Ok so my set-up is a 357cid sbc i plan on a running powerband to 5500 and want good power around 2000 rpms too


so i did my calcs and graph readin and came up with a TT T04E 60trim set up

i want to run 10psi but this turbo also will be efficient at 15 if i should choose

so i was wondering... what kinda A/R am i looking for to spool at 2000rpm and not hinder at 5500

 

What tranny and converter are you gonna use?

Even a smallish .68 housing will spool slow if a low stall 12" lockup converter is used. It has a lot of mass and takes more effort to get it spinning. A larger stall lockup converter will help but a 10" non lockup converter would work better.

I haven't noticed gear ratio sizing affecting the overall spoolup, most guys will use it to fine tune where they wanna go through the traps and on what size tire.

Two common housings are .68 and .96. On a smaller turbo like a 60 I'd use the .96. I believe that is most common on an 8. I'm switching over from the turbo buick world so 4 bolt housings will be new to me.....

Either way a p-trim should do you just right on the street with a .96 housing and the 60-1 compressor. Some manufacturers up their rating when they use the larger compressor housing(4in. inlet/ 2.5in outlet).

For example my last turbonetics was a 61mm compressor wheel with the larger housing and a p-trim with a .63 turbine, but it was sold as a 65 turbo. I believe the 62-1 is rated the same way. A 60-1 wheel with the large housing and a ptrim turbine....

I hope this doesn't confuse the **** outta you...

On a larger turbo for a street setup (like a 66mm) I'd use the .68 unless you have a fairly large cam and heads to generate enough exhaust energy to get that larger turbo moving.

There is a delicate balance of choosing the right converter that slips just enough to get the engine into the powerband to spool the turbo yet not too much that it robs power and is undesireable for street use.....

HTH!

 

Gunna be a T5 if i ever get in contact with this guy.... :sigh:


Well i have a custom ground Camotion cam. 221* duration and some holley systemax heads plus the block is punched .040 over

 

Who makes the T5 exhaust housing? I never heard of one. Do you have any dimensions on it?

 

He's talking a T5 tranny, and unless you are gonna spend some serious cash upgrading it you're gonna destroy it. It in no way belongs in what you are talking about building. On maybe a low geared road race car or top end motor with small cubic inches, but what you're trying to concieve don't bother.......

Loading that tranny against the engine when boost comes online is gonna kill it. Even more so with an good clutch. If you are gonna do a manual tranny (personally I wouldn't with a turbo car, unless you wanna hear the pssssh! from the blow off valve but hey it's your money)

Even a low stall heavy 12" lockup converter 700r4 will beat up on what you're thinking of. It's a lot easier going manual to auto as opposed to a auto to manual......

HTH!

 

Well I'm giving up on this guy.. aparently he does not want my money so I'm focusing my efforts on finding a T-56..... my orignal plan but the T-5 deal was too good to pass.... either way thanks.

 

If there isn't a need for a manual tranny go with an auto, it'll be easier to drive/ launch, you'll enjoy it more...

HTH!

Good luck!

 

I can;t wait to see how long my t-5 lasts behind a boosted V-8

 

well i plan on drifting... no need for the stick... but will help...


any who i've given up on my T-5.. im lookin for a corvette 700-r4 to hold me till i can afford a T56

 

Look for a 2004r from a monte carlo/ grand national, etc. They will take huge amounts of abuse are readily available, and are stronger than that weakling 700.

 

how can i be sure it is a 200.... ive heard about these but have limited knowledge..... arent they all or mostly aluminum too being way lighter.... is there an after market for these...

 

200's have a numerically lower first gear(less stress some say), the drop off between gears is less severe then the 700, lots of aftermarket support for parts like billet drum and input shafts. The bell housing fits both chevy and b.o.p..

There are a ton of guys running super quick with that tranny in GN's.

Do a search in the tranny section of turbobuick.com There's lots of helpful stuff out there. I personally will be going with a 400 and a numerically lower rear end.

Example: th400 with either a 2.77 or a 3.08 gear. It'll keep the rpms down on the road, won't be too severe going through the traps on a 26" tire, cheaper to build and should hold anything I'll throw at it.