retrop

There is very little to know about the GM until it actually comes out. The major weak link compared to the pioneers, like JMC and the group with the Intense kit, is the pully size. Most people with high power are about 0.3 inches or more smaller than the rumored GM pulley that will be in stage 2.

The GM tune may be more conservative than the methods others are using but this is the big question on the worth of getting the stage kits....

Chevypowered

JMC, you said the crank pulley was 6 or less in. Did you actually take the wheel off and the wheel well liner out and measure it or did you just try to do it from the top and get as close as possible? I might take the wheel and all the liners out on the pasanger side and get a accurate measurment.

Badmunky

Why would you need to spin the motor to 8K? Its not a Honda. 6750 should be more then enuff. Mine hits the fuel cut at about 6400 on the tac.

Drewfu$

Are you trying to blow that thing up? I thought the blower was more than maxed out at ~17psi? What are you trying to prove? I think you've got something up your sleeve....

Tofu

I agree w/ Jmc on the blowers "max" from Eaton being conservative. I spoke w/ Bob Stiegemeier on the phone a few months back in regards to porting the m62. He also said that in his experience with the m62 it can handle " 17,000 rpms without sacrificing internal integrity as long as the supercharger is not spinning at that speed consistantly on a daily basis." Now I'm not sure how far that goes in his own point of view, nor am I willing to find out lol.

R33P3R007

i think he was talking about a 2.6 with stock everything else. not you and the stage 3 intense kit

R33P3R007

you guys are all crazy.. 8000 rpm redline, 20+ lbs of boost. I thought this thing was quick stock. 4cylinder and all. guess I was stupid. my bad.

Keep us posted and let us know what damage yall caue. so we can not.

Jmc007

At what altitude are you ? The barometric pressure (at sea level) is 14,7 PSI, but at 14 000 ft of altitude, it drops to 8,7. So that is a 6 PSI loss.

If you go to a 2,7" pulley instead of the stock 3,35" pulley, it will boost 6 PSI more over stock. If the total is still lower than 13 PSI, you shoud be able to run the stock injectors, until you run other mods. Still to be validated with a wideband meter for sure.

Jmc007

The main question is do you want to keep your OEM warranty !

Jmc007

It was just an estimate, since your car is a 05. Keep us updated wity your dyno results !

Jmc007

I got the wheel off and the bottom of the wheel liner out. I measured it with an external outside diameter caliper. I measure it the most precise I could, but it's a kind of difficult place to measure.

Jmc007

No, no, no and what's the last phrase means ...

Just for your info, I saw the manifold boost pressure goes up just past 22 PSI last night. I know that is too much for now, that's why I run it with care.

Jmc007

My thought is that we can benefit for the maximum possible TORQUE caused by the smallest possible pulley (probably the 2,6" pulley with a machined snout). Then, to lower the boost for the last RPM's, we could use a kind of wastegate or manual boost controller (set to 18 PSI as a pure example). We could plug it on the intake manifold hose ...

So the boost will goes up to roughly 21 PSI for the midrange, then lowers to 17 or 18 PSI for the last RPM's. Like the SRT-4 guys do (I think).

I found also that a MAP clamp will probably be useful too, helping us to tune the air fuel ratio in a better way. That's what I will try soon.

I also noticed that my Injector Pulse width is about 21,5 Ms at roughly 6 000 RPM's. Because the Max Boost is more than 20 PSI, the differential fuel pressure through the injectors is 60 PSI (fuel rail pressure) minus 20 PSI giving only 40 PSI.

Jmc007

Just bought this tonight ...

http://cgi.ebay.com/ebaymotors/Voodo...25082968QQrdZ1

AlphaJaguar5

Why...Would...You...Need...That

Shermen

mabey he plans on getting the twincharger kit. but thats a prity shitty boost controller if you ask me.

Chevypowered

I'm at 7,000 Ft. The pressure is roughly 3 PSI lower than sea level but with the air being less dense I don't think it can compress it as well and adding that onto the already 3 PSI lower makes it a 6 PSI loss. 6.5 PSI is what the interceptor gauge used to read when my car was stock, now I get 11.5 PSI here and 12.6 PSI at 5,000 Ft.

Jmc007

Will try to put this in line between the manifold hose and the by-pass valve selenoid, that's pretty cheap to do some tests.

Jmc007

I notice (experimented) that the Denso Iridium plugs helps a lot to eliminate the "bog" at low RPM's, since they need less energy to spark. For sure the better is to get some step colder plugs when changing the blower pulley size. First I ran the Denso Iridium #IK20 (same heat range than stock NGK) with a lot of detonation (knock) with the 2,6 pulley. Now I ran the NGK BKR7E (one range colder, V-Power Copper) with some less knock. I will try soon some Denso Iridium #IK27 (merely three range colder than stock, just like the NGK BKR9EIX plugs). Rob any knock with the 2,8" pulley ?

Leafy

Nice Jean Marc, can't wait to see more results.

06black

billetflow makes a 2.7in pully....just a lil fyi

Jmc007

I installed the Denso Iridium IK27 (three range colder than stock), but there was a LOT of knock with them. As expected earlier, since the electrode is so small and take less voltage to spark, they seem to spark either stronger or sooner, giving some knock (the timing being not optimised). I went back to NGK V-Power BKR7E.

Jmc007

Hey it's kinda cheap, very simple to install, and works VERY well ! I installed it between the by-pass valve selenoid and the by-pass valve actuator lower nipple.

As an example, I set it manually, and today my boost goes very quickly up to 16.7 PSI, and stay there until redline.

So with this device, you have the possibility to tune your maximum boost anywhere between 12 PSI (the stock maximum boost or the boost where the stock selenoid bleed the extra boost) and the maximum boost your aftermarket pulley can achieve.

For my example, I can tune the boost anywhere between 12 and 22 PSI with the 2.6" pulley !

It could be nice for those who want to run a small pulley (2.9" or less) and don't want to swap the injectors.

pclear9061

you havent blown your s/c yet?????? your god damn lucky

Leafy

Essentially, the supercharger is still producing maximum boost, but the bypass valve (with the controller) acts as a wastegate to allow only some of the boost to get to the engine... smart!