S15 200sx owner

Thanks John! You are a wealth of knowledge on this forum, we all appreciate your input.

Wow!!! What can i say.....Great work and good on you! another one lives again, awesome!

Awesome, Thanks for the run down John! It makes sence to me. So do you think running 9.5-10" wheels all round is quite acceptable then? Is that white car one of yours? Very nice, if so what are the wheel/tire sizes on that?

Oh ok, I am very new to Rear wheel drive race cars (have been running FWD cars) Would it be fine to run 10" front and rear, 275-285 sounds huge for the front? Please can you explain the theroy behind this, I saw someone else mention they prefer same size wheels and tires all round on sports car in another post recently as well. Thanks John, appreciate it.

Thanks for all your comments guys. I am thinking i'll go with something like this 17x9 front with 245-255's and 17x10 rear with 275-285's Jon C, What difference in width is ideal or do you recommend between fronts and rears for circuit racing?

Hey thanks for your comments Dave, you do raise good points, I just remember reading a chart one day that had a list of tire widths to power level. Was just intended to be a general guide. I think it was published by Hoosier or someone. I was just interested as i dont want to end up over tiring the car if i dont need to.

How do i work out what width tires i should run for the horsepower level i will be at? Is there a basic rule of thumb that says X mm for every 100hp or something??

It sure is! See the hubs in that pic appear to be alloy (only the GTR has the alloy ones, GTS's are cast iron) Also see the bolt pattern on the inner CV, it has 6 evenly spaced, where as the GTS's have 3 pairs of 2) So yep that is def GTR, which is the R200 C/LSD, same as what i have.

Hey helix, What sort of numbers is that VL in Auckland making?

They're not too bad are they? I got mine from the US, thought it was quite resonable, what are you comparing the price to?

There must be hundreds of thousands of those mustangs in the US! Who cares if someone puts an RB in ONE! I say good on him! ......I like it! .......But then again, i've always liked pissing off the V8 boys ..........waiting to be flamed.

Hey thanks for the little write up. I get excited when i hear stories about breaking traction in fourth gear @ 65mph!!!! I have bought one for my RB30DET (but have gone with the 1.06ar hot side). I think that it should work very well! Sorry for the slight hijack. Cheers.

OMG! Thet are freakin HUGE! Interesting.... i wonder if they will fit my r32 GTR C/LSD R200 (which appears to have the same big 6 bolt inner CV's as the R230's)

I wouldnt go with the VG30 single turbo, way too small, I run one of those on my Mini circuit racing car, it has a 1370cc engine, makes about 200hp and is not that laggy believe it or not! sorry 260det, no offense eh.

The problem you are describing of not making as much boost in the lower gears is quite common. As there is not much load on the engine and its not making that much exhaust gases to spool the turbo up. In my experience most turbo cars generate a higher boost level with every gear you go up! as the load becomes greater. What you must remenber is that the GT35R is a Ball bearing turbo (which spool up much faster than a plain bearing as in your old T3. I would still go for a GT35R (its a very common turbo for your application) but maybe go with the smallest ex housing of .64 (i think). I would not go smaller than you have already have. If your problem is as bad as you say, you should start looking at the system you are running to supply signal to your wastegate. One thing that you can do is to attach a canister (like a empty aerisol can with a fitting screwed into the end where the spray button goes) "T" it into the signal line that goes from your manifold to the wastegate. This will in effect let the wastegate stayed closed that little bit longer while boost builds rapidly and essentially "overshoots" your normal wastegate pressure, before settling back down to normal presure after a split second or two (this lenght of time of Boost spike can be tuned by the size of the canister) Ie. Bigger = longer, Smaller = Shorter. This little trick essentially fools the system into building boost faster and harder. Also quite useful on the Highway, when you punch the accelerater, gives you a short over boost spike, to get you up and going and then it automatically drops to normal level after a few seconds. Simple but effective, Give it a go and see what happens.

Thats right Mike! theres a few sicko's like me around. There are still plenty of RB30's around NZ & Aussie, and the Aussie built VL Holden Commodores that they came out in. But as NZeder said, there are also now a few people after them, so the price is going up! I have got three of them, that should prob give enough spare parts for now, but will always be on the look out for bargin doner engines. As everyone else has said the freight from NZ/Aussie to the US is the killer, I guess it all about how bad you really want one though eh. Clint T

Go for something modern & ball bearing, the Garrett GT35R seems to be a good size for the RB30, it should spool real well and make lots more power than your old school T3. I will be running RB30 with RB25DE head and have chosen the GT35R after much homework, and have gone with the larger 1.06ar on the exhaust housing, if you want faster spool and if you are SOHC still then go with the .82ar on exhaust side, cant go wrong! http://www.horsepowerinabox.com in Aust have them pretty cheap these days, i got mine from James Thagard in the US (on this forum), worked out well.

Have you done this Richard? I am keen to hear more about your car in regard to chassis, susp mods etc, you seem onto it.

I need to buy two new frame rails for my 72 240z, anyone know of anyone who sells these in Australia? Will need to send to NZ. Cheers.