Been driving around on current upgrades for about 4000 miles so I am thinking of the next step. Right now I have a rebuilt motor with about 10,000 on her. Upgrades I have done so far. Lindsey super 61 turbo, Lindsey dual port waste gate, 55lb injectors, 3.0 FPR. Vitesse MAF with SMT, MBC, I think thats about it. I would like to increase low end ( under 4000rpms ) and throttle responce. Right now I have no cat and 2.5 with a flow master muffler. With 15lb boost on a mustang dyno I got 298rwhp and 319tq. Will an exhaust increase my spool up time to give me more low end? Thanks for the input.

 

Yes. I would go to a 3" with a strait through muffler.

 

Pressurize the intake and look for exhaust leaks while your at it. 4000 rpms is very late for that turbo unless your running a t4 exhaust housing.

 

There is another post on here at the moment about the relative advantages of going to a larger exhaust. It doesn't seem definitive but most would agree that going up to at least a 3" system should help overall power. Some would say that by going larger you can move your power curve more to the right. ie increasing top end power at the expense of low end torque? Others say go as unrestricted as possible. The cup cars ran 3" into 4". I would think with the mods you have, something like the Lindsey 3" would work well for you. Having said that, I would ask what changes you've made to suspension and brakes. I personally think it's crazy to keep going up in power while on standard and probably tired suspension/brakes. The stock stuff is way too soft for any serious power upgrades as far as I'm concerned.

 

And ditch the cat. Assuming emmissions aren't a problem.

Big reds would also be a nice upgrade.

 

The suspension is already done. I had the intake system pressurized and everything is good. I have 18lb of vacuum and no leeks. I am probably alittle off on spool up. It is more like 3600-3700. I dont have a cat in the car right now.

 

If there are no intake or exhaust leaks, you have a good AFR.. A 3" exhaust "might" help spoolup some, if you want a better spoolup start looking at the turbo. (I know you don't want to hear it).