I'm game. Let me get the exhaust opened up and I'll make the trek to SA. I knew better than to use the flowmaster muffs, but the exhaust "expert" said they were free flowing and quiet. He wasn't quite right on either count. They're loud and restrictive. I'll add cutouts and replace the flows when Corsa starts selling individual mufflers. That's supposed to start happening soon.

 

Hey Allen. Explain the speed density tune. Remember, you're trying to educate a dumb ***. Pros/cons etc. If the explanation is too long, just call me. I'd bet others on the forum would benefit from a little knowlege on this subject.

 

The main reason on your truck is to eliminate the maf, which should get rid of that vac you're seeing. I wonder if it needs a larger filter as well.

As for the pro's on sd tuning, the biggest thing you'll notice is a better running truck, smoother during a hard pull, and a less aggressive idle.

As for con's, I haven't ran into any yet.

see you soon,

 

I have. The 2 bar non maf tune is unable to adjust with air density changes. (Including extreme elevation changes) It can correct it with the 02 sensors but only at closed loop. Also a good MAF tune feels smoother to me. Don't get me wrong, I use and love 2 bar tuning, but there are some down falls. IMO

Allen, Couldn't the filter be causing the intake restriction? I thought the maf could flow plenty of air, it just could not read all of it?
Do any of you other RADISISY boys have intake restriction measurements to compare to?

 

I have an Outlaw CAI on my truck. It has a pretty good sized filter that I cleaned before I took the readings. The MAF is smaller in diameter than the 90mm throttle body + it has a screen that has to restrict air flow some.

 

My torque numbers were well above my Hp numbers. If you go to the corvette forum and read the posts about LS2 radix hp numbers, the hp/torque #'s are reversed. Always more hp than torque and always more hp than my 448. Wouldn't the bigger hp than torque #'s indicate they are making the HP #'s at higher rpm. I believe my heads are real similar to LS2 heads in breathing ability. LS2 has more compression, bigger cam (not near as big as mine), and a better exhaust (surely not as good as long tubes dumping into true 3" duals and no cats) than an LQ4. They have a better intake, but that is ditched when you add a radix. They have the bigger throttle body which I have also. Do the LS2's have a better flowing MAF?

 

I think they have the same maf

 

Allen did the speed density tune and eliminated the MAF. He said the truck runs smoother, but power is virtually the same. Still only made around 450 rwhp. Some of the dyno runs were made with air running directly into the throttle body with not even an air filter. Absolutely no restricton on the intake side. Freed up the exhaust with cutouts, but it made very little difference. Guess I'm bumping up agianst the 112's ability to pump air. I just knew my combo was going to be good for over 500. Part of the problem is Allen's stingy a$$ed dyno. He needs to have "corrected" numbers so I'll have something to show my HP challenged buddies!!!

Anybody done the 112 to 122 swap? What were your before and after numbers? How much boost is the 122 blower capable of with a 6.0L motor? I'm getting about 8 psi with a 2.8" pulley on the 112. Power comes on in a hurry, but doesn't seem to sustain it as the rpm goes up.

 

I am at 17 psi of boost with my setup right now, keep in mind I have the inlet forward design.

 

Inlet forward design? Educate me a little. I've talked to David (magnacharger rep) about the conversion. Is this the same thing you are running? I don't think my stock LQ4 would tolerate 17psi, but I'm thinking 10 to 12 cool psi would be just ducky. Want all I can get and still be reliable and civilized.