460rwhp Vortech?

[tony]

I went out cruising last night and saw a black G35 coupe with what looked like the same wheels Jeremy has, very nice and the supercharger was obvious when he pulled up. We got to talking and he mentioned Alans car so I'm sure he's familiar with the group. He also said he dyno'd somewhere around 460 at the wheels, not that I dont believe him but are those numbers possible on a vortech? He did say he's put a lot of money into his car though.

There was also a 350Z there with an HKS supercharger which was impressive as well, he said he dyno'd 369whp last week. He had nitrous though and I'm not sure if that dyno was with or without nitrous. Either way the kit looked complete but he did say there is no tuning and adding anything other than cams or a catback exhaust will make the kit worthless.

[Canton_G35]

did you tell them about our meet?

[tony]

Before I could mention anything to the guy with the black G a cop came and made us leave the parking lot as if we posed a threat. He said he goes up to Balanced Performance all of the time though. I'm sure I can get the 350 to come when we meet at Z1 again, he stays in Alabama and knows Russel & Lorca.

[Carlos Ramirez]

There is a guy in Marietta area that has a G35 Coupe with rods and pistons and Stillen Supercharger kit with increased boost that is putting down around 460RWHP he is also I believe running alocohol injection and around 12PSI of boost.

[Roller_G]

Me and Trin(Skyline guy) happen to go to Balanced Performance one day to pick up some stuff. We met a guy with a black coupe vortech setup with those mesh wheels, claiming he got those numbers with pinging.

I'll talk to Ed and find out more.

[tony]

That sounds like him Tommas, it seems like he's put a lot of time and money into that car. The only thing I was skeptical of was the Bra he had on the front of his coupe, it wasn't one of the clear ones.

Oh yeah, that same night I mentioned the guy with the yellow supra to you I saw him surrounded by about 6 cops getting arrested, not sure if he was racing though.

[Roller_G]

At first he told us that it was making 500hp... something boogus.We were like okay cool buddy we're a bunch of ricers and don't know our $hit. He asked Trin how much horsepower the Skyline had, Trin was like it only has about 400HP. Then that guy in the G35 changed/lowered the HP numbers on us. We went back into the car and was like whatever....

Once again I'll ask Ed for the facts.

[G100011]

at higher boost levels, what's the first things to go?

[Carlos Ramirez]

G100011b or G35d

The biggest problem with raising your boost pressure is the stock factory compression and what your net final Compression ratio becomes especially in regards to your total inginition timing.

Final Compression Ratio (FCR) = [(Boost/ 14.7) +1] x CR

And if you want to correct for altitude it is as follows

Corrected Compression Ratio = FRC – [(altitude/1000)x 0.2]


So for a G35c which has a compression ratio of 10.3:1 running at 12PSI

It would be
FCR = [(12/14.7)+1] x 10.3= 18.7:1
The question is this high?
What would it be on a Supra running 17PSI?
FCR=[(17/14.7)+1]*8.5=18.329

So most Twin turbo guys run 17-19PSI with some margin of safety all the time and get away with it? Why is that they can and most everyone else who add boost to a NA'd car can not?

Well to avoid getting into to long dicussion of an basically it has to do with heat on the motor, dish pattern, and timing.

But say you get around all that by running higher Octane and get your ecu to reduce your timing and you want to turn up the boost.

Your weakest link is going to the factory rods. How weak are they? Very good question but i would say anything over 500RWHP would be seriously pushing them if not sooner.

So what I am saying if you are running boost?
0. If running any boost get colder plugs, 1 Cold rating per every 75-125HP.
1. If you run moderate boost, retard timing
2. If you run lots of boost retard compression ratio
3. If you done 1 and 2 and are running more boost increase octane levels
4. If you done all 3 and are making lots of power replace rods.
5. If you are replacing rods , replace pistons because lower compression is also good, some pistons I like to see more use of endyn piston's with there Roller-wave technology. Or you could in theory just put a thicked head gasket.
6. You are making lots of power and are still worried? Replace the crank.

Now here is my thoughts on the VQ35DE motor, it is an awesome motor and has some of the best flowing heads out there now, however it was meant to be very efficient and therefore everything is lightweight. Thus things tend to be a little less beefy so the margin of safety is not as high. Having seen the motor apart I am concerned about things like the rods and then the crank and finally ofcrouse the aluminum block. What are these limits? Who knows but if you are not scared and got a spare motor (ahmmm hello Allen!) start turning things up maybe do so prework and get the other motor built and ready :-P

Oh yes I didn't mention that factory clutch will be a weak link and need replacing, and so will be automatic transmisions.

[G100011]

Nice post... tons of info in there.
Most specific question that I had was circumstancial I guess. I just see that no one really goes over 400whp on the VQ35DE without some type of work. This work easily costs thousands of dollars (in addition to the s/c or t/c kit of choosing).
Anyone, what would be your estimate on cost/pricing be for taking a VQ35DE from 5.5lb of boost, up to about 7 or 8 and staying safe?

[Carlos Ramirez]

For safety I would do the following for boost.

1. 440cc injectors
2. Technosquare ECU with the timing reduced, the O2 feedbacks routines softened, programmed for the 440cc injectors, and bumped rev limiter.
3. MAP ECU and dyno tuned car.
4. Premium fuel only 92+ octane
5. EGT probe off exhaust manifold the to watch that your motor doesn't get heat soaked and so you know when to start giving the car a break.
6. One step colder plugs.

And that should be safe to around 8-10PSI