Hi everyone,

I did a search and couldn't find anything on the subject so I figured I'd ask the question. I just rebuilt the top end of my 3.0L V6 in 89 Raider due to needing a head rebuild. Anyways, I had the cat gutted when the exhaust guides dropped to avoid plugging the cat and leaving myself stranded on the side of the road or trail. I will soon be replacing the cat and I wanted to upgrade my exhaust while I'm at it. I'm thinking of going with a 2 1/4" pipe and a high flow "turbo" style muffler. I want to free the engine up a little and maybe improve the torque on the engine a bit, not to mention add a nice throaty tone to it! <img src="/forums/images/graemlins/mrt.gif" alt="" /> Anyone upgrade this area in their rig? If so any recommendations? I'm willing to spend the money on a borla or flowmaster muffler but if I can get the same effect with something cheaper (don't want to sacrifice quality) I can't see spending the extra money. Any suggestions?

Not to dash your hopes but if your looking for HP you will not find it in a new exhaust. It might even be slower on take off because you will change your low end torque curve.

If your exhaust is in good shape I would just keep it stock Lots of other goodies you could spend that money on <img src="/forums/images/graemlins/smile.gif" alt="" />

My exhaust is pretty ragged right now which is why I'm replacing it. I wasn't looking for horsepower gains, mostly felt like it would be a little more free reving with a larger diameter pipe. Since I'm going to spend the money anyways....I was just looking to see what other people have tried and liked.

Just to let you guys on the forum know. I just rebuilt the 3.0L's top half, I need to replace the exhaust. The next two things I'm saving money for are to replace the whole suspension with new shocks and coils. I've heard a lot of good things about OME so I've been think about them. Oh yeah, then 31x10.50 on probably an 15x8 inch rim. From there I plan on fixing the body damage (minor rust at the back door and a couple dings) even though chicks dig body damaged! Then after I hit the lotter to pay for all these things <img src="/forums/images/graemlins/scared.gif" alt="" /> I'll slap on some paint and a winch. I'll be taking pics to post along the way!

DougH did a 2.25" it think on his 3.0L Gen2. And he said he was able to run a straight pipe all the way to the back - which is what I think would improve things most.

On the side. I heard Chrysler had to make thier 3.8L standard on the new minivans with stow and go seating because of the crazy bends, twists and loop-D-loops the exhaust had to do to get around the sunken floor.

The 3.5L isn't pretty either - lotsa crazy nearly acute bends to get past the axle.

I have flowmaster exhaust and cat on mine it sounds nice.I have never known it to be slower but i have the 3.0 and the 5 spd in mine and its really torquey.Although I never changed the size of the pipes just the the cat and muffler.sounds nice and doest sound like a tractor.

I know what you mean by the loop d loops pipes have to make now-a-days. I was originally going to try and get a Y-pipe into dual coming out the back end but there just doesn't seem to be any room.

Anybody like anything besides flowmaster? They've got a wonderful reputation but I always ask around before I set my heart on one thing. Definetly don't want my baby sounding like a tractor! <img src="/forums/images/graemlins/notooth.gif" alt="" />

2.25" is probably optimal for a stock 3.0L and the OE exhaust is less than that. The smaller size is good for low end torque but not for high rpms. With large tires, the worst place on the 3.0L curve seems to be around 1800-2000 rpms - just before it comes up on the cam.

I plan to build a 2.5" exhaust after the blower addition is complete... anything lost on the low end due to reduced exhaust scavenging should be more than made back in boost.

Frank

So is the worst place in the power band around 1800-2000 RPMs with stock exhaust or with the 2.25 pipe? When I add the 31's to the truck I should expect the larger pipe to help somewhat if I understand you right?

The larger exhaust probably won't help a stock truck until you're above 4000 rpms - it might even hurt the lower rpms.... but the only way to find out is to try it and see what happens.

At highway speeds, 1800-2000 rpms is a 3.0L dead spot with larger tires, engine loaded (uphill) and in O/D.... the A/T has to downshift to get the revs up into the curve to make enough power to accelerate. That's one reason I've swapped to a later transmission... the '91-'94 A/Ts have a lockup torque converter with a more favorable final ratio which should increase O/D rpms by about 200 at highway cruise - without the slippage allowed by the non-lockup models to get the engine in the power band. I'm hoping that the extra rpms will keep the truck nearer the sweet spot and I can then depend on the extra power from boost to get the truck to accelerate under load on the highway..... at least that's the plan. <img src="/forums/images/graemlins/wink.gif" alt="" /> Time will tell.

Frank