not sure this is even a question that can have a good answer but was wondering about it.I got my 454 chevy with a s475 running and its a flattop 454 with roughly 550 cam for turbo.Has a 850 blowthrough carb running e85.Well the boost was alittle higher than I expected and we ran through 1st and second at 22 pounds of boost.I have been 9.6s with a 496 in this car and this felt alittle more than the 625hp 496.My question is could this have more hp than 625 with a 454 on 22psi with a s475bw.The feel of the turbo is totally different than the NA e85 engine so not sure if that's throwing me or not..Just looking for opinions and thanks in advance

 

You should easily have more than 625.... 251 n/a hp with 22 psi could make 625, and even a very mild bb should make that.

 

I figured the hp of the engine without turbo is between 275-300 hp.Im leaning closer to 300.It has a flattop in it and I put some slightly ported cleaned up 781 oval ports on it.I ran it in a monte carlo and with the 1/8th time to weight it put it very close to the 300hp number..I appreciate the opinion it just felt pretty good and I was alittle curious

 

300hp could theoretically become 740 with 22 psi.

 

thanks so much for the info.It felt stronger to me than the old 496 but the feeling was totally different..On the old NA engine it came on kind of even,with this it was like hitting 300hp worth of nos.Once the boost came in it was like a explosion..Very different feeling for sure..thanks again

 

i am at 650 flywheel at 10 psi boost with my 496.

 

Are you tapped out with the turbo.Basically could you run more boost or are you at the top of what you could do with those cubes and size of turbo.looks like a good build

 

The problem with the 475 is the turbine becomes small if you start to make much hp n/a on that many cid. The compressor can actually support a good amount of power.

 

I have heard that.I have a 496 that I was going to put this turbo on and was told that it wouldn't be a good fit.I was only going to spin it 5k or so but was hoping to get 800 at crank.My whole goal with this thing was to make a 8.9 pass in my nova.I had already went 9.6s with 625hp at
2600 pounds and thought if I can get the hp up to 800 I should be able to see the 8.9 mark..Im way behind the curve on the turbo stuff so have a lot of catching up to do and I really appreciate you guys opions

 

No I can get more boost if I want, I use a bleeder needle between wastegate and turbo and it is closed for now.
I seriously fear for my 4L80E and rearaxle with higher boost.
Bud boy do I want to up the boost.......

 

awesome and nice build.When I made the mistake and had it to 22psi I haven't been that excited about my car in years.This boost thing is addicting for sure..I appreciate your info and replies to this thread

 

that turbo is prob making 22lbs of positive boost and 40lbs of back psi just because a turbo can support xxx hp you still have to match the engine cubic inch ......that 475 would prob make more hp on a sbc at 22 lbs of boost than its making on that bbc