I have run my 62 on one of my cars at over 20,000 rpm'* for an entire season. That blower is now on my other car, and still has no problems.

That'* a great little movie on the working of your engine Julex.
Didn't know it had intercooling.

Hard to believe you have outgrown the M62 and require the M90. :?
Must be a real beast Cavalier.
Your girlfriends turbo unit gives me a woody just lookin at it.

as for Dynos, we got a good group of guys up here (New England) and do some dyno days.....check out www.nepontiac.org im over there as well

we do alot of Track outings to NED and being that your in NH you gotta be close

and i use HPT to tune as well, and its AWESOME

i got a friend with a 06 SS SC ...so im familiar with the car

I'm not saying I've totally outgrown it, but since I am at the "redline" after this Yea it will make boost but the heat vs psi ratio will change dramatically. And you can tell I already had it going far enough since it has a stress crack in it, but i don't think it is all the way through to the screws, cause I sprayed with soap and no bubbles. I'll get a pic to show and tell lol. maybe I'll get motivated and take off the SC if it'* warmer out sometime.

Nice I'll check out the site and look into the dyno days, we really want to dyno the cavalier also, dying to see what it'* putting out, but with my car at 300 WHP hers pulled harder with a stock clutch in it. Yea I went to NED alot a year ago but this past year I've just been in a real slump, and never got around to it. Next year will be different.

Room was an issue. With the adapter plate the hood will not close I know that. But that'* fine cause I'll just cut to slits in the hood, bend it up a little in the front and weld 2 pieces of sheet metal then bondo it clean and paint it. Will deff be a funny looking hood scoop, probably will look stupid BUT, It will not be done in vain

Now by inlet design do you mean the way it slopes down at the throttle body. or the way it mounts. Just curious .

BTW willwren what pulley size is on the m62? I'm just wondering to compare to my setup.

That depends on whether your crank pulley is the same as mine. What'* yours? You must know it if you calculated 16,000 rpm'*.

Your motor winds out and shifts at a higher rpm than mine too.

I gained power all the way up to 20,000 rpm'* at my shifts. Less each diameter drop, but that'* true for all pulleys, and I wasn't intercooled last year.

You aren't even CLOSE to outgrowing that GenV. Your car is what, a 2 liter? The M62 is designed for motors up to 4 liters (from 2.5 to 4.0). Twice your displacement. Did you know the M90 robs more power to turn it? That'* why the ratiings are what they are. The M90 was designed for 3.0 to 5.0 liter displacement.

So you'd end up putting a larger supercharger on your car and have to run a monstrous pulley, but it would rob you of more horses up front, because it has larger internal rotating masses. It'll cost you more to turn it simply because your engine is smaller than ours.

Supercharger sizes are carefully selected for the application for these reasons.

The crank pulley size is 6". I didn't calculate the RPm of the 2.7, someone else did, and the 16000 rpm is what I was told. Eaton never emailed me back with the info I asked for so really most of this is just what I researched and found.

Isn't the rating based on airflow really not so much the size of an engine? your saying that even if I have 700 hp just cause it'* a 2.0 four liter it can't have a bigger SC on it? and that the m62 will be fine?

Yes I understand there is more parasitic loss with the m90 I have the statistics on both of them somewhere. but CFM vs parasitic loss, I will be moving more air and making more power then what'* being robbed, I think. I mean the head I have on it, GM put out over 600 WHP without doing headwork to it, so it has pretty good airflow capabilities.

Why would I need to run a monstrous pulley? What I plan on doing is start with a larger one, but work down as I feel more comfortable with it. I want to be able to push atleast 1/3 more air over my current SC setup.

And I feel that I am over the limit with it, since I'm not the only one with trashed rotors and less than 15k miles on it. And cause of the heat I have a stress crack on it, so what will happen if I put out more with another one? probably be in the same boat.

Thanks

The size and flow of your SC has nothing to do with the coating loss or stress crack in the housing.


I suggest you port and polish a replacement GenV and get back to it, carefully watching your KR. I gaurantee you that my Series 1 with the Gen3 M62 outflows your 2.0 liter engine, and the M62 still suits me just fine. I'm still within it'* 'gain' zone with my smaller pulleys. The intercooler further helps you in staying within that zone. You have that advantage over me for another 30 days or so.

Hehe good luck with the intercooler.

Back to matter at hand, the stress crack is from the heat generated by the sc while boosting at that rpm. A bigger SC will move more air and have less heat. Yes more engine power loss, but the increased and cooled air coming should overcome that and add to it.

Also I won't get KR since I tuned the AFR and timing, and if I modify anything in there I will have to retune, so KR isn't a factor for me.

Your running a smaller pulley yes, but maybe the older gen'* can take a little more heat. I mean I could put stronger bearings that can take the heat and go up past 20k rpms on it BUT I will still be creating a huge amount of heat, and will probably crack the next SC unless I weld aluminum lines all over the SC case and run water through it to act as a water jacket.

Yea your running a smaller pulley, which is moving the SC powerband lower in the RPM range, but i've seen power curves for cobalts running a 2.5 and same mods and their power isn't any higher just getting more TQ down lower in the Cars power curve, but not necessarily adding more power up where I need it, in the powercurve I have. Which is about 48-6800 rpms untill I get in third I rev up to 7400 to cross the 1/4 mile line, faster times then shifting to 4th.

Please don't think I'm doing this to get on anyones nerves lol, I'm trying to learn, and by debating I'm saying what I thought were facts, against what you guys think, and maybe finding the hard facts. I won't lie and say I'm right on what I say, I'm just saying what I learned in my research. Thank you!

The heat you're talking about from running that high of a boost level is from boost stacking. You're producing far more than your engine can flow. In other words, you should be running a LARGER pulley. A supercharger is better described in CFM'* of flow, and if the manifold pressure rises too high, you're not flowing it, not using it, and not gaining from it.

You can't just pile on the boost because you have an AFC and a tune.

In addition, you will always gain less in the upper rpm'* with a supercharger. They become less efficient the faster they spin to a point. You'll still gain, but they are not intended for high-end power. If that'* what you desire, switch to a turbo and give up your bottom end.

I think if we give you a better description of the theory on flow vs. pressure, and displacement comparisons between your 2 liter and our 3.8 liters, you'll start to understand that the GenV M62 is still very well suited for your application. Even if you had a custom cam, stage 3 heads, bigger valves, headers, and the whole 9 yards, the GenV would still be very good for you. Remember, it'll keep up with a 4.0 liter. Your engine will not flow as much as a 4 liter stock for stock. Either with or without a supercharger.

I'd be looking for the true root cause of the SC failure. It'* not like your engine 'sucked the life out of it' or it failed from the high rpm'*. That doesn't happen. Many of the M62'* on this Forum spin far faster than your 16k, and I've had mine screaming so fast for a whole season that it sounded like a Turbo to some people.

In addition, there'* frankly very little difference between the GenV and Gen3 in either the M62 or M90. The Series 2 guys that upgrade to the GenV typically don't see very much gain. It'* one of the last things most do. You can run the same boost levels with a pulley .1 or .2" larger. That'* about the whole advantage in a nutshell.