theres only one real way to do this ... ................higher compression between 9:1 and 9:5 with good fuel
If the leader diff gears are way out of yur price range you could always change to an NA Subframe with the higher NA Diff ratio. But then you will need a Tailshaft as well
Yeah, I guess I need to work on getting into the boost range before launch then before complaining about my 60' times then Well what about when not launching at any revs? Just taking off from idle?
I think you should just keep the initial depression of the accelerator as short as possible while you have your foot planted hard on the brake. 4000 revs <1 sec before launch while your foot is on the brake will let you launch on boost pretty well. Cause you dont have a Hi stall converter try to keep the hi rev start short and anticpate the light. Its difficult without the right stuff on the car.
Here is a no bs bang for buck. Buy Drokks ic's. Twin afm with safc. FPR, adjustable. Malpassi, sard nismo whatever. Port your stock dumps (pmacks car went slower with n-powers) Udp, don't worry about the others 3200rpm stall convertor, you will loose response around town. Stock convertor won't let you build enough boost without pushing the car through the brake. Would be nice but not 100% required. These few simple cheap mods will help a huge ammount and cost sfa. Fix your fuel pump first, then bang in some more boost.
Prob upper limit for a stock engine is 16-17 PSI. Even of the block could take more the Turbos dont work too well after that. Reason more people dont run 17 psi, is the injectors max out at approx 14psi. An adjustable regulator will let you up the fuel pressure and get more fuel without bigger injectors.
Pm drokk about the ic's, not sure what he wants for them. There is alot of contention about udp's on the vg, but no facts to say anything. A v6 engine, especially the vg with it's oddball crankshaft configuration, has a very stout, short crankshaft that presents very few problems with udp's. With all the above mods, 16psi+ won't be an issue with a properly setup safc. It is not the best thing out there, but you can pick them up for a couple hundred and do exactly what they are supposed to. Some hate them, some love them. A hell of alot cheaper than nistune or any other option really. For basic correction, which is all you need, perfect.
do you have adjustable struts? try softening the rears to dump the arse-end at take-off. when you rev up the converter on launch it'll help keep traction. oh chuck your spare wheel/jack etc and back seat too when you're at the strip. for intake improvements, this Autospeed article is a good read. less restrictive (not bigger) intake, higher compression ratio, all that will give you better off-boost performance by making our engine more efficient and spooling your turbos quicker.
Softening the rear of an irs setup doesn't help launch, as the car squats the tyres contact patch is reduced.
my mistake. must be only good for solid axles then if kieren isnt breaking traction at all even gassing the stall converter, it'll help break traction a bit and get it on boost with a bit of wheelspin. or maybe thats more effective with manuals only?
im in 2 minds about tuneagent dumps, on my stock setup i did think i was reaching full boost earlier, but with the big turbo wheels they are a load of shite . this can be seen from a design point but also in practice . actuators have to be wound up hugely to reach desired boost levels which i belive is because of a massive pressure build up in the poxy primary pipe on a turbo that is already struggling with a tiny 4 bolt flange. i havent been able to read all of the other posts as this is being done on the ps3
as i said i havent been able to read the other posts as ithis is being done on the ps3 so ihope it hasnt been covered. if i was looking for off boost performance , the big gains are in auto cams, na or leader diff gears, no boost leaks and a tune with alot of low rpm ignition advance
They reckon the quickest way to launch is with about 10% wheelspin. But you would be better off leaning on the convertor as hard as you can without pushing the car to build boost rather than fiddling with suspension too much. I doubt keiren was doing this, but watch out next time he takes it out With our na, I was launching at 3200rpm(stall convertor) and getting similar 60's to the tt guys. Ideally you want to launch about 100rpm under peak torque, so for an na that would be around 4000rpm.
Well I never looked at the tacho, but from what I heard I was only bringing it up to about 2-2.5k on the brakes. Quicker times here we come but at least now I have something to practise. So, from what I now understand, the only real way of increasing performance on the street before I start making boost is losing weight, higher compression, UDP, leader gears...
Yep you are definately right on all accounts Rob. the Npower split dumps are far from the best out there. Like i said in my earlier post, i'll be getting better dumps in the near future. And one thing, i'm not sure where this $300 figure came from.... The dump pipes alone are only $250 per set... Regarding the size, i compared the exhause wheel on the turbo to the exhaust pipe on the split dump and they're actually just about the same size, so there's no obvious restriction of flow from the turbo when it his the dumps. I just want to make quite clear to everybody out there that there are much better designed dumps around for big HP, but i'm just expressing my experiences from going from stock as a rock turbos to upgraded turbos using the same cheap dump pipes - and they can clearly handle bigger HP. - at the same time, i'm sure if i had better designed (and much more expensive) dumps on there with my exact same setup, i'd most definately be reaching even higher HP. But that's another task for another day. I feel that i'm getting a bit off topic though, and making this thread all about dumps, which isn't quite where this thread was heading....
I guess that I have to ask the question " Is drag racing what you have the car for"? Surely having a car that is reliable, fast and can hold the normal roads is more important than beating other 300zxs over 400mtres once in a while. It seems to me to be a high cost to achieve this. I am building a car specifically for track racing or more specifically lap times, this car will not be registered on Qld roads which will remove a lot of restrictions that will normally limit the cars performance. Yes I understand not everyone is in my position, but you can spend a lot of cash trying to acheive performance and then find that the car is no longer insurable
