Does larger exhaust compromise low end torque ?

[Morganized]

I was talking to a mechanic the other day about an exhaust for my SVO. He was telling me not to go with 3" all the way. According to him I would be taking away my low end torque, but I would gain high end. He suggested a 3" through the muffler and 2.25" or 2.5" over the alxe and out the back. He says you need some backpressure to make the turbo work right. This guy did own two muffler shops and a garage at different times so he isn't completely nuts.

He also said to use flowmasters and not magnaflow mufflers though. He thinks Flowmasters are better quality, saying that the Magnaflow was just a "glasspack disguised as a muffler". I'm still leaning towards the Magnaflow.

Any thoughts on the exhaust size versus torque. I like my low end drivability.

[CP86SVO]

IMHO, any backpressure is undesirable on a turbo car. I went 3 inch from the turbo right to the tailpipe, with a Magnaflow muffler, and didn't notice any loss of low end torque at all...

I think turbine a/r makes more of a difference in low end torque and boost response.

I'm sure Mike et al will chime in soon with better explanations.

HTH WS

[NY eric]

The turbo will give you all the backpressure you will need. If you have a cat then that wont hurt either.

[Discord]

x2 For turbo applications...it's all about allowing that turbine to spool as quickly as possible. For that, you have give a little to get a little.

For a small displacement NA or centrifically SC'd car, yes, I will vouch that he is not steering you wrong. Have the dyno's to prove it too :-)

[Rob Hughes]

He also said to use flowmasters and not magnaflow mufflers though.

This statement just disqualified him from knowing anything about turbos...

[greg_pro50]

It would hurt low-end torque in V8 applications or I guess any N/A application. In a turbo application it helps out. I noticed a big difference with a 3" exhaust on my turbo 'bird. It spools much quicker.

When I eliminated the cats on my '92 GT and put 2 1/2" pipes on with flowmasters the car lost low end torque but gained some upper end.

[SVO-SMITTY]

I'm with Rob.

[Horsewidower]

The answer is no, emphatically no. I'm with Smitty.

[SVOeric]

has this mechanic EVER worked on a turbo car ? -- seeing his answers in your post tells me that he has not.... Backpuressure only slows the turbo down.

I have a 3-inch down-pipe, that Y's into 2- 2.5 inch with a mac cat-back on my 86 1E -- and it's got way more bottem end than it had stock (Dyno proven too!).

flowmasters are chambered mufflers -- magnaflows (the right ones) arent -- mufflers with a straight through design will preform better than chambered muffler on a turbo car. -- I'd also put magnaflow quality against flowmaster any time.

[NY eric]

So in other words... Run DONT walk away from this guy and find someone that will do it your way. I cant tell you how many so called mechanics have screwd these cars up because they have done this for 20 pluss years and built x-many race cars. The 2.3T is a weird little beast with many and I mean many specific issues (electrical mainly)

Good luck

[DAVEZ84SVO]

The 2.3T is a weird little beast with many and I mean many specific issues (electrical mainly)

Good luck

You hit that one right on the head!!




Very different from the N/A world.. But well worth it!!

Dave

[fordracing89]

I am with Rob, Smitty and Eric, not a flowmaster fan.. Have had three diff. magnaflow exhaust systems on three different cars. When I get around to it, that is what will be going on the SVO, the Turbocoupe and the Ridgeline.

[Morganized]

So in other words... Run DONT walk away from this guy and find someone that will do it your way.

Oh, I'm running. But not completely because of his advice. He actually did have some good advice also. What I couldn't handle is seeing this guy bending over under the hood with a red thong underwear creepin out. It's just so wrong. I think the Norge refridgerator repairman butt crack would have been slightly less disturbing. The turbo discussion was just frosting on the cake.

I know, TMI.

[NY eric]

What I couldn't handle is seeing this guy bending over under the hood with a red thong underwear creepin out.

Ew! just Ew!

[onthegosvo]