Yeah, I get that. I just think we max our MAP sensor out around that 22 psi number. So I don't know if you could run much smaller without a MAP clamp or something. It would still be damn good. I would LOVE to get rid of that much heat.

 

Whipple all the way.

 

The downside is it's always under load. Even with the bypass.

The other thing is the last time I spoke to Whipple they said the W75AX won't be ready til the end of the year.

 

Does Kenne Belle have one of a similar size to the 75?

 

Nope. The smallest they have is a 2.2 I think.

 

Well if an M90 w/ bypass valve can put out comparable numbers to the whipple, then I'd change my vote to the M90.

 

The M90 consumes more power and woun't be as efficient at lower rpms.

 

The whipple is going to cost more than the M90, period. The 140AX is the only whipple option I can use, which is going to put out far more power than I probably want (In excess of 400hp) since the blower is .3 liters bigger than the engine. This also means I would have to port the head, special exhaust, and probably new pistons and rods just to handle the load of the boost. It's starting to sound all too much like a Honda build-up, let's not forget stronger axles and clutch just to hang with this thing. I'm siding more with the M90 blower, ported, and double aftercooled just like I thought before. This would cost ME less than 2 grand, and certainly put out enough power to make way for a mid 12 second pass, IF I could hook up enough. Until I have an upgraded clutch and axles, I could only boost to 12psi on the M90, until I upgraded the clutch and axles, still making another 50hp or better, which is enough to hang w/ LS1's and GT's of the sort. Might I add the M90 isn't even in it's efficiency range at 12psi boost...only at about 17psi will it reach a good efficiency, which means that blower could probably make more power than needed to make a car fast. Personally, if I reach 350whp, I'm going to stop there. Because it's a street car, and I'd rather do a weight reduction, maybe 150-200lbs, and gain about .3 seconds on the quarter mile, instead of adding 50hp to do the same. Reliability is paramount folks. Besides that, a 350+whp 2700lb Balt could probably pull on a Viper in a roll-on. Fast enough for me. If I could do all this for a reasonable amount, say $3500 bucks, clutch, axles, injectors, fabbed blower, aftercooler, and HpTuners with a tune on a dyno? Of course I'm going this route. If you think otherwise, please give a detailed reason why I should do it YOUR way. I need specific facts and numbers to back up your opinion.

In regards to Cobalt Supercharged....the higher the output of the motor..(Meaning the higher performance)...the greater the peak will be of the RPM. For instance...I have a 97' Z71 4WD truck. It makes about 255hp and 300ft/tq. Well, it's all peaked at about 2500rpms. Take that same 5.7L motor (350ci) and let Corvette modify it. The car now makes 350hp, 350ft/tq but peaks at about 4000RPM's, maybe 4500. Same motor w/ higher performance = less low end power. That's a known fact about engines. The peak power will shift the higher you go up in cumulative HP and TQ. Same thing with turbos. Make more total power, just later in the RPM. And we all know that doesn't matter so much when racing.

 

I meant that the S/C isn't efficient when spun at lower rpms as in a larger pulley not the engine rpm. I understand that twe really don't need the lower rpms for race cars since most of the time is spent in the higher rpms.

It really doesn't matter how large of an Eaton blower you use, they are not designed to be efficient at high levels of boost. Shoveing more air(CFM) in the same amount of space is always going to create higher pressure. 12 psi with an M62 will produce the same power as an M90. (Actually the M62 would probably result in more power to the crank because of the greater parasitic drag of the M90)

 

Somehow I disagree with this statement. I've got professional builders that tell me differently. An M90 is not efficient at the same level of boost as an M62. M90's create good boost right at 12psi and up to maybe 24psi because of the larger plenum AND the guts of the blower. M62's are designed to be efficient between 6-8psi in stock form. The M116 blower is not efficient until about 22psi, because it is designed for the largest of V8 motors. Same thing with turbo's. Smaller turbo's are efficient at lower boost settings and spool much faster than the larger ones, but do not flow near as much CFM. So yes, the M90 ported will make boost alittle later than the M62, but will offer a heavier punch once boost is created. It makes no sense to say that the M90 will not make anymore power than the M62. IT FLOWS MORE CFM. And if you have corresponding upgrades to outflow the input charged CFM, and you have sufficient fuel, the car WILL make more power. Period. Besides that, the M90 has a greater efficiency range since the boost can go beyond 17psi efficiently, unlike the M62. Now, having that said...I do believe the M90 will be far more effective IF the head was ported, bowl worked, polished and had higher flowing and more durable vavles, springs, and retainers. I'm telling you, I could replace the blower only on the LSJ w/ an M90, get HPTuners and larger injectors and I could see obvious increases in the results.

 

Right. 12 psi on our car with an M90 would be out of the efficieny range of the blower. What I was say is that people tend to think that 12psi with an M90 is better than 12psi with an M62 because the M90 supplies more CFM. You are right about the M90 being more efficient at higher levels of boost, but it is still not as efficient as a W75AX at the same level of boost.

 

Right on, your leading this thread in the direction I wanted. The whipple is obviously a better blower because it is more efficient. However, fabrication will cost more. The M90 is almost the same dimensions as the M62 and could feasibly fit in place with minimal effort. Pulley design would be very similar, and belt issues would also be minimal since the blowers are essentially the same design, only different sizes. These are the issues that stand in the way. Let's not forget that the M90 is 15ci larger in size than the W75AX. I think performance would be similar, with the W75AX coming out stronger by just a hair. I've decided not the do twincharging because of this and this alone: Turbo's create massive heat. So, in order...the turbo creates boost, makes lots of heat, and then pushes that hot, charged are into yet another charger, furthermore making heat. The car could not be run hard for very long periods of time..the motor simply could not handle the heat. I also realize you could intercool the turbo before sending the charged air to the blower but this would cost WAY, WAY to much to fabricate the piping, and all of the parts to make this happen. That setup could run you easily $3000 and probably go way beyond that after installation and tuning. It would be better to just scrap the charger, mate a 2.4L SS intake manifold to the block, and use an SC61 turbo set-up for the LSJ motor. THAT setup would KILL anything remotely competitive to the SS/SC, including the SRT-4's. At 18psi on an SC61...you could reasonably expect around 400whp. Too much if you ask me.

 

Yeah I'm very skeptical of the Twincharge set up. Like you said, you are using the 2 hottest methods of FI to create high levels of boost.

I'll stick to my twin screw. 22 psi with half the temp and almost the same amount of power required to turn as the stock blower at 12 psi.

 

Kenne bell!

 

Whipple, if I was doing something as big as switching blower or something I'd go with a whipple. Way more boost, way less heat and drag. Its the all around best FI set up you can do IMO.

 

Come on you pussies you need this turbo
http://videos.streetfire.net/video/2...af4dd0584e.htm

 

you have to go Whipple/twin screw.

The eff% is SO much higher and it acts much like our stock blower in respect to low end power and heat creation.

BUT its SO much better at the higher boost levels most of us are runing.

 

Pshh! The W75AX can run 35 psi and still have less heat than an eaton at 20!