Wicked69

I went threw 2 TH400's this year and am now trying my hand at a powerglide. The powerglide was built by someone completely different and have been told it has been built to handle 900 horsepower.

Here is the issue I am having. The guy who built my TH400 said the reason I kept tearing it up was because I would pre-stage using the foot brake and bump into stage and then hit the transbrake. I would was around 3k when I would hit the transbrake and that seemed to help build boost.

Now the guy who built my PG also tells me that I shouldn't try and build some boost with the foot brake first but to set the stage beems and then hit the transbrake from idle and build the boost.

It seems to me when I watch everyone else that runs a turbo that they are building the initial boost on the footbrake and bumping into the second set of beems, then hitting the transbrake and mashing the throttle to engage the 2 step.

How do I need to be building boost with my PG. I have a transbrake and a MSD 2 step set at 3800? I don't want to screw up another trans but it sure seems as though I need to foot brake some to get it up on boost or I will be sitting there all day trying to build it on the transbrake alone.

Set me straight please with how you guys are doing this and not tearing up the trans.

Cam72aro

iTrader: (28)

This is taken from dville_gt with his mustang. It was from his thread.

footbrake and tbrake activate the 2 step and the boost controller. so if i'm pulling into the lights and i'm on the footbrake my boost controller is putting whatever psi on the gate that i have set for launch, if i choose not to use the tbrake then i just bump into the second light and wait for green and let off the brake, at that point the 2step turns off and the boost controller starts going through it's stages, taking me from 12psi to 20psi. if i choose to use the tbrake then i build up the boost on the footbrake, bump into the second light, grab the tbrake which keeps the 2 brake activate as well as the boost controller, let off the foot brake, and as soon as i see green i let go of the tbrake which turns off the 2 step and starts the controller going through it's stages.

i actually like the footbrake, with the 2 step and controller it is so easy, i roll up, first beam on, mash the brakes, mash the gas, get the boost up, let off the brakes slightly to get into the next beam, then wait for green and let off the brakes, i'm already 100% throttle and the controller takes care of the power management.

Wicked69

It sounds like he is doing exactly what I am doing when using the transbrake. Ie, build boost using the footbrake, bump into the second beam, hit the transbrake to engage the 2step, mash the throttle, let off the transbrake and the 2 step disengages. I don't understand why they think this is killing the transmissions. I am not up on the convertor or tbrake near as long as the other turbo cars, hence why I haven't been able to build boost in the past. If I do it the way I mentioned I can build 12lbs of boost in about 5-6 seconds from the time I start. I didn't think that was that bad. They are acting like that is waaaaaaay toooooo long.

Cam72aro

iTrader: (28)

Everyone does it with the footbrake then t brake. Like you said, it would take a while on just the trans brake alone. I think something else is screwy with your trans. The above is with a glide. Usually it kills the converter if you build too much boost and heat. You might need to get a different builder if you have this problem again, or learn how to build a glide yourself, they are uber easy. I build the one in my s10 a few years back. It went 1.29 60's off the brake with a 250hp shot.

Wicked69

You are right. I may need to learn how. We will see how this glide does. It gets him off the hook I guess but if I don't build 10-12lbs of boost there is no way my car will ever leave on a decent 60ft. That's for sure.

TDMKR496

iTrader: (3)

Do you have a trans temp gauge? When your on the TB it super heats the trans, and if your converter is loose it just makes matters worse. I use a three step to get the exhaust gas hot and help spool up the turbo on the foot brake as I roll into the beams and then once I'm in I put it on the brake and my foot to the floor. Works pretty good.

Wicked69

It's not a loose convertor. It is a PTC that was spec'd for me. Around a 3400. I understand the idea of the transbrake getting everything so hot. What I don't understand is how getting it up on boost using the footbrake first, then hitting the transbrake, how that is hurting the trans. I would think trying to build boost on the transbrake only would be worse.

Only thing I can think of is if the brakes are not good enough and the tires start to spin when you are hitting it. Maybe that is what they are referring to. I don't think that is what is happening but I have disc brakes up front and only stock rear drums in the rear. I guess if the rear tires started to spin prior to hit the tbrake that would screw **** up.

If that is what might be causing it, I can just ad some rear discs.

What 3 step do you have? Is it as easy to wire up as the MSD 2 step? That **** was easy. lol

slow67

iTrader: (2)

Did your clutches look worn like this?

TDMKR496

iTrader: (3)

I have a digital 7, but you can use a three step, the whole idea is to get the exhaust gas hot to spool the turbo.

dville_gt

iTrader: (5)

i've never seen a turbo car roll in and hit the t-brake off idle, everyone rolls in on the footbrake (most with a low limiter triggered by the brake lights), then as soon as they see the second bulb they hit the brake (which activates the high limiter), and let off the footbrake. really makes me question your trans builder.

DHR Darren

iTrader: (1)

If you try it just off of the T-brake you will kill a trans within three passes. You have to build boost via footbraking or with a bump box. You never want to be on the T-brake more than 3-4 seconds max!

98Z28CobraKiller

iTrader: (17)

There is another way. It's called creep control but I think it's even harder on the transmission. Perhaps a transmission guy can chime in. Basically a controller pulses the tbrake solonoid very fast. So you idle into the first beam, get on the transbrake and start building boost. Then you hit the creep control button to roll into the second light. The entire time you are WOT on the tbrake and the 2 step. Nothing makes boost faster.

DHR Darren

iTrader: (1)

AKA bump box

71 chevy

iTrader: (18)

you could also try this

https://ls1tech.com/forums/forced-in...-lag-work.html

71 chevy

iTrader: (18)

also, if you are not racing a series, or class, or person,

dont worry about the light.

Wicked69

Well I just ordered a rear drum to disc conversion and going to ad a line lock. Now I should be able to build boost on the footbrake and then hit the tbrake. They said the issue was my wheels would turn when I would use the foot brake. The wheels moving when I hit the transbrake is what was tearing them up. I didn't know the wheels were moving. I have the original drum brakes.

71 chevy

iTrader: (18)

what was broken in the trans?

Wicked69

Third gear and reverse would start going out at the same time. The first time I ate the pump. Not sure this time. I was offered $350 from someone for it even with it broke so I sold it to off set the cost of the PG.

Here soon, I will also get the bump box. If anyone has a part number for it.

71 chevy

iTrader: (18)

Is it me or do bump box and junkyard 5.3 just not go together? , if you know what I mean.

I would like to see that money spent on forging your engine so you can really get after it.

Phil99vette

iTrader: (11)

2 different ways to do it..

1) Foot brake
You will most probably need 2 limiters, one on the footbrake(brake lights) one on the transbrake, 200 rpm stagger
depending on how fast the combo comes up, roll 3" outside the prestage beam, load the brakes and bring it up on the chip, then roll in to prestage, then to stage. Once its staged grab the transbrake and your good. This setup requires dual brakes to be done correctly. It needs to be hot going onto the final limiter.

2) Use transbrake and a bump box
Brakes dont come into play, roll the car into the pre stage beams, hit the transbrake button. Car will come up on boost and RPMs. Once its on the chip, bump the bump box button and it will pulse the transbrake fluid system, rolling the car into the beams. You never let off the transbrake button until your ready to leave, you have a 2nd button going to a box that will pulse the transbrake.

Ways to spool faster
Advance the cam
more timing
wrap the pipes
carefully tuned A/F
properly sized pre turbo pipes.

I use an NLR solenoid control box but here is another


Foot braking...