just saw these units, has anyone used one of these yet, looks to have a aluminum backing plate and decent specs....
http://www.ebay.com/itm/T76-T4-turb...Parts_Accessories&hash=item256d8cddc8&vxp=mtr

 

It has a p trim sized turbine. Too small for a V8 imo.

 

Its border line. I had a P-trim 66mm garrett on my HCI 306 and it revved out to 5800-6000 fine. I was only runnin 7psi though. I had it up higher a few times and it pulled great. Don't know what motor you plan on using it on but it could work fine if you cool with china quality. Pull it apart and clean it first.

 

thats the thing i was looking at, what turbine it had... trying to plan a single or twin 393" deal and a 306" single for some friends, quality "looks" better than the gt45 deals, dunno...

 

The 66mm compressor or even a 70mm works better at lower pressure ratios when paired with a p trim. They need more shaft speed to make boost. Turbines flow more the faster they spin, to a point.

 

^^^agreed. also another thought, I've actually heard VS racing (I think it was) say he felt p-trim 76mm compressors were under driven as the turbine diameter didn't provide enough leverage on the heavier 76mm wheels.

 

But my thoughts are that its $200 so its not too risky and plenty of people have used MPT 76 p-trims with great results. I think the difference is neglegible when wee're talking budget builds.

 

Not to start trouble by any means but you a the last person i thought would buy an ebay turbo after reading your back ground when the site changed hands. lol A 1000hp rating for $219.00 sometging just sounds wrong about that & don't forget the $95.00 shipping charge. Hey but what do i know. :noidea:

 

thats what i was thinkin, the mp76 has a p-trim, what is the trim on the gt45 deals?

 

I've never figured the trim of the turbine wheel, but it is much larger. The MP, and the ebay gt45 turbines are 87/77mm.

 

92 trim ? turbine side sizing is still my weak point ..

 

Power goals for the 393, and 306? The ebay gt45's have proven to be very cost effective turbos, but still has a small turbine for a 393 if its going to turn much for rpm, (IMO) and twin 76,s will support 1500 hp @ a 2.00 pr.

 

I come up with 78 trim for a 87/77 wheel.

 

the 393 will shoot for 800 or so , the 306 is a 68 block so 500-550hp.. both blow through.

 

Hahahaha I didn't even look. Thats great.

 

to figure trim 77 x 77 =5929
87 x 87 =7569 5929/7569= .7833 x 100 = 78.33 trim

 

thank you, now to figure out what flow for what hp... more reading..

 

Given that the GT45's 88 x 77 turbine, and even the S475's 96 x 87, work great on ~350ci, I can't see why anyone would on purpose pick a p- or q-trim wheel these days. Maybe for twins, but then the 76mm compressor is way oversized - you'd be better off then with 62s or 66s. T76/p-trim is a 3.0L Supra turbo.

GT45 on a tiny little 4.8L:

 

great vid 8)
now to figure a reasonably priced turbo for a 393 , compresor wise a 76 to 80 seems right

 

Is this a street, or a track car? rpm?
For the price, its hard to beat the Borg Warner s475 with the 96mm 1.32 a/r turbine. The turbine may be a bit small but, It should make the power your looking for, and you can upgrade to the 80mm compressor wheel later if you choose to.