Supercharged VQ37 Goes BOOOM

Staples

Well it's definitely not going to be able to pull timing if it's before the charger because the MAF is thrown off from the get-go. You're throwing an obstacle in-front of another.

If you don't want to go with the HKS knock amp system then the AeroForce Interceptor should, as long as the ECU supports it (which it should).

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'08 Infiniti G37s - Forced Induction Fed

CrownR426

Wait what...?
Who doesn't tune their car after they get forced induction?
That's really silly...
Can't blame stillen for making a kit sounds like the installation itself was a disaster.

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Kyle@STILLEN

Hey Guys,

Just wanted to drop in here and post up real quick. Obviously seeing as how fresh this is, we're looking into it as well. As it has been mentioned, this kit is intended to run at 8 pounds of boost. Why it was running over 9 psi and then even further, why it went up to 10 psi after the installation of headers is very unusual and we don't have all the answers yet. Many of you will remember that when we developed the supercharger we mentioned that most of the time the addition of headers will lower boost pressure. We have found this to be the case. Now we're curious why boost actually increased after installing headers.

The kit was designed and tuned for 8 psi. We need to know why the car was running over 9 psi and then even bigger question why it went over 10 psi!

efuseakay

10psi. Something that was missed. I bet the owner messed with the boost.

BalanBro

Jordo's right. It doesn't matter who did the tune, at WOT, the ECU is in open loop mode which ignores the O2 sensor(s). It reads the MAF signal and has an internal look-up table to determine how long the injectors are to be open at a given rpm. It's up to the tuner who is manipulating this table to ensure that adequate fuel is present in each cell of the MAF load vs rpm table.

Similarly, there is a second MAF load vs rpm table for ignition timing that the tuner has the ability to adjust.

If you set either of these incorrectly, the car has the potential to detonate either from running lean or from having too aggressive ignition timing.

Also, a good, conservative tune should be able to compensate for slight variations in flow to through the engine. Increased flow from lets say, an exhaust should regester as increased flow through the MAF, which should in turn instruct the injectors to stay open longer. It won't be perfect, but it seems odd that headers alone would move you from conservative/safe to instant failure. I bet the original tune was borderline from the get. Maybe not with respect to AFR, but possibly with timing which is much more challenging to optimize.

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2012 Mercedes C63 AMG P31 Sedan, ROW, aFe, Eurocharged Dyno Tune. 438WHP/415WTQ
2010 SOLD: 40th Anniversary 370z

Staples

This post couldn't be further from worthless. As a buyer, the consumer should not have to worry about doing his / her research on which kit is better, both companies should equally do the same amount of research and development - ESPECIALLY a company that's been in business for so long. Safety should always be the first concern, then comes power. Longevity, reliability, maintenance are what a lot of people look for in forced induction.

Stillen, a known company for years has been making great aftermarket products for different car manufactures. To me, their flaw is their supercharger kits. This is not new since they were having issues ever since they came out with a root style kit for the 350z a while back (heat-soak, custom hood, lack of top-end power).

"It's really his fault. If all he wanted was power then yea, lean it out with the current set-up. But he should have told the tuner to leave it a little on the richer side if he was planning on headers all along."

You obviously don't know what's going on. He used a canned tune from Stillen that was "suppose" to be safe enough for him to use as a daily driver. Even adding headers, straight pipes, test pipes, high flow cats or what have you... it shouldn't affect the tune to the point it's too dangerous to even drive the car. The tune should be conservative enough to make changes without sacrificing the motor from detonation.

This isn't the buyer's fault.

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'08 Infiniti G37s - Forced Induction Fed

Staples

If it was seeing more then 9psi then there were boost spikes, possibly by weather or other factors.

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'08 Infiniti G37s - Forced Induction Fed

Jordo!

Huh? The knock sensor has nothing to do with the MAF sensors. Actually, neither do any of the O2 sensors

Both take readings after the MAFs and after the SC.

Whether or not the ECU can go into limp mode fast enough is a race between knock sensor sensitvity, the rate at which detonation is happening, and factory tuning.

Obviously in this case, the ECU didn't respond.

Boost is really just a measure of restriction -- what matters is the volume of air entering, which may be greater (even if boost is lower) thanks to the headers. If the fueling was off, and in-cylinder temps got too high (the reason you want to run a little rich is to have unburt fuel cool off the combustion chamber), the fuel may ignite out of time (causing preignition and detonation), which results in a good deal of shock to moving components, and boom -- something may break.

Looks like it shot a rod out the side of the block

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Staples

I understand that they're not linked... you're right, but as I said before it still boils down to the tune and MAF position. You don't need the knock sensors to pull timing if there isn't any type of detonation present. What would have caused the detonation from the get-go? Fuel, tune, too high of cylinder temperatures because of the boost spike maybe.

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'08 Infiniti G37s - Forced Induction Fed

Jordo!

Although if anything, better flowing headers should have reduced boost while still running lean.

I'm more inclined to believe that if the same pulley was used, the boost gauge was just off if it was reading higher boost than anticipated.

Probably it was just flowing more air, and ran lean, pop goes the motor.

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RCZ

Hey! Nice to see you guys are still around.

If it helps at all...when it went down into the 40's, I hit like 10.3psi with headers. Could easily just be someone who lives somewhere cold and has been hitting 10psi all winter...

Staples

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'08 Infiniti G37s - Forced Induction Fed

Josh@STILLEN

Not the same pulley.. this pulley is designed for 8lbs..

zzdudaka

I am curious to learn more about this and the cause. Many questions to be answered as far as i can see. Is the owner of the car not on the forum? Why has he not posted any additional info? Obviously he would want to refrain from posting if he did anying to possibly void the warranty? Keep quiet ; ). am Currently leaning toward the gtm, but no decision is made. I find it frustrating however that the first response from many folks is to speculate and light the torches as a first response. Soooo many details left out. It would be nice if we could just get factual info. This would help those of us still figuring things out come to a decision based on fact. I understand the experience some have had with stilen and by no means do i disregard that I do appreciate them sharing, but i would also like to suggest that stillen does add value to the community and to developing products for our cars. I like having choices for products for my car.

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Happy Z Motoring! zzdudaka
2010 40th Anniversary 370Z #357

toner123

hey some people are jumping to conclusions and making it seem like the missing pieces of the puzzle are the ones they added in. Stop with the torches and wait till we find out what the complete report is before we put some one to the stake and set the ground on fire. Just not enough information yet to determin fault.
Frank