rx7tt95

For the Power FC guys, there's a "PRO" chip available ONLY for the first gen Power FC (3-pin boost terminal) which is effectively a 2-step and allows you to set your launch rpm. It's a snap-in replacement for the existing chip. I believe the 2nd gen PFC's have their processors mounted permanently.

Roy Johnson Jr

A small shot of nitrous would definitely spool a big turbo quickly. However, I would still like to know what method others have found to build boost at the line and be somewhat safe and effective and how they set it up.

fdracer

w/ a stick the only way to build boost off the line w/o nitrous is either w/ a 2-step or anti-lag.

Roy Johnson Jr

Do both of those methods rely on igniting raw fuel in the exhaust side of the turbo to build boost?

pluto

why is there so much interest with launching with boost lately?

Roy Johnson Jr

Because I'm ready to move out of the low 7s and into the 6s and I know leaving with boost at the line is the key! Leave the line with it rather than waiting for it to build after the clock has started.

I've been searching for a long time.

fdracer

only anti-lag does. but the 2 step isn't all too healthy for your motor either.

Roy Johnson Jr

Well, Pluto has joined in the discussion with us, maybe he can be of some help!

pluto

I prefer to stay out of this thread since both the anti-lag and 2-step aren't healthy to the engine. unless you plan to rebuild your engine once a year, I wouldn't recommend using either of those methods. Both will cause side seals to expand and stick pre-maturely and requires more tear-down than normal to maintain the engine. I have been using anti-lag for years. its awesome launching at 20+psi of boost and getting low 1.4's on ET streets even with a lightweight flywheel but I wouldn't do it on a daily car.



just my .02

Roy Johnson Jr

So, I guess that means I'm back to slipping the clutch or trying to use nitrous off the line? I was really hoping to build boost at the line. Is there any other method?

pluto

What I used to do at the beginning of drag racing was to keep the rpm at around 4krpm, and when it turns yellow, I floor it until it reaches 7krpm and dump the clutch. You should be able to get 3-4psi from free reving from 4k to 7k. I was still able to get low 1.60s doing it that way.

Roy Johnson Jr

Thanks for that tip! I'm still disheartened about not being able to build a lot of boost at the line though.

How tricky is it to use nitrous?

fdracer

as long as you know how to tune it's very easy. you can spray outta the hole and set it to turn off at a predetermined boost level. or you can even spray the whole way down the track, it even makes your turbo more effecient.

Roy Johnson Jr

Where is the best place to locate the jet on a 7?

APEXL8T

I do same as Steve ..here is a video I have of the 1st time I figured this out. However I am revving up and down later I sat around 4-5000.Stock motor and missed fourth . These are street tires...not drags as street dot. 1.78 60'

http://www.nopistons.com/forums/inde...md=si&img=1932

Erdin

How would you set up the msd in order to build up boost off the line useing the two step method. would you have to do anthing regarding when the trailing or leading fires up.

thanks

Erdin

MichaelB145

I pulled a 1.63 by just dropping the clutch at 6100 RPM. I had used both Street ET's and BFG G-force Drag radials. The key is a soft suspension in the rear....the car must squat! With a 2 step hooked up, I should be in the 1.5's.

Nihilanthic

If its a dedicated drag car, or you just street drive and drag, theres really no reason to not get an automatic with a stalled converter that stalls to the RPM where the turbo is mostly or totally spooled up. You can leave off the line fully spooled up (power brake it), and on street driving the turbo is always there.

You'll also lower ETs with the faster shifting, and be easier on your rear end.

And well, yeah, if you want a manual for fun or if you track or autocross it a two-step works great. Just make sure you get some real DRs (and lower the pressure at the track!) and put in stiff bushings, good shocks, but not too stiff springs.

LUPE

I pulled 1.50's by just dropping the clutch. I could probably cut a 1.49 if I heated my tired up more.

I'm going with a stalled automatic with a brake.......

mmonaco

Steve,
How can an AUX rev limiter/ 2 step be unsafe and cause a motor frequent rebuilds? Your saying with a fuel or ignition cut that it will expand the side seals, and allow it to stick prematurely? For a side seal corner seal to stick you need extravagant amounts of heat, to allow the springs to fail, but with a cut on fuel or ignition, temps shouldn’t rise unless pre ignition of fuel is occurring. I can’t see how a 2 step has a major negative effect on a motor. Please enlighten me!

Thanks
Marc

Nihilanthic

There any reason to go with a transbrake instead of just powerbraking? Im not questioning you, I honestly dont know.

LUPE

I'll be using a 6500 stall on the trans brake. Trying to use your normal brakes at this RPM w/ boost you'll be spinning the tires. Trans brake keeps the tires from spinning while loading the motor up.

crispeed

It wall also keep you from pushing the front wheels when trying to power brake. The trans brake also acts like a clutch would in a manual tranny for launching purposes. It takes most of the load off the tranny components while trying to get the stall up on rpm. The trans brake basically is like a neutral drop without any of the ill effects. It does that by locking reverse and 1st gear together when activated.
Lupe make sure and install a tranny temp gauge. It's important not to get the oil temp too hot while on the stall/trans brake during launch because you would not have a tranny left for the rest of the 1/4.

LUPE

I'll be sure and get a gauge! Thanks......

Anyone know how much boost a person can make by just stalling and braking a automatic with a 6500rpm stall? I get full boost normally by 5k rpm.

crispeed

FULL BOOST
Normaly you can take advantage of the automatic and use a huge turbine section on the turbo and reap all the benefits of doing so.
You should contact Mike Lowe from Low performance here in Florida. Mike been running an auto on his 1st gen for many years now. He competes in the outlaw/modified class and runs consistent low 8's with an auto behind his 13B.