help me spec a turbo!!

[1fstss]

My F1A is gone in 2 weeks. ive wanted to go turbo for a long time, i was made a very good offer on my supercharger setup so im pulling the trigger.
first...
383 9.5:1
Fully built 700 R4 full manuel valve body, 3600 vigilante converter
3.42 gear
installing a meth kit in the next couple weeks

looking for something in a T4 flange
want to keep something around the same size as the F1A as far as flow goes maybe a little bigger.
i have to be very budget conscious here, looking to spend no more than 1500 for the turbo its self. i know this is a tiny budget, but its what i have to work with.
the car is not a track car. it is a street car so id like to have some stop light appeal. my max revs are 6800-6900 so id like something that comes on low and hard. the car will be raced at the track on occasion, along with street duty. looking to keep the car in the 700-800 rwhp range

things ive comes to grips with
ill probably be getting a used unit (which im ok with)
ill probably only get a thrust bearing turbo for my budget.
and i have no clue how to spec a turbo!

What should i look for as far as turbos go. Sizes and what not. thank you in advance!

[shownomercy]

A old tc78, or a new 7875 from TC, or a old pt76gts, or the newer 7675 will be nice T4 units.

Or, you can get a cheapo ebay unit.

[Fastbird]

What he said. I'm a big fan of a 76GTS (now called 7675) from Precision. That is actually a little more potent IMO than the TC78 stuff. But, you run into some exhaust restriction issues at really big output due to the rather small .96 A/R on the exhaust turbine of the 76GTS/7675 model. I.E. you're right at the edge of the compressor map. Moving up to an 88mm is a better call, but that's a MUCH larger frame turbo with the T6 flange.

[dawdaw]

What are your guys opinions on the s480 and s488.. see a ton of them on the sbe builds

[Fastbird]

That's the cheap Borg Warner turbo right? Lot of guys love them and are getting good results, but they're freaking big. There's no way one would fit in my car (though I'm running stock radiator location/angled back like stock).

[shownomercy]

the BW stuff is also T6, and IMO isn't gonna give you teh quick response a smaller T4 unit would.

But, what do I know.

[1fstss]

I was kind of looking at bullseye turbos site at the s480 and s488.. Just seemed like they would be super laggy on a street car

[shownomercy]

My "baby" T4 t76gts just took my ~3400lb car to 140mph. So ya.

No meth either, and my radiator is stock, no cutting required etc.

All a trade off, cause my turbo will be out of steam soon, but, honestly, I don't need to go much faster.

[dawdaw]

Don

Get the 115mm . Might be doggy down low but after 45 sec of wot it should really make some steam :) lol

[ZOHAN]

76mm fed 115mm... haha

Making you silky smooth...

[dawdaw]

That's what you should do for yours woman....

[1fstss]

I was looking at the 7875 but I was told the turbine housing will be too small for me. Was told I'll run out of steam up top and it can cause back feed issues because of my cubes/compression. Was looking at the 7875 for sale on ls1tech.

[shownomercy]

Guess my 75 turbine is choking my engine super badly then. Def runs out of steam.

Oh wait.

[firebird_1995]

Guess my 75 turbine is choking my engine super badly then. Def runs out of steam.

Oh wait.

You running 383"?

[shownomercy]

You running 383"?

Yessir.

There is no argument that a S475/S480 will def out trap a small T4 unit, but IMO you lose the down low response.

Do you need a 150mph car?

[dawdaw]

The 475 and 480 are both offered in a t4 and t6 flange I thought?

[shownomercy]

The 475 and 480 are both offered in a t4 and t6 flange I thought?

http://www.himni-racing.com/turbochargers/airwerks-borgwarner-s-series/borg-warner-air-werks-s400sx3-75-s475-turbo-t4-turbine

Looks expensive, and still only has 74 turbine.

IDK.

[1fstss]

No but it would be nice... Lol. I'd settle for a 140 trap lol.

[firebird_1995]

Well TECHNICALLY its only 139 and change at this point......

[Fastbird]

I'm running the 76GTS (7875) on my 383 also and it most certainly does NOT run out of steam up top. I was, and I stress was, only trapping 135 and change but that was with a very very inefficient cam and a poorly set up car that I couldn't launch at all.

[1fstss]

Well looks like I'm making a good call on this 7875! I should add it's a .96ar...