Did a search, again, and didn't really come up with anything concrete......I'll be running a 8.3:1 306 with stg 1 fox lake ported Victor Jr. heads, F-cam, and a fully Renegade ported Systemax intake.......My turbo kit is a new B&G kit with the Precision T70 and of course the .68 housing......I'm thinking that the .68 housing will make the turbo choke too early.....Not sure, but I think I'd be better off with the .81 housing at the least, maybe the .96.......But I don't want to wait until 4,000 rpm's too make full boost for I will only be turning this motor 6,000 rpm's max.......I'm running a 3.27 gear through an AOD, so that should help spool the turbo up a little faster.....I might have to run 3.55's with the F-cam, don't know just yet.....Any help would be greatly appreciated......

 

I am not really a guru, but I am running a .63 housing in a remote setup but I never see higher than 5200 RPM. Those heads have a pretty heafty top end flow, so I am pretty sure that housing will choke it down. Lots of people seem to be running .96 or higher AR on single underhood installs.

I think the F303 is a great NA cam, but there are many cams out designed specifically for blower/turbo applications. I'd hate to build an awesome turbo engine then it not see its full potential because of improper camshaft choice. Then again, the Motorsports cams are about a fourth the price of a custom grind without the wait.

 

The .68 should be fine for that combo, especially if you want it streetable. Search threads by FastAOD and Mad Beems - they both went ~130mph with these housings with similar combos.

 

i have a t-64 on my car with a .68 housing. i cant feel any restriction. it spools fast and is great on the streat. havnt been to track. but it works for my set up. see my sig

 

I disagree with you on that one. That cam will make plenty of power.

 

With a T-61 .81 p trim I see max boost @ 2,800 rpms with 3.70 gears. I think it would be very similar with a T-70 and a .68 housing.
Go with the .68.

 

I think for the best results in a "low" rpm setup (below 6000) you'll be REAL happy with the .68a/r. My .68a/r housing with the Q wheel continues to pull great hp at 6000 rpm and it hits hard down low...too hard at times! Although, I don't have any experience with the AOD/turbo combo's.

Jim.

 

:agree: I've seen t76's with f-cam make over 700 at the wheels....I think that for the money, you can't go wrong with a motorsport cam on a turbo application....Hell, you pick up e or f cam used for a ben franklin.....

 

unless you've seen what the fcam has done please dont reply the fcam has made over 1100hp on a 306. that sounds like a good cam to me and many others on here.

on another note
my 68 housing spools fine and doesn't choke either. i think your best bet is to try it out and if it donesn't work out for you then go to a 81 or 96 housing. the 68 will get you in the tens without issues and will split the block before choking aswell. if you've got a better than stock block and are looking for much bigger numbers than definetly get a larger housing, but i vote you go with it first and if it doesn't work upgrade.

 

I'd try it out and see if you like it. You can check backpressure if you want if you think it's choking it, but I'd try what I had first.

 

I gained roughly 300 RPMs in spool for a 4th gear roll from idle in changing from a 0.81 to 0.68 A/R.

You will probably give up 5-600 RPMs if you go to a 0.96 A/R, but you will likely gain some moderate power up top due to lower backpressure. One person a few months back posted pre-turbine pressures with all three and found the 0.96 was something like 33 PSI and I think upper 40s for the 0.68. I forget the boost but it was ~15 PSI I think.

I love my 0.68 on the street. But for the track, the 0.96 will likely be better.

 

It's going to be more of a street car, but will see track a couple times a year.....Sounds like the .68 is way to stay.....

 

I think that was JZ 97 SS 1500