wastegate/turbo balance ?

ryanss22 · Dec 5, 2012

I am building my truck 96OBS as a sled puller / weekend toy. I have a built top end, fuel system, going to run 300/200 inj, with an irate t4 kit.

Ok first ? I bought a new comp wheel for my s475 and am wonderoing if I need to have it rebalanced after I replace the wheel.

2nd ?- my friend/ builder helper wants to to put on a WG and I am up in the air on putting on a wastegate. Will it help with drive pressure and for pulling to help stop the turbo from snuffing it self out when the pan hits at the end... My turbo specs are 75/87/.90. Will a WG even fit under the hood of an obs?

Any opinons on this??

ryanss22 · Dec 5, 2012

PS, I will be running a 2.6 cover for pulling

85_305 · Dec 6, 2012

As far as rebuilding the turbo, as long as the bearings weren't toasted and the shaft/wheels weren't rubbing you probably wont need a rebuild. But if the shaft or wheels were any out of balance, I'd rebuild it to prevent another busted turbo.

Extended Power · Dec 6, 2012

The waste gates purpose is to relieve excess drive pressure. (usually at wot)

It lets you run a smaller turbine wheel for quicker response, and just dumps the extra drive pressure to atmosphere.

If your turbo is sized perfectly for wot, you won't need one, and to put one in would do nothing. And if it did operate on a perfectly sized turbine, the turbo would fall on its face so hard and fast, you'd think you seized the engine.

PSDEng · Dec 6, 2012

I'd be willing to be with a .9 exhaust housing that your drive pressures are going to get out of hand. If I were you I would put a bigger exhaust housing on it. Sometimes snuffing the turbo at the end is a good thing....

If the turbo hasn't previously been balanced I would send it out to have it done.

ryanss22 · Dec 6, 2012

What size would u reccomend? 1.0 1.10?? I dnt wanna go to bigwhere it wnt spool at all on the st... Would it be "best of both" to keep small housing but add a wg?

golfer · Dec 6, 2012

S475 with the 88Twheel...1.15(T4i) (or 1.10 if T4) works well with 300/200s without a gate...

if you were running 400/400s...you'd need the 'gate.

PSDEng · Dec 6, 2012

ryanss22 said:
What size would u reccomend? 1.0 1.10?? I dnt wanna go to bigwhere it wnt spool at all on the st... Would it be "best of both" to keep small housing but add a wg?

There's a big difference between not spooling "well" and not spooling "at all." I have the t4i 1.15 housing and 300/200s. It didn't even think about spooling until ~2200 rpm on the street. It was great on the track though, as long as your tuning is right....

ryanss22 · Dec 6, 2012

Ok.. Its a T4... Anyone selling a 1.10 houseing?? I figured I'd be into the 2k before spool up.. I'm thinking of going with beans tunes...

ryanss22 · Dec 6, 2012

What tuneing did you go with psd??? How can you tell if your turbo is sized correctly?? I am building this all this winter.. No WG would save a headache, since I got the irate kit without a wg mount... Any idea where to send out a turbo? I live in central upstate ny...