would a gt47 88mm or s480 be too small for a 427ci + motor? or do they like smaller motors? thanx guys

 

Yes,its too small.

 

what size motor would be max for that turbo? whats the smallest turbo for 427+ cid?

 

What is your goal? Track or Street car?

 

both if i can,or track

 

You can't answer this without engine speed. It would be plenty if power was at 5000rpm and you wanted 1kHp.

 

1000-1500hp goal

 

Gt4718 compressor wheel only moves about 1200-1300 hp worth of air. You'd be better off trying a 91 or 94 mm compressor if 1500 is the goal.

 

1200-1300 would work gt4718 a 88mm? what cubes would i want? what cubes w/bigger than 88mm?

 

The gt4718 is what people normally call the GT4788. If that horsepower level works for you, then I say run it. People might think it's a bit small but it does have a 93 mm turbine wheel and 2 or 3 different a/r housings. Prolly need one of the bigger ones. Set the rest of your motor up to make peak hp around or by 6500 and you should be good.

 

More info is needed, ideally something in the 95+mm T-6 would be needed.

 

well i was askin for info,if 88 needs smaller motor then might do that,if i do a big cube,then i may go bigger turbo. I just wanted suggestions of what 88mm turbos like. I wanted something i could maybe drive on the street so didnt wanna go huge but make 1000-1500 hp

 

Well most of the 88mm class engine are much smaller. They are more like 363 or less.

 

I think your fine to run an 88mm on 427"s. Here is my combo. 428" turbonetics Y2K 88 with .96 AR. The previous owner of this combo was running around 8.9xx with 16psi in his 88 notch. His street tune was something like a 9.4xx with 10psi. Now its in my 89 notch, on 275/60's. I would not expect to make 1500Hp with this turbo, but 1000 is a reasonable goal. The overal size of these Y2Ks is also very nice for packaging. For a street car, that sees ocasional track time, 88's are fine.

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Turbo matching is mostly about engine size and engine speed. A 363 that turns 7000rpm consumes about the same amount of airflow as a 427 that turns 6000rpm. Without knowing engine speed it is hard to say.

 

Yes....minimum 91mm is what I would suggest for 1500hp. The turbine side will be as much or more critical then the turbine side for that size motor.

 

I have similar combo I have a 408 victor jr f303 cam would a gt4788 be to big for the street true pump gas street car I was think a s480 with a smaller a.r. I want boost asap no tran brake jus foot brake the car

 

For quick boost, you might want to try the GT80. Quick on boost and will make big power.

 

well i can get a good deal on a crank & rods to make a 408ci. would a 88mm be too small for this cube or just right?

 

Hey Brandon........just saw this thread....motor/turbo looks great!!.......brings back memories. I was the original owner of this setup. I have no reason to believe that this combo would not have gone low 8's at 165 ish with 20+psi. I ran my times at 15psi on a very very conservative steet tune. With no boost changes, some C16 and decent timing....I woulda been at 160mph I'm sure. For me the 88mm was the perfect size for my 428"W. I spun it to 6700 with a small solid roller FWIW.

Rick