Hey guys I finished my 347 and am contemplating installing the turbo kit. This is a stock block and that is the only thing holding me back...

I am just not sure how low I can tame it down to? What is the lowest amount of boost I can possibly run and how much power with that give me?

forged 347 stock block with main girdle - 0 balance

9.5:1 CR

RHS 215 heads

Holley systemax intake

Custom FTI turbo cam .576/.566 230/228

The turbo kit is a PTK turbo kit with a 3" down pipe and I will using a used Master power 70MM turbo

 

Ok, same questions then with a used MP70mm

 

if you have a 94-95 i would get a boost brothers kit sell the turbo and go with 76mm turbonetics turbo.i know boost brothers went under but i got mine years ago and never had any issue with it.i sold the bov,wastegate,turbo and with with jgs bov,wastegate and the 76mm turbonetics turbo

 

I am not trying to crank up the boost.

If you read my post I am worried about having too much boost....


MY questions are

What is the lowest boost you can possibly make with a MP70 on a 347 with the posted comb

I have 350HP right now, what will it make on lowest possible boost?

Can i keep it under 500rwhp and keep it alive?

 

Just run 6-8lbs and see where you are at....are you locking out your timing or do you have a tuning device?

 

To be honest my goal would be 450hp. NOT 500 because of the stock block. I would not be able to afford a re-build of any type.


I have 350hp now.

Is it possible to only make 100hp off a turbo kit with my parts? I wouldnt even want 8-11psi.

I am talking 5psi

 

I would like to only run 5psi. as I know that 5psi will still be pushing the stock block with my combo.

i am using Moates QH

 

so 5psi would make 60-75 more horsepower than stock? stock is like 220hp?

what would 5psi do with 350hp 347 big h/c/i?

 

Oh ok, well that would be nice if that was the case.

Do you see any issues with getting the kit to go as low as 5psi? What is the lowest spring you can supply to me? I am using a Tial 38mm 2bolt style.

Thank you for your help.

 

I have a .25bar (3.75psi) spring in my 38mm gate. .25bar increases power 25% which would be 88Hp on a 350Hp engine.

 

How much boost does the 3.75 spring actually give you on your combo?

 

just under 4psi

 

Only if you don't add any heat to the air.

 

^^^ starts getting really complicated when you factor in reality. The simple answer to your question is you can run as little boost as your wastegate can maintain. There are kits such as the STS remote mount stuff that are designed to only run 5-6psi on the cars you put them on.

Read the turbo bible and you can see how heat affects your air flow, but it's all theoretical, every setup will obviously be different.

For my super rough rule of thumb, I do (14.7 + boost level) / 14.7. Take this number and multiply it by .85(assuming 85% efficiency through intercooler and all). Then multiply the final number by your hp number to get an educated guess(GUESS AT BEST)

 

super rough? kinda confused me there but Im kinda buzzing
so if I make 275hp NA, that means 10lbs would put me at 392hp?