Andy@A&ACorvette

I spend a lot of time trying to talk customers out of upgrades, rather than into them. I see a lot of threads where people suggest that when buying an A&A system they should upgrade to a larger head unit.
I am, and always have been, a big proponent of using the correct head unit for the application. Buying a larger head unit and then putting a big pulley on it is just inefficient.
This dyno chart is of my own car. Bone stock vs. an A&A Si trim (3.4 pulley) a medium cam and ARH headers. I think this is a very common combination that a lot of guys would be willing to do.
I am spraying some Methanol on top but it's not a totally Methanol dependent tune. It made 719 on 93 Octane and no Methanol.
What advantage would I have by putting on a bigger (more expensive) blower and slowing it down so as not to kill the engine? None that I see.
The gains, as low as 2500 RPM, are huge and just get larger from there.
I just thought some of you would find this interesting.

old motorhead

Very nice How much boost?

chaver450

Yes, how much boost is that little blower making with that tiny pulley? I have a 4 inch pulley on mine and it pushes about 7 lbs.

Slo-Poc

Nice gains, wish it pulled all the way to 7k but very healthy useable powerband to say the least

Ill be calling y'all for a fuel upgrade here in a few days

Dragracer_Art

Mine is at 636rwhp right now with the 3.4" pulley making 12psi.

700 would be nice.

jon6.0

At what rpm are you making 12psi?

Slo-Poc

^^^remember that's an ls7 eating uup some of that air so boost will be different

Dragracer_Art

Here's the dyno sheet. Looks like 57-5800-ish.

I'm also pushing it into an LS2... not an LS7.

Dragracer_Art

I'm also curious how hard the Si can be spun ?

If you spin your LS7/Si combo to 7k with a 3.4" pulley... then maybe I can drop to a smaller pulley size on my LS2 ? Say... 3.25" and spin it to 6500 ?
I have a LS3 MAF conversion and 2nd meth nozzle to add also.

Two M15 nozzles at full-blast is definitely "meth dependent"

jon6.0

Cool. Thanks. I was going to put the 3.4 I have on my LS3 T-trim, but I think I will order the 3.6 first. At least until I upgrade the clutch. I'm at 578/511 on 7psi using E85. 6500rpm redline.

carlrx7

I had a 3.25 pully on my Si head unit for my ls2 with blower cam. made 14psi with e85, unknown numbers. probley made close to 700.

winters97gt

About what I would expect on that setup. I made right under 700rwhp with a ZR1 cam on the SI with a 3.6 pulley. A little more boost and a blower cam and I would have expected to see low 700's. Still a good blower for a street car and not looking to make big numbers.

Corvettinator

Where are you getting 93 octane (pump) gas in CA?

C7/Z06 Man

staticki

That is awesome that you are getting so much power out of it. I know I spoke to you guys about running a 3.6" pulley on my Si cammed LS2, but my tuner is really fighting me on it. They want to go with the 3.8" for a more conservative tune even though I am running e85.

C7/Z06 Man

What size motor, compression & boost?

jon6.0

Get a new tuner. I'm on E85 also. Mine wants me to pulley down as the 3.8 only gave me 7psi at 6300rpm. I still want to run 91 octane when I go out of town, so he wants me to stay 10-11psi so the timing isn't retarded low when I'm on 91. So I'm taking my 3.8 off and doing a 3.6 pulley. Heck, if all I ran it on was E85 I would use the 3.4 pulley I have. I still might when I do a better clutch.

winters97gt

Stock LS3. Stock heads, stock compression, 3.6 pulley.

Josh@AandASuperchargers

Andy only revved to 6,500rpm so as not to over-spin the Si-trim. With a 3.4" pulley and stock diameter balancer the Si-trim reaches max impeller speed as per Vortech website at 6,600rpm. Vortech rates it to 52,000 max rpm.
I've seen Si, T, and Ysi headunits over-spun to get more power out of them, but you proceed at your own risk at that point, lol.

Josh@AandASuperchargers

Stock compression LS7 and full exhaust it was hitting 9#s.