Just wanted to let you guys know that JWT still says the kits for the G and Z are all done but they're waiting for the CARB cert to come back. I asked if they were expecting to have it for the summer and they said they're not sure. It might be a couple of months according to the tech there. I also asked him if the 420hp dyno they posted on their site was at the flywheel or the wheels since people were saying that it must be at the wheels. He said the dyno posted is not at the wheels. It's at the flywheel!! I was disappointed when I heard that. What do you guys think about this? I asked him what to expect at the wheels from this kit and he just said they're shooting for 400hp to the flywheel so transfer that to the wheels. So that's roughly 335whp? He also said they're not doing ecu reflashes, they have their own standalone for the kit. He wouldn't say what they were using. Only that I should keep watching the website.

 

JWT always lists horsepower at the flywheel so that should be no suprise. It will be interesting to see if they release the standalone on its own.

 

It is not actually a stand alone. It is essentially a piggy back unit. I verified this with Jim Wolf...as in the person...

 

its a piggy back...curious to know which one they use.

Anyone using the Haltech interceptor boxes?

 

The piggyback is of their own design. Clark Steppler at JWT designed and built it.

 

what kit is this your talking about? is it an FI kit? sc or T?

 

JWT Twin Turbo.

 

Well I guess I thought the dyno was at the wheels because some people over at g35driver said they were familiar with the dyno that JWT uses and that if you don't enter the correction values (which most people don't) then the hp will read at the wheels even though it says at the crank on the sheet. So everybody was thinking that was the case.

 

That is ineed the case. Those are in fact rear wheel or technically rear axle numbers as reported by the DynaPack dynamometer. I can write a white paper explaining the whole 'fly-wheel' vs. 'rear-wheel' misconeception, but that'd take up the entire screen.

This may sound contradictory to what the the tech told you JWT, but it sounds to me like he is refering to the 'out of the box' kit at ~6.8 psi (?). It puzzles me why they chose to post the non-stock 8 psi dyno plot on their website. Believe me when I say the JWT is very capable !!! you will all see soon enough.

Hope that helps.

 

No, he clearly told me that the dyno sheet on the website was 8-8.5 psi and measured 420hp at the flywheel and that the kit will not be released at that power. It will be around 6.8 psi and 400hp at the flywheel. He said the reason why they are doing that is because the rods can't take the power past that for a long period of time. I know people have been 12k miles on a bone stock car but that's not considered long period. I guess it's possible the tech doesn't know what he's talking about but I think he may be right about that dyno being at the flywheel. 6.5psi on most of the other kits is around 350whp right?

 

I think you may have misread part of what I said ...

We both agree the stock kit is rated at ~6.8 psi., which begs the question why was the posted dyno plot for the non-standard 8 psi configuration (clearly stated on the plot) on their website. The 6.8 psi configuration will most certainly make less power than the 8 psi trim.

In either case, as such, the 8 psi plot is figured from the 'rear axle'. Unless you spoke to 'Jim' of Jim Wolf yourself ... then you were mislead by a confused 'tech' and that wouldn't have been the very first time. It's all too easy to make that assumption because the dyno software makes the reference to 'FLYWHEEL'. It's a technicality issue, which I would love to get into in another thread. Once again, the DynaPack dynamometer results are derived from the 'rear axle', unless Drivetrain correction (TCF) was used. In nearly all cases, they are almost always left at it's default value of 1.0 (zero correction); JWT did just that.

Again, the results will present themselves shortly!

 

well this all makes sense now and answers the questions we had over the last 2 weeks

APS kit for me

 

This month's SportZ magazine's suppose to have an excellent write up for a huge all-start turbo shoot out. I'll be eager to get a copy and see the results myself. Hold off your buying decisions until then.

 

400-420 doesnt sound bad to me. Isn't that right around what the APS makes out of the box?
JWT has quite a reputation for building rock solid products too. I wouldnt be so quick to jump away from this based on the limited info avaliable so far.

 

that's 400-420 flywheel hp at 8.5 psi and limited to 500 flywheel hp when the turbos are maxed out

so stock 6.8 psi would be what? like 365-375 flywheel hp?


APS does 400 flywheel hp or so on stock boost and already has a good track record. JWT as a company has a good track record and I'm sure their turbo will be a solid kit too. But the APS kit seems more capable and is solid and available right now.

 

Whether it was at the flywheel or at the wheels seems to be debatable. I agree that if it is at the flywheel then the numbers seem low. Just saying I wouldnt base a decision on limited and questionable info. CARB approval is important too (to me at least).

 

I thought THX just explained that the 8.5psi 420hp was at the wheels and not the flywheel? If you're saying that APS does 400hp flywheel stock, that's the same as what JWT is saying their kit will be. I am going to stop talking about this one until more information is released on this kit. I am excited to see that turbo shootout in Sport Z and after reading that mag I will be holding off to see what JWT has to bring to the table. Right now for me it's between JWT and APS. My friends all have 300zx's and SER's and JWT is all I ever heard for years now. When it comes to Nissan's they have the experience. I hope this kit holds up to their name. I've never heard of APS before I came to this board. That doesn't mean they don't make an awesome product.

 

Again, it is not 'flywheel'. The number is 'rear axle' derived ... as in all drivetrain losses have not been accounted for.

 

Thanks for listening kjbalto.

Link to SportZ magazine thread

The results should be very interesting ... can't wait!

 

Engine internals aside, everyone is overlooking one thing......All the power from those turbos has to get to the ground. Traction and control are major, major issues in cars with big hp. 420 crank hp, with the usual 275/245 tire upgrades, in my opinion, is on the limits of useable traction. Having your rear wheels spin as you shift into third at 60+ mph is not a desirable thing.

I'm really surprised that more people running over 400 wheel hp haven't commented on the severe lack of traction with that much power.

I still contend that there is such a thing as too much power for a given platform, especially one that is not all-wheel drive. Even with AWD, there is still such a thing as too fast for the street, simply because your car will gain velocity so much faster than other things around you.

The Z does need more power than it's stock form. It simply looks much faster than it actually is, but in my opinion, a properly tuned 320-350 wheel hp is ideal, and that is what the JWT power levels will be.