7MGTE T4 Turbo advice (PT5857 vs 60-1)

[johnb7]

Hey Guys,

Long time lurker but first post.

I have a built 7MGTE with standalone and all the supporting mods to make 500WHP. I am in a MK2 chassis, and don't really intend to use for more than 400WHP.

Here are my "bolt on" experiences:

Tried the LIPP boss housing with a Comp 60-1 Hi-Fi compressor and P-trim exhaust (~.81 A/R). Spooled terrible. Not even remotely streetable. Did 380HP/382TQ at 16PSI on a street tune. Here is the dyno:

Tried billet PT5857, pretty sure it was turbonetics knock-off exhaust housing. (A/R .70?) Spool was OK, and could probably be improved with exhaust port and more tuning. Internal wastegate was a worthless POS. Put in a decent bit of effort to fix it, gave up after close inspections shows multiple flaws/issues with design.

So at this point I came to the painful realization that if I want quick spool, precise boost control, and big power, I need to go true T4. I do not intend to buy a new turbo, as I think both of these are decent fits for a streetable 400HP 7M. So get a new exhaust housing and Treadstone T4 manifold. Question is which turbo is better, and what A/R? Also would a Quick Spool Valve help the P-trim spool faster?

1. PT5857 w/ .58 or .68 A/R (newer technology, possibly surge issues, more power vs. spool tradeoff)
2. Comp 60-1 P-trim w/ split .70 or .84 and quick spool valve (power and spool?, sounds fun, more unknowns, according to maps may surge)
3. ?????? another option

Input would be much appreciated. I am leaning one way, but some sound logic or more experienced input could easily sway it. I will make sure to post dyno results.

Thanks,

-John

 

[Nick M]

5857? That souns like a T04E wheel. My Boss Jr with its 58 a/r has it in 57. I have a stock automatic, so the power curve isn't comparable until I get the valve body done, and the lock up controlled. But it responds much faster than yours. You do know the 60-1 will make more peak power? Is the 5857 a T04E family wheel? The .58 is going to limit the peak number. Works for me though...

 

[Suprapowaz!(2)]

I have a Garrett T04E 60 trim on with a .70 divided hotside. I get full boost around 4000rpm. This is on a 7m. I don't like the lag. I wish I could afford a QSV set up but it's not in the budget right now.

I would be tempted to try the 60-1, QSV, on the .84 if I were you.

 

[al lewis]

I have a Garrett T04E 60 trim on with a .70 divided hotside. I get full boost around 4000rpm. This is on a 7m. I don't like the lag. I wish I could afford a QSV set up but it's not in the budget right now.

I would be tempted to try the 60-1, QSV, on the .84 if I were you.

Is your garret turbo ball bearing or journal?

 

[87targa]

35R t3 footprint small hotside should get you full boost at 3k. or you can go with a t4 with a small hotside, but that is a pain.

I had a 35r 1.06 t4 divided had full boost at 4k (no headwork just cams, stock intake manifold). or you can get the pte6262cea which is also an awesome turbo.

 

[hvyman]

Try and get a divided manifold and exhaust housing. It will make for faster spool.

I have a 6262 with .84 divided and get full spool around 3500-3800 rpm on a 1jz.

A tubular manifold will provide better flow as well. And external gates control boost a lot better than internal. I use a 46mm. You could use a 38mm.

Smaller the housing your going to have less top end but faster spool. Running a larger divided housing will allow you to have a better top end while still getting faster spool. Might have to experiment to see what your ultimately looking for. But running a dumped gate is fun.

 

[Nick M]

Or look at your longblock with regards to spool time.

 

[Suprapowaz!(2)]

Is your garret turbo ball bearing or journal?

Journal. I'm running a ebay tubular manifold. It's divided, and so is the turbine housing.