Ok guys I'm new here and new to the turbo cars. I'm looking at building a s10 with a 355 3 speed auto and a 9" . I have been looking at these GT45's on ebay. Just wondering what kinda of hp people are getting. I'm seeing the companies saying 600-1000. I want to get 600-650 at the tires. Not sure if I would need to run twins or single would do it. As for the enigne looking at running all forged guts. A victor jr intake, heads not sure. It will be a blow thru set up looking at a 750 cfm from quick fuel. Not new to drag racing , just to turbos. Any help would be great. Would be nice to see low 10's in it.

 

Be sure to ensure the specs, ebay has alot of random gt45' s that claims 600-1000. I use the 69mm on a 351 and am pleased with it. The 78/76 can be had now for about $400 and is also a nice turbo. But for $200 you won't be disappointed in the gt-45, there just so cheap.

 

The one I was looking at was a 69mm with a 1.05ar. I wish it was below a 1.05

 

Same one I got, it is a very large turbo so make sure you have plenty of room for it.

 

There are guys making 600 whp, but that's really pushing it on anything with a decent flowing head, and that cid. If your build includes a decent set of heads I would look at something with a larger compressor, and I wouldn't run two of them at that hp goal.

 

I used to have a much larger turbo off a 14 liter detroit diesel. My buddy had it on his 455 pontiac. Ran like a raped ape. But it came up missing when we moved. That one was a s475 79mm/1.10 ar

 

.....I went with a 7875 on my '86 S10, little smaller framed turbo than gt45 and easier to package in an already small engine bay, billet 7875 suppose to put out 18% more than cast wheel a little more money....check with Viren at VS Racing.....he has both and a great guy to deal with....

 

Thank you

 

I looked at the On3 performance 7875 with 78/75 with a .80 ar for $400. Looks like this one might fit my build better.

 

....your welcome....

 

Keep in mind that if you have room you can get a 475 for about $200 more than a cast 7875, and its a turbo you know will last. The 7875s seem to be doing very well, but are still a China turbo.

 

302 gt45 69mm 1.05ar here.
im pushing 15psi, 450rwhp, back pressure is about 25psi.
spools 5psi at 3,000 rpm. great turbo for 400-500rwhp and <351ci
its is big and heavy though. 78/75 makes more power and is likely smaller all around.
like someone said, s475 if you have the room is excellent.

 

Yeah I might do an S475 not sure yet. Looking at a few, doing research right now.

 

If you planned to make huge numbers, like 800+, vsracing has the billet s480 on sale. $750iirc

 

Is the s480 physically bigger than the gt45?

 

Yes, it's like 1in to 1.5in bigger lol

 

Definitely agree about getting it thru VS racing. Viren was great to deal with. I bought a bunch thru him (turbo, WG, BOV, flanges, clamps, ect)
I've got a single 80mm Gt45 on a blow thru 406sbc. Mine made 580 @11psi to tire without professional carb tuning on pump gas. really stout but mild engine 9.5:1 dual plane intake mild 220 cam. 17" vacuum at idle.