Thoughts on Engine Build & JWT TT

A

Airvtec

Member
Location
Hayward, CA
Car
2006 FX35
I'm posting this thread to get all your opinions on this matter, as I'm no expert. I am still aways off before I have enough money for this, but thought I pick your brains. Originally I was set on getting the HKS s/c kit. The stage 4 kit from GTM is about $10,200, which claims a 160 whp. From reading all the HKS kits from GTM on my350z site, 160 whp is really pushing it on that kit. Also, with my drivetrain loss from AWD i'll be lucky to get close to that. Even if I do, that would be pushing the limits on the stock block. After my tune at GTM, my car came to 210 whp. Add 160 whp to that and you got 370 whp. With about 28.5% drivetrain loss, that comes to 517 hp at the crank. Of course this is if 160 whp is even obtainable with the HKS.

Now, I was looking at the stage 1 short block engine build from GTM. The price is $3700, which includes:
Labor:
Teardown inspection and cleaning of the core
Mag and micro polishing of the crankshaft
Balancing of the rotating assembly
Resurfacing (decking) of the block
Boring and honing of the block (with a torque plate)
Assembly of the short block

Parts:
Arias®/GTM® Extreme Duty or Wiseco®/GTM® Extreme Duty pistons
GTM® 4340 billet rods (with their alignment and resizing)
Rear main seal assembly
GTM® Race bearings (standard bearings available)
ARP® 8740 main studs

They claim the engine is rated up to 600 whp. Then I look at the JWT TT kit at $6300. The combined price of these 2 items is comparable to the HKS s/c kit. We all know the potential of the JWT TT kit.

Here are my questions: what other hardwares will be needed to get the JWT TT kit to hit around 500 to 550 whp? Out of the box, will JWT kit give me 500 to 550 whp? Also, I don't know much about engine builds. If I went ahead with the short block build, is that enough to handle the 500 to 550 whp? I'm talking about the engine alone. I already have upgraded TC & VB. Originally I was dead set on CARB certified kits, but I just can't ignore the hp per dollar return here. What do you guys think?
 
Bueller....bueller....bueller. No thoughts from anyone :confused:

Frankiago, you have a built motor right? What was done to it? How many hp will it take?
 
If I could do anything, I would do JWT TT and see how much motor building is needed. And there's plenty of room to upgrade from there.
 
Yeah, I do have the VB & TC already, but for some reason I don't think that will be enough for 500-550 whp. From the additional readings that I've done, it doesn't seem like JWT will do 500 to 550 whp out of the box. I was on JWT's web site and they have Rookie's car at 537 whp, and he has tons of mods. Anyone with built engine want to chime in? What was done and how many whp can it handle? Cost?
 
My buddy just did a full build and HKS TT setup on his 350Z with GT30's. It's pushin 530whp on low boost (not sure what psi yet). Can't wait to see it after it's tuned and on higher boost !!
 
I am in the same boat as you are - but I have done the JWT kit research. I looked at Superchargers first, but for the money, you can't beat a turbo. You'll probably have to tune DOWN the turbo to keep from blowing the engine. With a S/C you would have to try really hard to blow the engine.

If you already have the VB and TC, the only thing left for your tranny IMO would be cooling and maybe an inline filter. I have read up on several 350s and G35s that get up to 600 whp on stock trannys with those three mods (VB, TC, cooling).

The one thing the JWT doesn't really address is the ECU. Talking to a shop that I wanted to do the install, they recommended the pro-EFI. I think this means a new wiring harness and replacing a lot of sensors. Not a simple or cheap solution, but in order to tune it appropriately, for maximum power AND life, the engine management control is key. Stillen uses a piggyback ECU to manage the S/C. Not sure what HKS uses. You can probably get away with different solutions, some more simple and cheap - others more robust, but expensive. It will depend on your end game. But to me, if you are willing to spend almost 10K to get a bad-ass FX, what's another 3K? Just time to save it.

And then after you get power capability, fuel management comes into play. Bigger volume faster pumps are needed to handle the fuel demand from a built, boosted engine.

And your brakes, to stop this 500+ hp SUV, suspension and bracing to improve handling - to keep your wheels on the ground at speed. The list goes on and on...and I'm so glad it does.

:biggrin:
 
I don't mind spending a little more to have it done right. It'll just take me longer to save up. My goal is to near 500whp. Take into the account I have about a 28.5% drivetrain loss due to the AWD, the actual whp might be lower. I will definitely have to get the short block build to handle that kind of power. The JWT looks good, but not sure how much more money will be needed to up the hp, and ECU, and fuel. The company that did my VB & TC has their own twin turbo kit for the Z & G. When I'm ready, I'm going to see if they can fit that kit on to the FX. Their tt kit is pretty inclusive as far as ecu & fuel is concerned.
 
I would expect you should be able to reach these kinds of numbers with the jwtt kit, but do they offer any sort of upgrade to the turbo's they include? I guess one step up would be a good idea if that's a possibility... def would suck to have to buy it then upgrade the turbos...

I looked at the HKS kit, it was originally built around a rotrex charger which was awesome, then HKS decided to cut rotrex out of the picture & build there own chargers, almost a copy of the rotrex... from what I hear there in legal battles over that one... the rotrex units are pretty awesome, can't say much about HKS' clones though... & your right, the single smaller charger that they use is not enough for big numbers like your looking for...

I'm actually after about the same thing you are power wise, considering turbo's but I'm also considering & leaning towards just using twin rotrex chargers instead... cut HKS out of the picture, go with real deal rotrex chargers, & twins will be enough to comfortably achieve these kinds of numbers while still giving great low end numbers over a single larger charger, all with the reliability & safety of chargers over turbo's...


the jwtt doesn't include a very sophisticated engine management, most "kits" don't... it's all about price point, if they really included the best of everything in there kit it would be much more expensive, so most "kits" will cut corners to be able to bring a kit to market at a reasonable cost... it's almost always better to source & piece togeather your own "kit" rather than buying a kit... it'll cost more intially, but it'll save the waste that comes with upgrading later & then discarding what the kit included... kinda like buying a stereo, a complete out of the box deal will never be as good as sourcing each & every component of the best of each... after all, a real deal stand alone engine management will always be the best, but realize that a stand alone buy itself costs almost half as much as the WHOLE jwtt kit... the real question, how crazy you want to go?
 
The JWT set up can be done in 3 different turbo configs.

530 kit GT25
700 kit GT28
850 kit GT30

I love the FX, and believe me when I say this. The 5AT will be the thing that holds back the power. The 6MT makes roughly 10% more power same boost levels and the efficiency does not get worse and worse.

GTM and a few others offer up built trans packages and stuff. I have seen 1 dyno'd 5AT make near 600, and it had issues on the track with heat. 500ish is about the range of power I see, some guys with smaller turbo set ups make good torque since they spool up fast.

Bigger wheels, and more drivetrain loss equals a lot of work to get high numbers. Set your goals realistically for the drivetrain and you're be fine.
 
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