Too much boost..No added power?
 

I just put a 2.8" pulley on with Alky-Control. Previously just running 11psi and now 16psi. I just had it retuned and honestly can't tell a big difference in power. We were not on they dyno so there is no numbers. With 70-80 temps and running the truck hard for 10 minutes on and off I saw 135 degree IAT temps. I wondering if I could make about the same amount of power and be alot easier on everything by putting a 3" pulley on it? Maybe I need to upgrade heat exchanger now?

what were your AFR's and did you adding timing with your meth install?

I was told from Magnuson a bigger HX would be $500! :eek2:
Perhaps, it's less from someone who sells Maggies.
I was thinkin they'd be closer to $200, maybe $250 at most. :( :cry:

Considering I don't even have my Radix on, I don't think for me, I'll be spending $500 on a bigger HX. I wanna find another option or 2. But I may do something else instead of their HX. :secret2:

He had it setup 10.9-11.1 with meth. I thought that was too rich but I'm a newbie when it comes to tuning. I was thinking with meth it should be around 11.5?? Yeah he added timing. I thought maybe I'm driving the blower too hard now and building too much heat. I had a 3.2" pulley on it and made about 11psi.

I think that you're a little too rich. That's robbing power for sure. If you're still running the stock cam, that's really holding you back, alot more than you think.

16psi? Wow. How are you driving the blower?

Definitely not the stock cam. LEP blower cam....

Front drive front inlet blower with Innovators 10% overdrive 8 rib pulleys.

Gotcha! Keep working on the tune, lean it out a little bit at a time and keep an eye on KR. Then start playing with adding timing.

That was what I was going to ask, but the 8 rib setup is probably holding good!





Off topic but what wheels are those? Truck looks sweet.

Those are TBSS 22" replica wheels on Silverado lug pattern. You can get yourself a set here:


http://www.gmfullsize.com/forum/showthread.php?t=189128

how much power are you putting down right now? hp/tq?

Haven't dynoed it.

On my list next is a different driveshaft then I will take it to the dyno. Maybe some track time too. What I really need is a good tuner that I can trust.

I think you have more trouble than just running a little too rich. Too rich at 11psi and then too rich at 16psi should still yield a noticable power increase.

It was fine at 11 psi but I think it is tuned a little too rich now running 16.
If I back the meth off it is fine.

You will not see enough power increase to warrant the risk of running it leaner. Did your tuner see a noticeable increase in air flow through the MAF? injector duty cycle stay the same or go up even with the addition of a meth kit?

Not for sure?? Should it be running that rich with the meth?

Are your IAT measurements taken before or after the blower? I'm willing to bet the blower is putting out significantly more heat @ 16psi vs the previous 11psi that you were running and could be working against you...

I agree with the above post. Some blowers don't work well with high boost levels. They fall on their face and make too much heat. You end up with more boost but not more power. Hard on the motor too.

I don't know what type of blower you're using, but if it's a roots style blower they are the worst about doing it. Roots blowers work best at lower boost levels unless you have one setup for racing. Then it wouldn't last long on the street.

If that's the problem and you want to keep running the same pulley, you might consider a cam swap. A bigger cam will allow more air through the motor and the boost would go down, but the power should go up.

From the first post it looks like IATs got up to 135 after some hard running. For 16psi and 70-80 degree ambient temps that is really good for this type of blower. While it hasn't been posted and I'm just guessing I would say IATs didn't go up more than 30-40 degrees from the 11psi run. 5psi more should more than make up for that increase in IATs from 11-16psi. I would think.... :)

I'm running more boost with lower IAT's so you might want to look at a larger heat exchanger.

Did the airflow increase result in you running lower timing? The additional boost (cyl airflow) could have moved your timing into cells that have lower timing values.

I agree that leaning it out isn't going to recover much power. 5psi on my truck made a huge difference.

Good luck

At the same ambients? That is pretty awesome! :)

Isn't this the norm for that type of supercharger in that boost level? Not efficient at those boost levels and can't remove enough heat with the little intercooler. Running colder water through the intercooler will only help a tiny bit, the real problem is those little intercoolers don't transfer that much heat out of the charge air. This is one major advantage for centrifugal superchargers and turbos where you can run a huge 90+% efficient intercooler. Plus the fact that it takes 30-40 more hp to spin the supercharger than it use to at 11psi.

What Supercharger are u running, MNC5? Pulley size? And lastly, what HX did u go w/.?

I was thinking heat exchanger also. Need to find something bigger. I was also thinking about putting a 3" pulley on there which would put me around 13-14 and try that. Would be easier on the engine also.