If I put a 50 trim turbo lets say... on a 427 Big Block. Or whatever... when would you start to see boost?

I once read that turbos DO NOT make boost til 2100 rpms or so. Is that true?

Because my buddy in his SRT4 says he sees 5psi @ 2000 rpms. I thought that's not even possible?

 

It's mostly in the sizing of the turbo. You could put a turbo on there so small it would right spool right off idle but end up being a choke point above 4500rpm. Your budy is probably telling the truth. A great book on turbos is Corky Bell's "Maximum Boost" and answers a lot of questions like yours.

Jim

 

Yep dead on on srt 4 i had a 60 trim agp on mine and it was spooled by 2700 easy.
That turbo is to small for our setups unless you want twins look at what others are using

 

I remember reading somewhere that turbos spool at 2k... it's just the way they were designed. I guess that's just wrong? haha

 

Turbos spool off exhaust energy. The more the engine is loaded the faster the turbo will spool, so with the correct wheel sizing and A/R you could have a turbo spool at 1500rpm or at 6500rpm.

 

i had a couple of buddies with SRT4's and their turbo's were nearly instant spool, but the turbo was the size of a dime

it doesnt neccessarily matter HOW much boost, but what the performance will do for your car. i only make 5.5-6 psi

 

Haha... and all engines spin to exactly 7K.

 

Way to many variables to say X turbo will spool at X rpm on X engine. Compression, cam specs, manifold design effect it, also placement. Those things alone have nothing to do with the turbo, that also with changes will effect the spool of it.

 

No man... no reason to be a dick. Just something to do with the turbo being the overall of turbos in general... not even sizing. That turbos will begin to make boost as early as 2k.

 

Sorry; wasn't trying to be a dick; just pointing out how broad the statement was.