87Pomona

Currently On3 Performance offers their 76mm Journal turbo with A/R sizes .68 and .81

I contacted them and they told me they are currently making some with 1.0 and 1.15 A/R

Would the 1.15 A/R hurt me in anyway?

Planned engine mods

4.8
--------
Ls9 headgaskets
Arp head studs
Ls9 cam
Pac springs

HRHohio

Front Mount? Rear?
What heads?
Rear end gear?
What boost are you going for?
What rwhp you shooting for?

Might hurt spool a little... just saying...

87Pomona

Front mount
Stock 706 heads
3.73
Shooting for 500rwhp

HRHohio

Well, I went with the On3 T76 Ball Bearing with .96 AR. It was a little more expensive, but I was told it would spool faster. (I'm rear mount btw).

I put down 551 rwhp @10 psi, but I think it takes a little too long to spool for my taste. I think .96 would have been great with a front mount setup.

Also, keep in mind that the exducer sizes are different between the On3 Journal Bearing and the On3 Ball Bearing.

If it were me, I'd spend the little bit more (I mean, the turbo is the core component of the system) and go .96 AR Ball Bearing. It's still so much cheaper than any other BB Turbo out there.

If youre dead set on Journal bearing, I'd say go 1.0 AR. Gives you room to grow.

Just my opinion...

ren987

iTrader: (4)

go with the biggest available, the turbine wheels are tiny on the on3 76mm journal bearing turbos

BottleFedZ346

iTrader: (17)

I run the .96.....

I was told they didnt have a bigger backside and all 76mm's came with .96, atleast when i ordered.....

Old Geezer

iTrader: (3)

Would be nice if they had compressor maps...............

Chicago TDP

iTrader: (3)

Just to put out there, I have a TC76 .96 AR Tnetics on a stock 4.8 with 317 heads....super doggy out of the hole.

I would say that if you keep the compression around 9:1 or great, you should be good.