After all the feedback and some other informative posts, im thinking this might be a pretty efficient reliable way to go for a 450 to 500hp truck that tows occasionly, would the garrett stg3 work well with the HX, what do you turbo gurus think?

 

I would say a Garrett GT4294r or GT4202r with a 1.15 A/R housing... The GT3788r would be much too small.

 

ditto^

If you're going to mix ball bearing and journal bearing, put the ball bearing on top where the spoolup will make a bigger difference. It's also cheaper that way, as large BB turbos can hurt that wallet badly.

The GT4294 can theoretically go to 500hp without getting out of the fat part of the map. The 4202 will go to 600 on the map.

Figure a little less than that for the inefficiencies of twins. I'd say 400-450 for the 4294 and up to 500 for the 4202 with good efficiency, put if you push them hard they'll go a lot farther.

A BB garrett stg 1 or 2 on top with a journal bearing 4294 or 4202 on bottom would work very well, imo. That's essentially the combo I'm hoping to build.

Justin

 

Not to steal the thread but Hohn I'm looking forward and this stuff gets more interesting all the time! Which Garrett would work best IYHO under my 13ss??

 

A k31 will save you a bit of money and spools very fast.

 

anyone know a good place to purchase Garretts, the k31 is a Garrett isnt it?

 

I know that PDR sells them, I'm sure there more out there. Search ebay you might a couple different vendors. If your keeping your HX35, go with the k31 or S400. There hot down pipes available and cold air tubes for that set-up. The K31 is wastegated so you can fine tune your twins. Limit your Hx-35 to around 20psi, any more than that will drive up your drive pressure and will be laggy, smokey and have high egt's. You have to balance the exhaust flow thru both turbo to get them to work for you.

 

K31 is a Borg Warner turbo.

 

If I could see a compressor map for a K31, that would all but seal the deal for me to use it as a primary. The combination of good flow, fast spoolup, internal wastegating and low cost is VERY tough to beat. Wastegating on the primary is VERY important imo, and going to an external on the big charger really cranks the cost and complexity up.

I've been told that the K31 and the garrett GT4202 are very similar turbos as far as mass flow and size specs.

If true, that would make the K31 an almost perfect primary for anything 550hp or less.

Anyone know how many housings are available for the K31?

Justin

 

The k31 only comes with 1 housing. It is a 1.24(I'll have to look at mine) But don't sweat the number. It spools very fast and easily supports mid 500's power with a 62mm s300 on top. I am getting ready to compare my K31 to my 72/87/1.1 s400.

 

X2 on the K31 housing...but IIRC, the turbine is the same, and I think housings will interchange. Not exactly sure, but pretty sure

Chris

 

I'm actually pleased that the K31 housing is sorta large-- I'd be looking for a little larger A/R anyway to keep drive pressure manageable.

jh