teflin lined Steel crimped premade #4 lines 3-4 feet in length.
One mounted on my 70TA.
One mounted in my 1963GP.
Both Mallory Comp series fuel pump fed.
87 Corvette has no fuel pressure guage for now.
Stock EFI TPI engine.
Got my first usable log file after working out all things I didn't know how to do.
There is still plenty more the system does that I'm not aware of yet, but at least
I have scales for all the logged variables. Things like that that weren't happening
at first and took some time to discover what I needed to change.
The trans shifted from 2nd to 3rd and (I think) can be seen at the 3.2 to 4.2
seconds where the MAP numbers drop and then start to pick up. The road is up
hill somewhat like Bytor suggested. I slowly depressed the throttle until at 10.75
seconds I reached full throttle. For now the butterflies in the carburetor only open
to about 85° and you can see that on the chart. For now that is full throttle.
NOTE: The chart goes out to 12.5 seconds, you might have to save the image to your
computer to see everything, right click on the image and then click on "Save Images As".
I figured it needed to be that big to see the details.
I made a 2nd attempt and was shooting video where I had to abort very suddenly when
I saw the police coming toward me. I saw him when I was about 1/2 way to WOT and
he was about 250 feet away. I think he looked at me but by then I had slowed enough
and was in a higher gear to keep from making too much engine noise. I decided I had
used up all my luck for the day and headed home!!
There is still plenty more the system does that I'm not aware of yet, but at least
I have scales for all the logged variables. Things like that that weren't happening
at first and took some time to discover what I needed to change.
The trans shifted from 2nd to 3rd and (I think) can be seen at the 3.2 to 4.2
seconds where the MAP numbers drop and then start to pick up. The road is up
hill somewhat like Bytor suggested. I slowly depressed the throttle until at 10.75
seconds I reached full throttle. For now the butterflies in the carburetor only open
to about 85° and you can see that on the chart. For now that is full throttle.
NOTE: The chart goes out to 12.5 seconds, you might have to save the image to your
computer to see everything, right click on the image and then click on "Save Images As".
I figured it needed to be that big to see the details.
I made a 2nd attempt and was shooting video where I had to abort very suddenly when
I saw the police coming toward me. I saw him when I was about 1/2 way to WOT and
he was about 250 feet away. I think he looked at me but by then I had slowed enough
and was in a higher gear to keep from making too much engine noise. I decided I had
used up all my luck for the day and headed home!!
Last edited:
8
87vette81big
Guest
Need to find a seldom used country road Rick.
Lots of them around my farmhouse.
Also I have seldom used roads to Peoria & Chi Town.
Could spray paint 0 after 55, 65, 70, 80 mph posted speed limit signs.
Just point to the 5 ' O & see.....I wasn't speeding. :mrgreen:
Lots of them around my farmhouse.
Also I have seldom used roads to Peoria & Chi Town.
Could spray paint 0 after 55, 65, 70, 80 mph posted speed limit signs.
Just point to the 5 ' O & see.....I wasn't speeding. :mrgreen:
bytor
Well-Known Member
Your MAP signal looks odd. If I'm reading it right your at 6hg when your at WOT.. Thats not right is it?
You will want to make several runs to the the feel of creating a nice log pull from idle to WOT. Once you can consistently make logging runs, you will be ready to start tuning. I found that my 650 Speed Demon suffered from too much emulsion on the primary circuit. The circuit would start normal then lean out then go rich and lean out again. I ended up plunging the middle emulsion hole and making the upper one larger. The helped thing out tremendously for me. Tale a look at post #334 in the following http://forum.grumpysperformance.com/viewtopic.php?f=69&t=6962&start=176
You will want to make several runs to the the feel of creating a nice log pull from idle to WOT. Once you can consistently make logging runs, you will be ready to start tuning. I found that my 650 Speed Demon suffered from too much emulsion on the primary circuit. The circuit would start normal then lean out then go rich and lean out again. I ended up plunging the middle emulsion hole and making the upper one larger. The helped thing out tremendously for me. Tale a look at post #334 in the following http://forum.grumpysperformance.com/viewtopic.php?f=69&t=6962&start=176
bytor said:
If you mean the MAP should be reading lower than 6 inHg of vacuum, then it's because
the sensor bottoms out and won't go any lower. Lower being numerically, which is actually
a higher pressure or getting closer to atmospheric pressure. Maybe I need a different MAP,
how low did yours read??? If I didn't read your statement correctly, please elaborate ...... Please!!!
When you refer to post number 334, that's actually your TOTAL number of posts, if you look it's
already up to 335. Each post does not have a number that is visible in this forum. No matter,
I found your posts about tuning and I'm reading and have been looking at them already. This
is not something I'm going to get overnight. I've had a revelation, I found that the easy part
was the installation, the HARD part is making sense of the data!
Innovate has much better info about making use of the data than AEM, which is pretty much
non-existent. So I'm reading the Innovate articles you posted and most likely it will be a few
days before this all starts to gel for me.
At this time I've made NO changes to the carburetor. I did make another run and slowed the
data rate from 20 samples/sec to 10 samples/sec hoping the smooth out the chart line. That
didn't help, I wonder if Innovate uses a smoothing function on their charts, your look soooo
much smoother than mine.
Everything I've said above is suspect, while I try to comprehend this new toy, so please anyone
that see's something questionable, please speak up !!!!!!!!!!
8
87vette81big
Guest
I will look in the morning for You Rick.
AEM was designed for Racing Professionals. Tuners day in day out making a living at it.
Is sounds to me the Speed Demon 650 Carb is too small of Cfm.
The engine wants a bigger cfm carb.
AEM was designed for Racing Professionals. Tuners day in day out making a living at it.
Is sounds to me the Speed Demon 650 Carb is too small of Cfm.
The engine wants a bigger cfm carb.
8
87vette81big
Guest
Ok Rick.Indycars said:
Just read up as much as you can today.
I will look at the charts this afternoon .
BRODIX HEADS YOU HAVE ARE TOP 2-3 Made.
8
87vette81big
Guest
May have a hidden exhaust back pressure issue WOT.
Suspicions .
Suspicions .
bytor
Well-Known Member
Indycars said:
Silly me on the posts number, that makes since.
Correct, 0 inHG is no VAC or atmospheric pressure. At WOT, I was getting like 1 to 1.5 inHG. which I think is normal.
It took me a while to get familiar with the LM-2 logging data myself and what it all meant. You have a nice setup, you will become an expert as you spend more time with it.
Bytor,
I found the link below in your post. This guy wrote a straight forward
article with just enough detail to get me going and not overwhelm me
with too much info.
This is an excellent article with graphs for the beginner like me.
http://thefactoryfiveforum.com/showthre ... Tuning-101
Removed the Demon carburetor a couple of days ago so I could start with my
AFR/AQ1 and carb tuning adventure. Last night and today I’ve been measuring
several different orifices that I will be drilling so that I can install removable
brass jets. The new jets will be made from brass set screws purchased from
McMaster-Carr. I bought three sizes since I was not sure which ones I would need.
Total Cost Shipped was $27.15
6-32 Brass Set Screws – Qty 50, # 92991A142
https://www.mcmaster.com/92991A142/
8-32 Brass Set Screws – Qty 50, # 92991A188
https://www.mcmaster.com/92991A188/
10-32 Brass Set Screws – Qty 50, # 92991A824
https://www.mcmaster.com/92991A824/
As I go thru drilling the different size brass jets, I needed a way to keep them
organized. So I bought a 28 compartment pill organizer. When I can’t drive
anymore, then I can repurpose it for my actual pills!
Most of the orifices are recessed, so if you are doing this, then be sure to
measure the smaller hole. That’s the one that is doing the metering of air
or fuel.
Question for Bytor …….
Did you drill the orifice bigger so that you could increase or decrease the size
with the new brass jet??? Then thread the larger hole just above it??? Drilling
the larger hole to accept the tap.
If you installed a larger brass jet, but the orifice was still the original size,
nothing would change since the original orifice is still restricting/controlling
the flow.
The drill bits, especially the smaller ones looked like they were just sheared
off which left it ragged and with burrs on the shank. So if I used that bit to
measure a hole, I polished the end and then tapered it with 1000 grit Wet-r-Dry
sandpaper and WD40.
The sizes were not very accurate or consistent within a particular size. The
set I ordered had 5 bits per size. For example, I could open a #68 tube which
should be .031 inches in diameter, but it could vary .029 to .032 inches. Decided
MY STANDARD would be MEASURING the drill bits with my Brown & Sharpe digital
calipers as my standard. Those will be the numbers you see in my photos. It best
to pick one Way of doing something and stay with it. I checked them against a
one inch standard that came in my Harbor Fright micrometers. Yaw I know ….
That’s No Real Standard You Idiot!!!
Below is the documented sizes. I had to sometimes interpolate between two different
drill bit sizes, one too small and one too larger. So the real size must be between the
two. Like using go/no-go gauges.
Primary Metering Block
Secondary Metering Block
Main Body
Reference Links Here
http://motorsportsvillage.com/forum/vie ... f=6&t=9717
http://www.motorsportsvillage.com/forum ... f=6&t=3742
http://www.clubcobra.com/forums/holley- ... rcuit.html
http://motorsportsvillage.com/forum/vie ... 3&start=45
http://www.ffcars.com/forums/17-factory ... nting.html
Hope you enjoy this post, like most of this length I make are very time consuming.
This one took 2.5 hours to take photos, sometimes I would take 4-5 for just
one that you see. Then I needed to annotate the photos and develop the text above.
Tomorrow I hope to start drilling and taping if I can stop shaking during the process!
Last edited: