What harness/ECM combo are you using? I noticed the LT-1 style throttle body, so did you just switch the connector to use the newer style TPS....??

 

Yes that is a LT1 throttle body from Arizona Speed and Marine. It is the monoblade. I just made up some adaptor harnessess for the TPS and IAC. Not hard to do as the wire colors are the same.

The one for the TPS is wye shaped so when I install the 4L60E with the TCI transmission controller all I will have to do is plug it in.

Factory harness modified slightly for the MAP system. The factory ECM as used on the 90-92 f-bodies.

 

Dont forget its custom tuned by me.

 

Yep, Kevin is the tuner. We need to set up another dyno tune session sometime next month now that my drive shaft is upgraded.

By the way DynoDon is fixing the exhaust and is doing a great job that will even be better than the old one if that is possible. No back pressure allowed.

 

When I tuned the PROM for my current setup a few years ago, I had a LM-1 wide band hooked up as well. What I noticed is that the ECM showed 128 while the WB showed lean (in the mid to high 15's). When I richened up VE to make the WB happy, exhaust smelled quite a bit richer and BLM's only went to like 115 (never bottomed out at the 108 threshold) and the car didn't feel as quick.

Have you noticed the same? What are your BLM's at while not in PE ?

Also, if you are able to do so, try using a Holley 58mm twin instead of the mono-blade while making a pull. You may be surprised to pick up some tq and maybe some HP. I ran a mono-blade as a test and the car felt like it lost a little.

 

I have not data logged the latest setup. I should get the car back Thursday and can do some data logging after that. I have not noticed any difference between the 58mm and the monoblade at this point in time driveability wise.

My KPA's are up slightly with the monoblade. I just want to make sure my plenum is as close to atmospheric pressure as posible at wide open throttle throughout the rpm range. This time around we are going to play with the exhaust some on the dyno. We have test pieces to replace the catalytic converters do see what happens.

On VncentZ28's car it did not seem to make much difference with cats or without cats.

 

BLM's are around 128 as they should be. I cant be perfect so as long as they're between 120 and 140 and they move around between those two ranges, its good. The weather plays a big effect on the tune so you'll never get it to be 128 all the time.

We havent put the wide-band on his car in a while so I dont remember how the wide-band O2 compared to the narrow-band O2 on the car.

 

I've managed to keep mine between 124-130 across the board regardless of the weather, however the WB shows on the lean side eventhough I'm within spec on the BLM's.

I was just curious if you tuned the car to make the WB happy only (14.7 to 13.0 at WOT) and while doing so, what BLM range did the narrow band show....

 

Was wondering on what the status of this was? Did you ever find the problem?

I was thinking the other night about me putting one of these on a mild LTR 427 with the first intake like I mentioned a couple months back, and I was wondering if maybe the dropoff was due to the engine losing it's tuned effect at those RPM's? Maybe the intake pulse is hitting the back of the valve when it's not quite open enough to take advantage of the accelerated charge, or perhaps it's blowing some out the exhaust. I dont know your cams specs and dont have the time right now to find them unfortunately.

Whatever the reason is, it's not filling the cylinders well at those RPM's, thus, your loss of HP. At least, thats my guess.

I'm still biting at the lip to do mine, I've just had no time lately and I've got to get done my LS7 first. I'm still planning on the OBDII 427 TPI idea, even though I dont have a car to put it in yet, lol

 

Going back on the dyno this Saturday. I have recovered the lost horsepower by changing out the valve springs. They had weakened considerably. So now the goal is to break the 350rwhp barrier.

Here is a recap. Installed the First intake manifold and upgraded SLP runners. Flow would be around 40cfm over the previous intake system. No increase in horsepower was made. Also included in this is a 1300cfm monoblade throttle body and a bigger air filter. No increase in horsepower.

Installed a new custom cam. Went from the XFI268 cam (218/226) to a Mike Jones 228/228 cam with slightly higher lift and inverse radius ramps. No increase in horsepower. By the way the cam and intake are tuned for peak power at 5800-5900rpm with this combination.

So whats next? The exhaust? We are going to experiment with no cats and a ever so slightly better Y-pipe. Should have the results this Saturday night.

If that does not show anything then we will go to an open exhuast with 18.5" collectors and see what that does. Again tuned for the 5800-5900rpm peak power range.

Maybe it is my torque converter?


The First can be made to flow enough for your 427. You should be able to make it flow well into the 300cfm range easy enough.

 

Could be lots of things. Thats one of the things that sucks about tuned intake manifolds...you have a smaller margin of error as opposed to an intake like a single plane or an LT1. Non tuned intake will accept almost any type of camshaft and work decent at least and make power until they stall the port...tuned manifolds only work well with certain camshafts because you have to time that intake charge. Everything is that much more important, because the events in the engine have to be timed to occur at a certain time based on the intake manifold.

I still think TPI kicks *** though I like the TPI, the LTx and the LSx all about the same because I like something different from each I build, and they all offer something different. I love 'em all Guess thats why I like combining them sometimes.

Your converter isnt locking up on you is it? What stall? What about the basics? Timing? Fuel? I know it's getting air, lol Stock or modified/aftermarket intake bellows? MAF?

I'll look more into it when I get more time. It helps me out too, planning my builds.

I have a plane to catch! Leaving the sandbox, YAY lol

 

I don't think it locks up on wot. It is a Yank SS3600 stall. No MAF. Custom 3 1/2" aluminum tube intake. No chance that the intake is collapsing. We will adjust the fuel and timing tables this Saturday on the dyno.

 

converter should lock up at WOT at a given programmed input. TCC lockup threshold in the chip. At the track i ran better with it unlocked so i make the threshold like 120 mph where i will never hit in the 1/4.

On the dyno i locked it up at 60mph to get solid power readings on the dyno. without it locked up, the numbers were down 10-20whp/tq, and thats on a stock motor.

87 TA had his car dynoed with a big 4500 stall i believe unlocked and it made 37x whp... Car runs high 10's at 125mph so its more like 430-450whp but the open converter killed power numbers on the dyno

 

I think Kevin has it programmed to lock up at 65mph. However is the clutch in the torque converter strong enough to hold the power at WOT?

 

i would assume so. I ran mine locked up for years and when i had it rebuilt/restalled EDGE told me my clutch looked good

 

Try using a manual lockup switch. Make a pull with it on and a pull with it off.

 

AFAIK, the strength issue would only matter when it was "locking up", like slipping a manual clutch. Once it is actually locked up I don't think power is an issue... So I'd say lock it up before you go to WOT then you don't have to worry about it.

 

I remember reading years back about jumping two ALDL ports to force the TCC to lock up. Which ports, anyone remember? I am very interested in this as we can't get my ECM to lock the TCC regardless of what we tell it, and I only want to do it for one dyno pull, so building a switch is overkill.

 

What lifters do you have? They could be "pumping up" at high RPM causing valves to remain slightly open, reducing cylinder pressure.

 

The 2nd design factory lifters. Preload is at 1/4 turn.

 

I went over to Dyno Don's shop today and we researched the torque converter lockup issue. There are 4 things that are required in order for the converter to lockup.

1. The proper hydraulic pressure pressure in the transmission to activate the lock up feature of the converter. Couple of mechanical things in the transmission have to happen. Can't remember the terms.

2. The CTS has to be up to the minimum temperature as set in the ECM tables. This can adjusted in the tables.

3. The VSS signal has to be up to the minimum set in the ECM tables. Again this can be adjusted in the tables.

4. Last but not least is the TPS signal. This one is in the program and cannot be adjusted as far as I know. So what ever percentage it is set at is what it is. I would think at anything approaching WOT and the lock up feature would be released.

However as Gunner823 pointed out the TCC signal is at the ALDL plug. It happens to be pin F. So if one were to ground the TCC signal the converter would lock up and bypass the ECM. So that is what I'm going to do in preparation for Saturday's dyno pull. I will have a toggle switch connected to pins A and F so that at the proper time we can lock up the torque converter.

Also Dyno Don has made up a special governor that will prevent a downshift from 3rd to 2nd gear in the rpm range we want to start the dyno run. We will install it this Friday. So we should get some good dyno pulls.

 

thats weird, my 89 6E mask has a TCC lockup prevention threshold, meaning at all speeds below that mph specification, the converter is open. I set it to 60 on the dyno to keep it locked adn to get best accurate readings from the dyno. It makes a difference

 

"my 89 6E mask has a TCC lockup prevention threshold".

So does mine and it is currently set at 65mph. However there is also a converter lockup mph and unlock mph. Mine is currently set at 43 and 38 respectively and the car does so.

Here are my thoughts on the subject. IMHO the main reason for the torque converter lock up is for gas milage. I also believe when you want to pass and nail the throttle the torque converter unlocks. That is where the TPS signal comes in and over rides all regarding the torque converter lockup. I could be wrong as these are just my thoughts.

Questions? What exactly does the TCC lockup prevention threshold do? As stated above mine is set at 65mph but it does lockup at 43mph. Will the TPS signal over ride the lock up?

 

I'm thinking it will, based on what we tried to set the threshold levels to on my car. The way my tuner explained it, there didn't seem to be a way to get around the WOT threshold for unlocking. No matter what speed/throttle values were input, at WOT it unlocked.

 

well you can get around that threshold.

The locking and unlocking is controlled by the TPS and mph speeds like said above. these are the TCC high gear/low gear highspeed/lowspeed limits. I have mine set to like 30 unlock and 35 lock for my low speed high gear (overdrive) setup to help keep the engine rpms down when slowly goin up hills. If i'm goin slow, the converter is open and rpms are way up. that will burn up the trans. So i set it to lock up earlier and stay locked.

there are other settings such as high speed lock/unlock for both low and high gear. Not sure what those do. To control wot lockup, you mess with TCC unlock prevention threshold.

That function is designed to keep the converter locked at WOT no matter what. Its proven, go try it on a higher stalled auto car. YOu can feel, hear and see it locking up at w/e rpm you set it at. I've tried 65mph, 70, 90, and 110+ at the track and keeping it unlocked the whole time provided the best ET's and MPH.

Go out on the street and set it to 65mph and go WOT. it iwill lockup soon as you hit 65mph. You will feel the car lug down and see rpms drop. Converter is not slipping no more Its crazy because on a dyno more power is seen at the tires with the converter locked but that doesnt mean track times will improve with it locked.

 

Our scanner does have an LED that shows when the TCC is locked. So it would not be hard to find out. No matter what we can get around it all with the A-F jumper on the ALDL plug. By the way I'm going down to Dyno Don's tomorrow and I will run the test with my scanner as it does have the TCC lock up code in it and see what it does.

So for the track I should have the TCC threshold set for say 115mph for best times?

When I have the 4L60E installed I won't have these problems. It has a dyno mode and two sets of shift patterns A&B. I can have one setup for the street and one for the track. Just ordered the upgraded parts from Pro Built. But in the mean time. Hahaha.

 

No.

I know for a fact my 86 with the $32 would lock up the converter in the 80MPH range. I had a few chips, one with that obviously changed, and the car was slower. It was always faster when the converter locked... RPM would drop and I'd pick up a solid 2MPH at the traps. Every time. But you do need to pick the right spot to have that happen or the RPM drop and resultant power drop will hurt.

 

Orr89, you are getting better numbers on the dyno when the trans is locked up because you are loosing the slip in the converter and not creating waste heat in the trans fluid. (Obviously.) It also doesn't bog down on the dyno because of the mass you are accelerating. On the dyno, it is only the drive train. On the track it is the whole car. Looser converter cars tend to run faster (same setup, changing only converter) as you have found by track testing.

 

depends on your setup but my car ran best with converter open

 

"I know for a fact my 86 with the $32 would lock up the converter in the 80MPH range."

Madmax was that at WOT?

 

Absolutely. Terminal Island/Brotherhood.

 

I'm curious to know what kind of numbers you would put to the wheels through a T-56....

Have you ever thought about converting it? It's a fairly easy swap...

 

Ok just got back from Dyno Don's. Yes the converter does remain locked above 65mph at wide open throttle in my case. I tried it in both 4th gear and 3rd gear. So as was stated the setting of the threshold mph appears to be the key and mine is currently set at 65mph. I will get with Kevin tomorrow and see about lowering it to maybe 60mph or so for the dyno run or even lower if need be.

With a T56 maybe add 5% to the rwhp numbers. So if I'm putting down 350rwhp that would be around 372 with an M6. We will find out tomorrow if I can get past that pesky 350rwhp mark.

Converting to a T56 is somewhat involved. Maybe like $3000-$4000 dollars. If I were to do it I like the 5 speed version.

 

Could we get an update on what all was changed since last run? You redoing the exhaust right? And a improved tune?

 

Yes. On the last run when I broke the driveshaft we had two half way decent pulls searching for the correct program for the Ostrich. One was 346rwhp and the other was 345rwhp and on that one the driveshaft snapped.

So the things that are different will be the slightly upgraded exhaust, tuning, transmission governor and a different dyno. I have temporary filler pieces installed in place of the cats. Remember one cat was bad. Also we have 2 3/4" exhaust all the way to the wye. Before there were 2 1/2" sections between the cats and the wye. With the new transmission governor I hope we can start the dyno pull at a much lower rpm. It would downshift to 2nd before.

Also I don't thing we will take it up past say 6100rpm. From there I can get a good feel for A/F ratio in the higher rpms.

 

If you are switching dyno's, your new numbers wont mean as much because you are changing a very important constant in this experiment..... Every dyno outputs differently.

 

Did you not do the TB bypass in the picture on page 3? Can't imagine needing the coolant running through there in California.

 

WHAT!!!!????

 

Reid. There is no throttle body heating system with the AS&M throttle body. So yes it is by passed. What you see is the hose for the PVC, the hose to the cannistor and the wires to the TPS. The shinney arc thing is a light reflection off the SLP runner which one could mistake for a hose.

Yes on the dyno. We have run cars back to back on both dynos and maybe there is a 5 to 10 horsepower difference. We are mainly using the dyno as a tuning tool. The real test will be at the track and that will be on May 26. This is the final phase in getting the car ready. We installed the front brake lock and right rear air bag yesterday.

Just hoping I can get into the 12.4's. Then with the 4l60E I should be able to pick up .15 sec and that would put me into the 12.2's.

 

Awaiting results...

 

The results have been posted on a new thread. Here is the link.

https://www.thirdgen.org/forums/tpi/...ml#post3749977

 

This is fabrication at its best!

 

Old thread, but awesome useful info here guys. How did this compare to the cut/welded accel base and custom long runners you made around that time? I'm assuming you didn't use the first base and plenum due to emissions compliance?