I have my Greddy TD-07 kit, but am looking at other options before I get everything up and running. I was thinking about a T-66, and I found a new one that a forum member has for sale. The only thing I was wondering about, is that he told me the A/R that was stamped on the hotside was .68. That just seemed pretty small to me, and I wanted to ask others opinions. Here are a few pics of the turbo, just for fun. Has a 4" compressor inlet. My goal for my FC is ~400 RWHP, running pump gas ( ~14psi?). If possible to know just from these measurements, what kind of spool-up would I be looking at, and would it hold max boost till readline?

 

hate to sound like a dumbass, but im also lookin for a new turbo and would like to know exactly what all the a/r #'s mean. like on the hot side higher is better and what hurts you on holding full boost to redline? what a/r #'s on the compressor means like lower the # better spool up etc. i just wanna make sure im getting the best

thanx or any info

dont mean it to be a thread hi kack but its somewhat the same info

 

The .68 housing is indeed a tad bit small. Is the turbine wheel a P-trim? If it is, you can always just swap out the turbine housing for a .81 or a .96 A/R housing. 400rwhp should be acheivable at around 14psi. However, the sweet spot of the turbo is in the 20psi areas. The T66 should spool slightly slower than a T04S (aka 60-1), but quicker than a T04R using the same hotside specs and manifold.

 

So, would the .68 be too small for what Im trying to achieve? I know some guys use a T-66 in higher power applications (500 RWHP +), which is more than what I want.

 

Well 1.35 a/r ratios are common in Australia, and even 0.96 a/r are considered too small for any decent power really.

I guess it all depends what you want and what you can live with.

Obviously a larger a/r ratio will allow more top end power whilst sacrificing some spool up time.

All depends what you like driving with.


I'd personally say a 0.68 housing is much too small.


Your engine is ported aswell, so then 0.68 will _definatly_ be too small.

 

Alright, thanks that what I was thinking. WHen I think of T-66, a big *** turbo comes to mind. When he told me this ones A/R was only .68, I got a bit confused. I guess Ill either stick with mine , or keep looking. Yes, my engine has a large streetport.