M62 vs TVS1320 boost

[Classy]

Hello!

So, I am trying to calculate pulley size for a custom TVS setup I am making for my Miata (I know I know) and I figured y’all would be a great resource to help fill in the gaps.

Some background, 2.5 liter with a M62 (2.6 pulley) making about 325 whp on 93 and about 350 whp on E85. I am making 9 PSI at the top of 3rd gear. I know that seems low, but I have spent a lot of time working on efficiency. My question is about trying to calculate pulley size needed to keep my car under 400 whp and I don’t trust boost calculators. The supercharger I am cutting up is from an Audi Q7 with a 3.0 V6 and the pulley on it is TINY (and 8 rib)

please help me figure this out so I can tune it easier and not blow my car to pieces

 

[Tinkles]

Crank pulley diameter factors into it too. What engine are you running?

My personal experience with a stock 2.2L Ecotec is that with a 2.9" pulley on a M62 I was seeing ~15psi max and with a 3.15" pulley on a TVS1320 I am seeing 17psi. I only ever made ~230whp with the M62 on 93 pump gas, but I am close to 300whp with the TVS and 100 octane race gas.

If you cannot find any solid points of reference to get a solid estimate, I would just buy the largest pulley available and start there. Maybe contact Smoothflow pullies and see if you can a custom one made.

 

[Classy]

Crank pulley diameter factors into it too. What engine are you running?

My personal experience with a stock 2.2L Ecotec is that with a 2.9" pulley on a M62 I was seeing ~15psi max and with a 3.15" pulley on a TVS1320 I am seeing 17psi. I only ever made ~230whp with the M62 on 93 pump gas, but I am close to 300whp with the TVS and 100 octane race gas.

If you cannot find any solid points of reference to get a solid estimate, I would just buy the largest pulley available and start there. Maybe contact Smoothflow pullies and see if you can a custom one made.

Thank you sir.

As for crank pulley, it is about a 5.9 inch pulley. I am running a 2.5 duratec in my Miata.

I haven’t pulled the pulley off the Audi supercharger yet, but I don’t want to waste money on pulleys too.