My car is a 65 a/c cobra replica. Running a 5 spd I was making 570 rwhp/600 rwtq on mustang dyno. Peak torque occured about 4500 rpm. I switched to a Lentech AOD with 2800 stall converter and it completely changed my car into a low rpm stump puller making 510 rwhp/740 rwtq at approx 14-15 lbs boost. Peak torque occured at about 2800 rpm. My set up is a Dart block 331, afr 185 heads, 60 lb inj, twin t3t4e turbos with a small .48 a/r on hotside. I don't know what the comp side trim is. Increasing the boost to 20 lbs with more timing and race gas yielded approx 600 rwhp/800 rwtq. The torque number may have been higher but they had to roll into the throttle to keep it from spinning on the dyno due to the 2800 rpm all at once torque hit and no weight over the rearend. This is my question. Is it worth it trying bigger turbos or hotside a/r if my goal is only 650 rwhp. Will a car that makes 650 rwhp but lets say 650 rwtq actually be any faster in the 1/4 than the 600/800 I'm making now? I hate to spend a bunch more money for little if any return. Thanks in advance.
Thomas

 

What time are you trying to run?

 

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Here is a graph dyno graph of the lower boost run on 92 octane. As far as time I would like to run, 9's at 145 mph would be nice at the higher boost level. Anyone have any suggestions?
Thomas

 

In an AC Cobra I don't think you'll have any problems running low low 9's with the current power you have. That car must be at or under 2500lbs it dosn't take much power to make it go fast. Your main concern would be the requried safety equipment to get those times legally and safely.

 

The safety equipment would only be required on the second run, which I figure they wont let me have a second chance at, lol. Seriously though, would changing to a .63 turbine A/R really make much difference from the .48 A/R I have now. Any input appreciated. Cheers.
Thomas

 

Isnt .48 quite small for a 331?
There was up there with people recommending .96

 

Speedy, I'm running twins, not single turbo. Cheers.
Thomas

 

Need some more info on those turbos. From the looks of the dyno chart, I'd say they are very[/b] small. I had a pair of T3/TO4E 57 trim turbos with .63 A/R turbine housings and Stage III wheels on a 347 and it spooled up a good 1200 RPM's slower than you. I'd be they are some tiny TO4B's or maybe like a TO4E 46-trim that is restricting your flow. Have anymore info on them? You can't even move to a .63 or .82 A/R housing untill you even know what exhaust wheels you have.

 

I know the exhaust wheel is a stage 3, I just don't know the comp trim.
Thomas

 

its typical for an auto car to show more torque than hp if thats what your wondering. It does this due to torque mulitiplication of the convertor. If you got the good strip terminator lentech then your good to go and let that thing fly!!! Bet a low 9 at at well over 140 will be easy if the thing hooks up!!

 

I drove the car approx 200 miles today out in the country roads, it drives perfect. Tons of torque when I blip the throttle after coming fast out of a corner, too much fun. I can't wipe the smile off my face. I guess I better leave well enough alone. Cheers.
Thomas

 

Just found out for sure I have the 57 trim T3T4E turbos. I guess that hotside .48 A/R must really be choking them up. I'm surprised I'm not surging when I look on the comp maps, considering how low the turbos are spooling. Maybe I should upgrade to the .63 hotside A/R. It appears that will increase the hp potential by 50 each turbo. Decisions, decisions.

 

I have Precision T3/4's .63 / 76 trim spools around 3000 rpm but lower with load on road... 7.8 comp 236 / 224 -114 lsa cam
TFS induction.. Made 483 rwkw / 650 rwhp... 3 inch dump pipes on both turbo's with internal wastegate port...
Imo the .63 would be far better esp with smaller trim ??
Mine is manual and with low comp its alittle throttle resistant till second gear or when load comes on..
A half decent auto would realy wake up 60 Ft times... Its not for 1/4 mile but I go there two or three times a year...

 

Did you get that car out of Alabama by chance?

What gear is in the rearend? You could put a 3.08 or even 2.73 and harness a little more of that low-end grunt.

 

Svooh, I have 3.08 gears, so I think I'm okay there. I need a price from somebody for a t3 .63 a/r housing with stage 3 wheel 5 bolt ford pattern.
Thomas

 

specs from on the engine dyno
twin 57 mm , 355 cubes
use the .82 a/r housings.....

with to4 super E comp wheels , 57 mm , stg 3 wheels, .82 a/r on 355 cubes, the torques was flat to 5100 rpm
never have too much torque

cheers
ash

 

I'll get you a price asap. Did you build the car? Or buy it (see my question above)

 

Matt, I bought the car from a guy in Florida a couple years ago. I changed the engine, transmission, rearend, fuel injection. The home made turbo system that came with it remains the same, so far anyway. Thanks in advance.
Thomas

 

Sent you a PM about the .63 housings Thomas. They would work really well on the setup...and bolt right in.