Hey yall...I am currently running a turbonetics single turbo in my Z, controlled by a Utec, which Is set up for drift...I am making the transformation into a roadrace car, and I cannot stand the power delivery/ part throttle choppy-ness of this combo...Im thinking a super charger is the way to go...anyone run a supercharger for this application?...Im not looking for an obscene amount of power, just something smooth and part-throttle friendly...sorry for the long post, thanks for your help!

 

stillen roots style s/c should do the trick. immediate power where yiou need it.

 

I'm very happy with my JWT twins. Almost no lag, instant boost. 363 rwhp, 347 lb-fts. Over 300 lb-fts from 2600-6500 rpms.

And yes, I road course my G

 

As the old golf saying (paraphrased for road racing) saying goes, "Build the engine for flash, build the suspension for cash."

 

there is a guy on g35 frenzy his name is brando he has a vortech s/c g you may want to talk to him he tracks it alot and its a very fast car.

 

I would say that the Turbo will be the best bet depending on your tire
The S/c is wonderful for brute torque and exit speed, IF you have the tire to support its grunt.
At least with the turbo you have that lag, which is easier to control.
I am just saying depending on your level of experience and tire.

Just my .02..
Don't want you spinning out a ton

 

Do you really need to switch set-ups? Cant you just tune your ST down a bit, get better piping, and do throttle-control mods?

 

As for tracking these cars on the roadcourse, I have my fair share of track days, but I would suggest talking to the experts in the field of tracking a forced inducted 350Z or G35, and those experts would be the gents over at Relentless Autosports. I think they have pretty much tried it all and have it pretty well figured out. You can see their achievements in the Time Attacks

 

The positive displacement blowers (Eaton, Roots, Stillen) are very good 'down low' but trail off as you raise the revs. They are pretty much all done by 3,000 rpms. The SC's using centrifugal (Vortech, ATI Procharger) spool up are much better high up in the revs where you tend to live on a road racing circuit, but like a turbo are a bit "lazy" until they get up there. All SC's are belt driven and thus have a parasitic power loss as a consequence (figure 50 hp +-). The immediacy of response to the throttle with an SC is very nice for fine control, and thus elimination of lag makes it easier to get on it early and hard on corner exit with more confidence than a turbo, especially if it falls out of boost into or through the corner. A twin lobed rotor lyshholm or whipple type SC has the best delivery curve of power and torque, giving more power like a turbo but early in the curve like a Roots blower, but so far nobody has done one for our cars, and sorting out the fuel system etc is part of the challenge there. And they are expensive. In general the SC is cheaper and less complex than the turbo. Turbos have a lot of "plumbing" and heat management considerations. Both will require an intercooler.

To get the lag issue under control with a turbo set up you typically will want small twins for a road racer, as they will spool up more quickly with less exhaust flow than a big single or larger twins. The JWT 530 BBs are very good in that respect on stock internals. If you build the motor, rods-pistons-cams then you can go with the larger JWT 700 BB units, but that makes the car a monster for street use. Manageable with a driver that knows what they are doing, but you will need to have some real attention paid to the clutch and flywheel to handle the power and still be streetable. Three disc carbon is probably the way to go. I have done SC, the 530 and the 700. If you want to drive it on the street a lot, but not build the motor, then the 530 turbos is something worth looking into.

But....to go fast on the track the real returns will be in the suspension and braking work, not the motor.

 

Spoken by the MAN WHO KNOWS!!!!

 

we've had great success with the JWT TT setups on a couple of road race cars/customers that we have.

I even have a customer with a STOCK BLOCK g35c on JWT TTs and he's gone through almost every event this season with no issues whatsoever.

google= " watkins glen g35 " on google videos to see a run with the camera mounted up front on the grill.

 

^+1 on everything he posted. Start with your suspension & brake system, and re-learn how your Z handles after each mod. But keep in mind, it does not matter how your Z handles or how much power it has -- it's still the "nut" behind the wheel that probably will require the most improvement if you want your car to go faster & safer.

 

*****... can I call you *****?

I think most of the advice given already is pretty spot-on... IF you already have the fundamentals of road course, high-speed driving down pretty well. If not, and you're just starting out, why not put the motor back to stock, get the fundamentals down... use the money to learn the car as is, or do the suspension first... then revisit FI later. I know it's probably next to impossible to go from the power and glory of FI to NA... but I suggest at least considering it. Again... that's IF you don't have much road course experience.

 

I was going to ask this same question, what about Greddy TT for road courses?

 

I agree pretty much with what everybody is saying. A small turbo kit like the JWT 530bb kit with a good tune can behave much like a Stillen SC. Both generate a lot of heat but the TT kit will have more head room to play with down the road power wise, and you don't have to worry about breaking belts. I would suggest starting with the stock motor and JWT 530bb kit, then when you are ready, build the motor and turn the boost up on the 530s. Then when you out-grow that, the upgrade to the 700 or even 850bb kit is an easy one. And if you are up for it and are just starting out, maybe try a few events NA before jumping to the 530bb kit.

If there was a more efficient Whipple type blower that produced less heat and more power then I may choose that over the TT setup, but there isn't for now so my opinion stands with JWT TT kits as the best option.

 

Thanks for all yall's help...I've got a good amount of roadcourse racing in my STi under my belt, and have attended two driving schools (One being Bondurant's 4 day school, where I improved so much it was incredible), My Z is my track ****, and yall's suggestions have been very helpfull, thanks!!!

 

I wouldn't totally discount the Supercharger route..

For tighter courses they can keep up with their advantage of immediate boost. I have driven both Supercharger and Turbo and they both take a different driving style. Going from a Supercharger to Turbo you have to learn to feed the throttle before you really need it and the reverse for Turbo to Super route. Only thing nice about the Supercharger route is if you miss a shift and get the wrong gear or bog it you still have boost. Guess it depends on how much you want to spend and how much hp you need also...

Also from what I have seem at the track, it seems the higher hp Turbo cars break more often or have more issues than the straight bolt-on supercharger kits. Don't know if this is a tuning issue or what?

 

It really depends on the turbo you choose. Like others have said, there is very little/no lag with the smaller turbos like the JWT 530's. There are some heat issues with any F/I system, and roger22 is right, there are certainly more maintenance issues the higher HP you are going.

However, like Eagle1 (and others) have said, suspension and wheels makes more difference. I was suprised at what a huge difference there was when I went to R-compounds!

Dave

 

I took my awesome (on the street / 500 rwhp) APS twin setup off and am happier, learning more AND faster now that I have no choice but to carry speed through a turn

 

Either is fine and takes a different style. I really don't have anything to add to what Eagle has said so well. I can only add my opinion.

Having both setups on the same model cars I personally like the roots style S/C use if it is set up to match the rev range of the engine and track use. The throttle response is the same as if N/A, just more of it. There is less power available and does limit the ceiling you can produce. I will say the Turbo setup gave the car more top in, and lag was minimal, but it was there. I had faster times on tighter tracks with slow turns with the S/C, and big tracks with long straights the Turbo was a bit quicker. I still enjoy the S/C more though on the big tracks.

But back to what others have said, detune the engine a bit, and work on the chassis, suspension, and brakes.