Transbrake And True Stall, Way Too High!!

[GNVYUS 1]

Jesus, took the GN out to get used to the Stageright and my tight 3400 Precision is 0 psi boosting around 2800 ( boost gauge sucks at 0-2 psi ) but going past 3600 at 8psi. I stopped after seeing that rpm and KNOW it could've gone further if I stuck my foot in it more.

Wow, I guess I should have specified that I was going to a transbrake and not footbraking it. 3600 rpm + with a TA49 is pretty high, the thing leaves at 3psi like crazy though.
I guess I have room for the bigger PTE turbo's next year. :biggrin:

Any idea what the Transbrake probably adds over foot braking tranny pro's??

BTW, I got both the West Coast and East Coast vendors inside, Bruce's input and Chris's billet drum. Gotta play both fields

 

[Quick6'n'-K.C.]

To be totally honest with you, with the t-brake your gonna roast the tires with that small turbo. Since your car has some head work, and looking at the injector size, a 66mm turbo would be right where you need it.

If you decide to get a larger turbo and the convertor is very loose, a .85 PTE housing would be the best, i have a te45a (66mm) with the .85 and the same convertor with a ball style boost controller... It comes up very fast and the car is a beast even at 5psi of boost.

Its alot easier to change turbos than convertors:biggrin:

If the combo is right, there will be minimal lag

BW

 

[bison]

Looks to me like your converter is just right for your turbo at 2800 at zero. Go to a Precision .85 if you want to slow it a little down low. You will gain everywhere if you launch a
t higher boost levels with the .85. The t-brake is worth something if you have the suspension and tire ready for the hit. You should be able to run low 1.50's if all is good.

 

[GNVYUS 1]

I'm digging how well the TA49 responds on the street but was surprised to see it keep going even at 3600rpm and 8psi. So I called Precision just see what Jack thought and he said that the longer I stay in the transbrake and torque it, the converter will start to push out more fluid and the rpm will keep climbing. So I could have gone higher he said.

It sounds like I need to keep my transbrake torquings to 3 seconds so I need to get into faster. Still learning how to race with this thing.

But I agree, I SHOULD change my turbo and then I'm probably golden with this converter. I also should do the exh housing swap now but I want to see if I can go high 10's first so I've been modding around the turbo all this time. 10.9 I think is the time to beat.

 

[Sal Lubrano]

I am going to offer my advice. I have had a tight and loose converter. If I was at the track and I was looking for my best ET's I would say a tight converter is ideal. Because you will always be foot braking so spool time is not number one to be concerned about. My car rarely sees the track so it is all about having fun on the streets. When I am at a light and I hit the gas I want the turbo to spool fast so I have a looser converter that a track car would. I know the efficiency of my converter sucks in the upper power band but a whole lot more fun to drive. If you are going to have a loose converter make sure you stick with a lock-up otherwise on the freeway the trans oil is going to roast.

 

[Dusty Bradford]

This is the reason guys racing on the pro-trees are swapping to distributors....a reliable 2 step set-up rather than relying on the DIS-4's.

The 2 step will hold a set rpm for launching. What you are seeing is very common with turbo torque converters and transbrakes. As your rpm climbs, so does the boost which increases power, it pushes through the converter which raises the rpm and the boost/hp just keeps climbing. The extra power keeps pushing through the converter. You will eventually get to a spot where the converter will hold but you don't want to stand on it that long. Each second you are on the transbrake, tranny temps increase 50-100 degrees depending on what rpm you are at.

 

[KILL4PEACEUSMC]

Ive been dealing with this for some time with my turbo 400. I never considered going to a Dist. and 2 step, can I still run A/C with a dist?

 

[Dusty Bradford]

Ive been dealing with this for some time with my turbo 400. I never considered going to a Dist. and 2 step, can I still run A/C with a dist?

Never tried it myself. You can do some searching on here. I know this question was asked before but I'm not sure that it was ever answered.

Most guys who are worried about consistent launches are racers.....these same type guys pull off the a/c so changing head gaskets is much easier:biggrin:

 

[KILL4PEACEUSMC]

I understand, I live in Arizona, so I need BOTH!

 

[GNVYUS 1]

I remember someone saying they used the TPS to gauge where to hold it. I tried it and can see how that might work if you were to be conscious of how long you are in the brake.

But the 2 stage makes sense and might be something Eric can do in the chip for us?
For me something around 3200 so I can just lay into it for a few seconds and then slap it.

I'd read a post from the fastest 2G auto DSM ( high 8's now ) say he does the two step and now I see why. This could make it a much more consistent car and if Eric could make it tweakable like the other options in the chip an easy way to tune the launch RPM.