I have an '87 GTA 350 TPI MAF car. List of mods include:
Forged pistons, flattops
T/F 23 degree heads
Comp Cam, 220/230....510" I/E lift hydraulic roller
Crane Gold race roller rockers 1.5's
Ported Plenum
9.5:1
160 stat///180 operating temp
Catco high flow cat
Airfoil
K/N
No airbox
SLP runners
Wells MAF unit w/ no screen on the outlet
45 psi of fuel
30 lb Ford injectors
Shorty headers w/ 3" Dynomax cat back
Crane HI-6S ignition w/ HEI module
2500 rpm stall, lockup
3.73 posi

First off, I am using WinBin, Winaldl and the PP2 and the 165 $32b bin.

I have always worked on carbed muscle cars so this is the unknown for me. I assembled this car a few years ago and had EdWright burn me a custom chip that fit my needs.
I have started buring my own chips a few weeks ago. The car baselined at 14.7 sec. before these upgrades. The mods were done a couple years ago and I figured there was more hp left in the chip. I have reburned this 29c256 chip about 70 times already and have done a lot of tuning using the MAF and spark advance tables. The car runs around 120-132 BLM's between cruise mode and idle. The plugs look a little light colored to me, off white electrode and at WOT, the O2mv are around 880. There is very little knock, about 10 cells total have 1. Last week at the track with a R/T of .70, the car ran 14.4 at 96mph. This was with very, VERY little tire spin off the line and shifting at 5200 rpm to keep the engine in its powerband. In 3rd through the lights I was at about 4800 rpm. I have added and removed timing from the spark advance tables. Initial timing is 6D.
Based on what everyone else is running, this seems a bit too slow for my setup. I recently decreased the PE vs. rpm in the 2800 cell from 6.25 to 2.34 and now there is a huge difference in low end power. Car will spin em at will in 1'st. Not good for racing , but it was a test to see what that change would do.

Are there any changes that should be made to any of the AE or PE tables to improve midrange and upper rpm HP???? I'm new at this so I have just been changing a few values here and there using small changes and then logging data. I have countless doc's on AE,timing,MAF,etc., but I have not seen too much on PE vs. RPM values. It's just really depressing when an NOS injected **** burner runs a 12.9 right next to you. I was thinking with my setup there should be quite a bit more hp in there somewhere. The only thing bothering me is the flow of the Wells Su-145 MAF sensor being too low. So I was looking at supercharging next year sometime.
Any other info available upon request. I have lots of LOG data in excel forms.
Thanks in advance.

 

You should consider port matching the intake to your heads, at minimum.. Personally, i'd ditch the tpi setup for a better mpfi setup, like hsr, etc.

Your running more compression than my old setup, and have better heads, adn that ran n/a low 13s.. Theres something wrong with your combo, and I think its the intake.

A few people will chime in and say the stock tpi setup is good for whatever, and they've had luck wth it. I say, they'd find if they remove it they'll go a second faster. Some people have too much loyalty.

Another thing I'd do is ditch the maf setup, and start tuning a '730.


-- Joe

 

Ummm....too many cheeseburgers???

Seriously tho, you should try the DIY PROM or DFI and ECM boards for a better response. Maybe someone could help you with the tables you are seeing. I'm just barely starting my own chip burning as well.

 

Acutally I have a Ed Wright Chip, he has made 4 so far and it still runs like crap Im tempted to start burning them myself

 

It's not too many cheeseburgers...LOL..I am only 158lbs. soakin wet.
I did open up tpi base ports somewhat. Something is just amiss and I can't put my finger on it.
I did, run for one week, a performer RPM manifold that I modified to fit the 23 degree heads and a Edelbrock 750 carb. The setup definitely had more up top to about 6200 rpm or so, but I can't say it would have run a second faster in the quarter, maybe a half second, but that was before I started playing with the chip settings.

thanks for the input so far.

 

It's almost impossible to get a good chip burned through the mail. At the very least you need a dyno, scanner and a WB02 hooked up to the car to take readings. Then it takes several tries to get it right. There are a lot of variables to consider. Again, ask these questions on the right board and you might get some ideas to help you. Even tho you've burned the chip 70 times its just a matter of getting the right numbers to make it work. I am not familiar with MAF because I switched over to SD. Your fuel tables could be a little off. It could be a number of things. Sorry I am not much help.

 

Your not kidding about missing a lot of horse power. I can tell you that the MAF is not your problem. IMHO the cam is to big for your set up.

The stock intake is choking the flow into the Trickflow heads. You have a big mismatch. Those Trickflows flow 253CFM and the stock base flows maybe 200 CFM. Still this is not your big problem.

Did you degree the cam when it was installed? I have heard of cams being off by 7 degrees when installed straight up. That is why they need to be degreed and installed accordingly.

What is the total timing you now have? You should be at least 28 degrees with the Trickflows as with the new design they do not require the big timing advance. Now with your 9.5:1 compression ratio you should probably be a few degrees more than that.

By the way I have a very similiar setup with my 1989 GTA. I just had the engine rebuilt with new parts. I also have the Trickflows with flat top pistons but I have a 10.5:1 compression ratio. How did you wind up with a 9.5:1 compression ratio? You must have a lot of valve relief cut into those pistons and a thick head gasket.

Back to the cam I would look into seeing if it is degreed properly and seriously look into a smaller cam maybe around 212 degrees on the intake for a LTR TPI. Now if you go to a super ram setup then that would be a good cam but not for TPI. Allen

 

What? No..

His cam is smaller than mine, when I ran the LTR setup. Going to a stock profile cam to fix a broken base plate makes no sense.

sparks454:

The stock base is the first of your problems. Hog it out to match the heads, or get an aftermarket and hog that out. OR just go with a better setup.

That cam is 112 lsa, right?

I'm not gonna get into the maf/map debate on here, but I'll tell you this.. I can repin the car in 40 minutes, I have all available ecms to me.. I tried 165 running both 32, and $68, tried '730 running $8d, and $58.. I know what goes faster. I'd be happy to help you on the tune if you wanna start a thread in diy_prom.

Based on what you said from your scanner output, I think your engine is running the the best of its potential, giving the allowed amount of air to enter the head. Whats the airflow show in the log at WOT from 3k to 5200 ? I bet you havn't even begun to hit the upper limits of that maf, yet you've allready exceeded your baseplate.

Once you fix the intake manifold, you can work on getting rid of the maf.

-- Joe

 

I stuck another post on here asking for intake opinions based on performance and affordability. I'm gettin hitched this October and the budget is limited at the moment. I know that stock base is a bottleneck. I built many a motor and have tested lots of cams. This cam was degreed in and I'm running a thicker head gasket to lower comp. a little. Supercharger coming sometime next year.
I think that cam is just right for the motor, especially looking at future mods. It has a LSA of 114 so it idles pretty good.

Airflow at WOT does not exceed, but hits 236.G/S.

I also know that the MAF sensor is bottleneck too, but first things first. That intake setup has to go. I have to agree also that it's running as good as it's gonna get. I've made many changes to the PROM w/ very little improvement.

Timing is from 41.8D at the 4800Rpm mark from 32g/s to 112g/s and from 128-208g/s it declines from 40.08-35.16D. this is only the top row of cells in WinBin and not to forget the initial timing is 6D. If the timing is bumped up more it starts knocking.

Joe, I would like to send my bin to you for review if possible. Maybe you can see something I have overlooked. My O2 reads 860-890mv at WOT. Craig Moates said is should be about 800-850mv. Let me know.

Thanks for the response.

 

Just tossing this out...but what pushrods are you running? All the info I've seen on Trickflow heads says they require different pushrods.

 

I shoot for around 900mv on mine, but thats what it likes. Every motor is different.

I'd like to see your bin. email it over to me with a log if you can.

-- Joe

 

thanks Joe. I will get the bin and log files to you in a bit.

The pushrods are hardened ones From Summit that go with those heads. That's about all I know about those.

I live about 35 minutes from there so it's pretty convenient.

Thanks,
Chris

 

Using the wrong pushrods won't cause it to run wrong, will simply wipe out the retainer/lock, and top of valve.

Lets forget about valvetrain geometry for now. I wanna see your logs + bin.

Then I wanna see you get a real intake

If those heads flow 253 cfm, with your cam, compression, and a real intake you should be running low 13s at least. Unless your at like 6,000 ft..

Another thing I noticed. Your fuel pressure. Is that 45psi with vac disconnected? if so, i'd like you to turn it up to around 50 psi. (assuming your pump can deal) then compensate your injector constant, and maf table to get your blms back in the 128 range.

If anyone decides to chime in and say "why raise the fuel pressure, if your gonna retune anyway" well. Go do a search.


-- Joe

 

that pressure is at WOT. At idle I have 40psi. The bl's are running between 120-132 depending on idle or cruise mode.
I sent you a few of latest log files to look at and my latest bin.

I like the performance and price of the HSR. I thought I read somewhere that you have to remove a part of the hood support for clearance to make the Holley fit??? Does it have an EGR provision??

-Chris

 

No egr no.

You should really up your fuel pressure a little.

I dunno about the hood. I dont have a hsr, or a stock hood.

-- Joe

 

I just turned it up to about 43psi at idle and 48 w/no vac.

Probably go for a drive shortly.

 

Nothing wrong with the stock intake, although you do have aftermarket runners.

I ran 13.7 @ 101 with all stock stuff on a 9:1 383 with afr heads, headers, and a convertor, everything else was stock. I think you have some little tuning issues to resolve. You should at least get down to low 13's, high 12's with that set-up.

You will have to go back over the car with a fine-tooth comb to see where the problem could be. Intake/exhaust gaskets matched to the intake/headers, spark plug gap and selection, etc.

You didn't list your 60 ft times, I am assuming that you are spinning at the line?

 

That time was with no tire spin and a 2.1 60' time w/.7 RT. I shouldn't say NO spin, they did squeek a little but there was no spin to mention. AFter that day, all I did was change the PE vs. RPM value in the 2800rpm cell from 6.25(136) to 2.34(131) and now it'll smoke 'em in 1st...what's up with that??. It was just a test to see what the change would do, but then I changed the other cells from 3200rpm up to 6400rpm from 0(128) to 11(143) and then to -11(114) with NO AFFECT at all.

I decided to leave the 2.34(131) at the 2800rpm cell because with a good set of stickier tires than I am running it should hook up and bring down that 60' time into the 1.7sec range or so.

The plugs are what's recommended for that head, Autolite 3924. Gapped now at .035 and have tried upto ..050 w/ no change.

After 1st gear though, it just seems to run pretty flat unless I'm expecting too much, however the time slip shows the same story.

Chris

 

I tune by zeroing out the pe vs. rpm table, then tuning the pe vs. coolant temp first setting them to 22.7. Once I get the o2's in the ballpark by changing values +/- 22.7 in that table, I then fine tune with the pe vs. rpm table based on scanner data telling me where it is rich/lean and subtract/add based on rpm.

You were probably rich at the spot where you reduced the pe vs rpm fueling.

 

i see u have ford injectors....no wonder..lol

 

I would think about doing a comp. test, or better yet a leak down test just for starters!! You should make sure that bottom end is proper first, then move on from there. Once you are sure the compression is tight, then start playing with some more tuning and port matching. I am sorry to be the one to say this, but you are missing way too much power for this to be just a tuning problem. And port matching will not give you an extra 1.5 seconds and 6mph at the track. Have you tried the stock chip yet?? Sometimes that will tell you how far off your tuning really is(when the car runs stronger with a stock chip, you know you have a tuning problem,lol). Anyway, I am not trying in anyway to put your car down, trust me I have had my share of issues!! With everything you have the way your car sits, you should be atleast at the mid 13 mark now.

 

Thanks to everyone for the input. Maybe it is those Ford injectors....hummm..anyway, The PE vs. rpm table is zero'd out from 3200 to 6400 rpm. I moved the values +/- 11 each side of zero in that range with no change in performance. Maybe it was not enough.

My PE vs. Temp from 133degrees on up is 22.66. Your thought is to increase that first correct???

Compression check yielded 135psi +/- 7% last year when I tested it. I have not done a leak down test yet, but this block, rings, bearings, pistons and heads have only about 5000 miles on them.

I will check comp. again in a day or so. The plugs still look pretty light to me so it really seems like a fuel issue.

by the way, the stock chip nor the Hypertech Thermomaster that I have will work because of the increased injector size(30lb.). I can pull the tables from the Hypertech chip and review those, but I can't see that helping me in anyway from where I sit now.

Thanks,
Chris

 

I still say its partly his intake. I don't care if people have gone 12s with them. If they had replaced their intake, they'd be going 11s.


I didn't get a chance today to look at the logs or bin. perhaps in the am.

-- Joe

 

I did adjust the PE vs. Temp tables from 22.3 to 25. The run seemed not as fast and the O2 counts were at a steady .897mv, up from .83-.88mv. Some smoke also when WOT was hit. Plugs still look about the same.

I'm also yielding 238.3 g/s at WOT w/ a TPSV of 4.48V. Does this indicate the intake assy. is flowing pretty well w/ the stock base or would/should I see this value go up to near 255g/s with an aftermarked base??Just curious.

Should I try reducing the PE vs. Temp value from 22.3 to say 18 or so and see what happens or should i work on the PE vs. Rpm table instead.??? The car seems to run pretty fat down low at 25.

Thanks,
Chris

 

If the plugs look fine, then start taking fuel out. The only real way to test is at the track or dyno/wideband and a stretch of road. Go back the other way from 22.7, say at 21 and see what the car does.

 

Hrmm.. I wanna run those numbers by a few people.

-- Joe