I only have two words... MOAR PICS!!!!!!!!!!!!!!!! Where'd you mount the intercooler? Can you elaborate on how you tuned it (pics of tuning stuff)? Vids? Did you use Newcomer Racing's exhaust manifold? linky

 

dyno?

 

whos 'we'? is this a shop build? and X2 on the dyno sheet...cool tho.

 

Thks guys.
Sorry no dyno but I am pretty safe to assume 400+hp b/c i raced my cousins
2000 Trans Am with full boltons. He dynoed 385. When I raced I easily walked him.

I originally welded the intercooler on but then mounted with steel cables bc like I said I am parting with it. I am a new member so I can't put anything for sale.

The only reason I am parting with it is b/c I am upgrading to a 5.7 twin turbo.

I used Split Second performance piggy back computer for tuning. Works perfect.

My cousin and I built this kit ourselves.

Video on a youtube link below and more pics , the video was of tuning stage and was not running any where near its potential

 

Sounds like a cummins
the steel cables work better for custom mounting anyway - intercooler

 

gaining over 230whp with only 9psi of boost is a pretty "hefty" estimate


so, no video of the camaro race?


i dont really mean to question it to much, but a 385 WHP bolt on LS1 is not an easy task to build.

and a 385whp LS1 should be in the low 12's with a pretty average driver, and since you say you walked it.....


thats a pretty tough pill to swallow without any sort of proof besides a 5psi tuning video that doesnt show anything to impressive.

 

also i remember reading a build a while back with a t3/t4 on 22psi and only netting 310whp out of their 4.0

 

Looks great.
But 9 pounds boost should only gain about 9/17= 53% gain. On stock 190HP 4.0L + 53% = 190 x 1.53= 290HP, and you have stock head,cam,intake,TB so can expect a bit less. Chassis dyno is the only way to know, no guessing.
Where are you located?

 

Beat me to it^^^ The only way i see you walking a LS1 with 385whp is if its a matter of traction, or your buddy doesnt know how to drive. Either way, with the numbers your engine should be making with the mods you've mentioned i dont see it happening.

 

just so i can toss some comparison out there.

i happened to race a 310whp LS1, (just a filter and header back exhaust if i remember correctly)

i raced him in my 2wd, 5spd, 2door, 4.0 xj (light as they come) with a couple bolt on mods and a 120shot(more than likely similar peak WHP to your 9psi, but overall powerband with nitrous is much better ). i was only able to keep in front of him till above 90mph... then it just started pulling away, and didnt stop.

i would have never even thought of trying to keep up with 385whp one, that would have been ugly

 

My cousin's TRANS AM, not camaro, has more than just full bolt ons just saying that to be quick
heads, cam etc so yeah it makes 385 hp
the turbo is a gt35 it boost spiked to 12 psi, so once we got to about 40 mph the jeep walked it because of the boost. and if you don't know what walked means, it means slowly moved ahead at a "walking" pace.

It was hard for me to believe and the jeep was probably running around mid 12's.
We ran it again after fixing boost spike and the Trans Am beat it, now you can run it with 20 psi if you want, but if you don't have a rebuilt motor, you're guna blow it.

9 psi is a safe level for the 4.0 thats why I chose it.

I am located in Southern Michigan near Indiana border.

 

The GT35 turbo is so efficient, that a small t3/t4 at the SAME psi level will be much more restrictive with a 4.0 motor.

Unfortunately, I did not get a video of it running the Trans Am, and now the kit is off so I cannot take anymore videos, sorry guys. The problem was that it was on for so little time, once seeing the results of a GT35 I immediately changed my new project to a 5.7 L twin turbo the ultimate jeep sleeper ever

 

Theres not much difference between a trans am and a camaro... its like a gmc yukon and a chevy tahoe

 

the transam/camaro run the same exact running gear, a 380whp camaro is the same as a 380whp TA, just some different plastic. and i dont believe for a second that you pulled a heads/cam LS1.


fine, even at 12psi youre still not going to be putting down an extra 230-260whp over stock.

and its not about the PSI, its about the actual CFM being flowed, and the t3/T4 that was running 22psi (also intercooled) is still flowing more CFM than your gt35 at 12psi and the fact is, he had to run 100jet of nitrous just to get in the 377whp range. without it, he only put down the 310.


you cant have 1 supposed race and suddenly claim 400whp and mid 12's.


and yes, i know what "walked" means...and walking somebody makes you a good bit faster than them. too pull away at speed especially.


ofcourse you didnt, and of course you already removed the kit.


a turbo 5.7 in an XJ is not a sleeper by any means.

 

Obviously a camaro and trans am are the exact same car performance wise. I was just saying it was a trans am.
I was not trying to imply that it was faster than a camaro.

I myself am still baffled by how powerful it is.
Seriously it scared me everytime I drove it. And I seriously thought my cousin must have missed a gear or something b/c there was no way I could have beat his TA.
He swears nothing went wrong tho and also this was a very short race. I believe 10 to 60 mph.
If it would have been from a stop I am sure the TA would have beat it due to boost lag.
I kick myself in the *** everyday for not taking a video.

Yes CFM matters but exhaust backpressure can cancel out the effects of boost pressure. For example when I was in the building/tuning stage I accidently kinked my downpipe offroading.
The Jeep lost almost all power even tho It was still BOOSTING the same psi as it was before the exhuast kink. As soon as I fixed my exhuast it started making power again.

A small t3/t4 is generally made for small I4 motors. The 4.0 creates more exhaust due to its characteristics. (Higher torque etc.)
So a small t3/t4 will be restrictive in the high rpm range. It will spool right away but restrict the final power output significantly even if it makes the same boost pressure.

Some ppl argue that if a engine makes the same hp it must flow (CFM) the same. For example lets say a 2.0l I4 boosted to 20 psi makes 400 hp. Well then a 4.0 I4 boosted to 20 psi would make 800 hp as it would be able to flow twice the airflow. It doesn't work that way. There are many different factors besides psi and displacement that effect how efficient a turbo will be on a particular engine.

Its like saying a 400 hp, 2.0L, i4 honda engine, will flow as much as a 400hp, 16L, i6, 18 wheeler Volvo diesel.
Obviously I am not trying to be accurate but you get the point.

Anyway after the boost spike was fixed I estimate it was running right around 300 hp.

And you are right nothing is set in stone until it is dynoed.

After awhile my tranny started slipping due to all the power I was throwing at it. At 6 psi, it could probably have been driven for 5 years with no tranny problems, but a tranny rebuild with upgraded parts is a simple option if you wanna run more boost as the 4.0 is incredibly tough and can handle power like I have never seen before.

The only reason I am switching to a 5.7 twin turbo Is because I acquired a complete hemi and tranny.

I decided to build the hemi up and am trying to part with my 4.0 turbo kit.

If you have any questions feel free to ask and I am very sorry that I do not have anymore videos.