Jump to content
SAU Community

Recommended Posts

broke my drag racing virginity last night at Willowbank, QLD

car:

r32 gtst

rb20det automatic

155rwkw

time:

14.714

98mph

60' 2.503

The 2 things that were hurting me:

takeoff with the auto and rb25 turbo was hard. stomped on accelerator and brake and pulled up handbrake, but couldn't build positive manifold pressure as it has an rb25 turbo that's slightly too big to get boost at that load

i run out of power about 6000rpm as it gets too rich, so the auto changing at 7500rpm wasn't helping.. would ideally have changed at 6500rpm of there abouts

any ideas to improve?

I would have thought that with a 60' time of 2.2ish i could get mt ET down to 14.4ish with just that?

cheers,

Warren

Link to comment
https://www.sau.com.au/forums/topic/126090-first-time-at-the-drags/
Share on other sites

I would say thats about right hey...

The 60 footer is pretty ghey but there is not much you can do with the factory stall on autos unless you get it restalled...

I would probably try and do kinda a line lock and before it starts to build up decent positive pressure in the inlet release the brake and kinda skid off the mark...may sound stupid, but i would give it a go...

shifting manually doesn't make a difference as it still changes are redline..

when you put your foot down, it activates the "power" function automatically and it can't be turned off when you're flat out...

and as i have an rb25 turbo, the exhaust wheel is slightly too big to make boost when stalling the auto at 1800rpm.. I would say its about -2psi (relative to atmospheric) at that load, so its quite close to making positive manifold pressure, but not quite there

like I said in the other one 98 mph is good for a high 13 with a better 60ft and a few decent shifts.

If you are holding consistant revs to stall you might find that you can't get positive boost. To hold the rpm at that level there isn't engough load to have the throttle opening enough for boost.

So perhaps just stomping the accellerator down is a better approach and forgetting the handbrake thing for now since you don't have a enough stall speed. having a snick of wheel spin off the line will get the turbo into boost otherwise you are bogging down.

shifting manually doesn't make a difference as it still changes are redline..

when you put your foot down, it activates the "power" function automatically and it can't be turned off when you're flat out...

and as i have an rb25 turbo, the exhaust wheel is slightly too big to make boost when stalling the auto at 1800rpm.. I would say its about -2psi (relative to atmospheric) at that load, so its quite close to making positive manifold pressure, but not quite there

could you just ease up off the pedal in a gear to make it down shift and then floor it again. if the previous rpm was around 80%+ then the car should just hold the next gear without down shifting.

shifting manually doesn't make a difference as it still changes are redline..

when you put your foot down, it activates the "power" function automatically and it can't be turned off when you're flat out...

and as i have an rb25 turbo, the exhaust wheel is slightly too big to make boost when stalling the auto at 1800rpm.. I would say its about -2psi (relative to atmospheric) at that load, so its quite close to making positive manifold pressure, but not quite there

If you can make a little boost you will find the stall speed goes up, if you can get the stall rpm up you will make more boost (Catch 22).

What you need is a bit more ignition advance around 1800 rpm.

What are you using to tune it with? SAFC? Rechip? Power FC?

If you have an SAFC, try leaning it out around 1,800 rpm. That will give it some ignition advance at the same time. If you then get some pre-ignition with 98 ron, try Shell Optimax Extreme 100 ron. That will avoid the pre-ignition problem.

Once you get some boost (torque) you will find the torque converter stall rpm will go up. Even as little as 100 rpm might be enough to break the circle.

:( cheers :pirate:

Edited by Sydneykid

gary - stock ECU (i know, i know, its my next engine mod.. but goign the shift kit first)

don't have the snow mode button, only the "hold" which i believe is the same thing - will try the 2nd-gear-takeoff-then-into-first method before i go next

neutral dump? i'm not an idiot...

no point buying smaller tyres as it defeats the purpose of my drive in, drive away approach

oh, and i ran it on optimax extreme, like i do everyday :D

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Update 3: Hi all It's been a while. Quite a lot of things happened in the meantime, among other things the car is (almost) back together and ready to be started again. Things that I fixed or changed: Full turbo removal, fitting back the OEM turbo oil hardlines. Had to do quite a bit of research and parts shopping to get every last piece that I need and make it work with the GT2860 turbos, but it does work and is not hard to do. Proves that the previous owner(s) just did not want to. While I was there I set the preload for the wastegates to 0,9bar to hopefully make it easier for the tuner to hit the 370hp I need for the legal inspections that will follow later on. Boost can always go up if necessary. Fitted a AN10 line from the catch can to the intake hose to make the catchcan and hopefully the cam covers a slight vacuum to have less restrictive oil returns from the head and not have mud build up as harshly in the lines and catch can. Removed the entire front interior just shy of the dashboard itself to clean up some of the absolutely horrendous wiring, (hopefully) fix the bumpy tacho and put in LED bulbs while I was there. Also put in bulbs where there was none before, like the airbag one. I also used that chance to remove the LED rpm gauge on the steering column, which was also wired in absolute horror show fashion. Moved the 4in1 Prosport gauge from sitting in front of the OEM oil pressure gauge to the center console vents, I used a 3D printed vent piece to hold that gauge there. The HKB steering wheel boss was likely on incorrectly as I sometimes noticed the indicator reset being uneven for left vs. right. In the meantime also installed an airbag delete resistor, as one should. Installed Cube Speed premium short shifter. Feels pretty nice, hope it'll work great too when I actually get to drive. Also put on a fancy Dragon Ball shift knob, cause why not. My buddy was kind enough to weld the rust hole in the back, it was basically rusted through in the lowermost corner of the passenger side trunk area where the wheel arch, trunk panel and rear quarter all meet. Obviously there is still a lot of crustiness in various areas but as long as it's not rusted out I'll just treat and isolate the corrosion and pretend it's not there. Also had to put down a new ground wire for the rear subframe as the original one was BARELY there. Probably a bit controversial depending on who you ask about this... but I ended up just covering the crack in the side of the engine block, the one above the oil feed, with JB Weld. I used a generous amount and roughed up the whole area with a Dremel before, so I hope this will hold the coolant where it should be for the foreseeable future. Did a cam cover gasket job as the half moons were a bit leaky, and there too one could see the people who worked on this car before me were absolute tools. The same half moons were probably used like 3 times without even cleaning the old RTV off. Dremeled out the inside of the flange where the turbine housing mates onto the exhaust manifolds so the diameter matches, as the OEM exhaust manifolds are even narrower than the turbine housings as we all know. Even if this doesn't do much, I had them out anyways, so can't harm. Ideally one would port-match both the turbo and the manifold to the gasket size but I really didn't feel up to disassembling the turbine housings. Wrapped turbo outlet dumps in heat wrap band. Will do the frontpipe again as well as now the oil leak which promted me to tear apart half the engine in the first place is hopefully fixed. Fitted an ATI super damper to get rid of the worn old harmonic balancer. Surely one of the easiest and most worth to do mods. But torquing that ARP bolt to spec was a bitch without being able to lock the flywheel. Did some minor adjustments in the ECU tables to change some things I didn't like, like the launch control that was ALWAYS active. Treated rusty spots and surface corrosion on places I could get to and on many spots under the car, not pretty or ideal but good enough for now. Removed the N1 rear spats and the carbon surrounding for the tailpipe to put them back on with new adhesive as the old one was lifting in many spots, not pretty. Took out the passenger rear lamp housing... what do you know. Amateur work screwed me again here as they were glued in hard and removing it took a lot of force, so I broke one of the housing bolts off. And when removing the adhesive from the chassis the paint came right off too. Thankfully all the damaged area won't be visible later, but whoever did the very limited bodywork on this car needs to have their limbs chopped off piece by piece.   Quite a list if I do say so myself, but a lot of time was spent just discovering new shit that is wrong with the car and finding a solution or parts to fix it. My last problem that I now have the headache of dealing with is that the exhaust studs on the turbo outlets are M10x1.25 threaded, but the previous owner already put on regular M10 nuts so the threads are... weird. I only found this out the hard way. So now I will just try if I can in any way fit the front pipe regardless, if not I'll have to redo the studs with the turbos installed. Lesson learned for the future: Redo ALL studs you put your hands on, especially if they are old and the previous owners were inept maniacs. Thanks for reading if you did, will update when the engine runs again. Hope nothing breaks or leaks and I can do a test drive.
    • No those pads are DBA too  but they have colors too. I look at the and imo the green "street" are the best.
    • I’m not sure what happened I told them about sonic tunes free OTS tune and the next the I know .. I was booted..   To funny 
    • Yea - I mean I've seen my fuel pump which is decades old and uh, while I'm not saying this with real knowledge... but I sure get the ick at using anything in the fuel system that produced the state of that pump. Many years ago I went through multiple pumps (and strainers) before I dropped the tank to clean it out with extreme violence. I'm talking the car would do maybe 50km before coming to a halt, which resulted in me cleaning out the filter with some brake cleaner and going on my way. None of my stuff ever looked like what came out of your fuel tank. I don't think I'd be happy with it unless every single component was replaced (or at least checked/cleaned/confirmed to be clean here).
×
×
  • Create New...