Mandrel Bent Stainless exhaust

Post by **PrecisionBoost** » Thu May 05, 2005 1:43 am

Well.... my latest project is coming along slowly... I'm about 80% finished my stainless exhaust system.

It's 2.5" in diameter and all curves are from mandrel bent tubing so it's a pretty smooth transition.

This is the "catalytic converter back" portion of the exhaust.

I have a stainless plate with the matching flange on it but I haven't finished cutting it out yet.

I still have to get the car up on a lift and fit some hangers but everything looks like it's going to fit nicely so far.

The only problem is that the exhaust runs right agains the parking brake cable in one area.

With the stock 1.5" it cleared with about 1/2" but now that I've got a bigger exhaust it almost touches.

I will make a heat shield to keep it from touching but that will come later when I fit the exhaust on hangers.

I have a flowmaster muffler and I removed the resonator which turned out to just be a big hollow void with a tiny hole going out the other end.

I don't know the exact size but it looked like it was only about 1" wide!!!!

Needless to say this has to be one of the worst exhaust systems I've seen on a 2.0L.

My friend who owns the local dyno shop thinks I should make 10hp out of the exhaust swap.

I guess we will see soon enough.... hopefully I will have it all together and bolted on by the weekend.... and if things are slow at the dyno shop (where I work a couple days a week) perhaps we will get a chance to check it out.

kinkyllama · Post by **kinkyllama** » Thu May 05, 2005 3:47 am

Im planning on having that done next week and i might be going to a dyno too. The local autocrossers want a dyno day and it made me wounder exactly how much power im making with my few mods.

Are you going over the axle like stock or what? I plan on going under then having the muffler angled a bit

daewooluvr · Post by **daewooluvr** » Thu May 05, 2005 3:48 am

kinkyllama wrote:
Are you going over the axle like stock or what? I plan on going under then having the muffler angled a bit

I think this is a very bad idea...

kinkyllama · Post by **kinkyllama** » Thu May 05, 2005 3:49 am

daewooluvr wrote:
kinkyllama wrote:
Are you going over the axle like stock or what? I plan on going under then having the muffler angled a bit
I think this is a very bad idea...

Why? whats wrong with it?

Chris, do you plan on doing the turbo really soon? Im just woundering if 2.5 is too big for our car as NA.

woo · Post by **woo** » Thu May 05, 2005 9:11 am

kinkyllama wrote:
daewooluvr wrote:
kinkyllama wrote:
Are you going over the axle like stock or what? I plan on going under then having the muffler angled a bit
I think this is a very bad idea...
Why? whats wrong with it?

Chris, do you plan on doing the turbo really soon? Im just woundering if 2.5 is too big for our car as NA.

ever go over speed bumps or drive on rouch roads???My uncle has a setup like that on his WRX and its expensive to always have repaired

MMamdouh · Post by **MMamdouh** » Thu May 05, 2005 11:00 am

woo wrote:
kinkyllama wrote:
daewooluvr wrote: I think this is a very bad idea...
Why? whats wrong with it?

Chris, do you plan on doing the turbo really soon? Im just woundering if 2.5 is too big for our car as NA.
ever go over speed bumps or drive on rouch roads???My uncle has a setup like that on his WRX and its expensive to always have repaired

i am not very experianced with exhaust setups and all but the "speed bump" bit seems not logical at all... if you go over a speed bump then the rear axel is raised up and their is no way the bump can hit the exhaust pipe if it is going under the axel, this is kinda like why a speed bump doesn't hit your front control arms even though they are too low at the wheel side.

any comments?

MMamdouh

kinkyllama · Post by **kinkyllama** » Thu May 05, 2005 1:20 pm

mmamdouh wrote:
woo wrote:
kinkyllama wrote: Why? whats wrong with it?

Chris, do you plan on doing the turbo really soon? Im just woundering if 2.5 is too big for our car as NA.
ever go over speed bumps or drive on rouch roads???My uncle has a setup like that on his WRX and its expensive to always have repaired
i am not very experianced with exhaust setups and all but the "speed bump" bit seems not logical at all... if you go over a speed bump then the rear axel is raised up and their is no way the bump can hit the exhaust pipe if it is going under the axel, this is kinda like why a speed bump doesn't hit your front control arms even though they are too low at the wheel side.

any comments?

MMamdouh

Yeah thats what i was going to say. I know what you mean though daewooluvr i have seen exhausts that look like they might drag on bumps. Some are really low in the back by the bumper

commuterspecial · Post by **commuterspecial** » Thu May 05, 2005 1:45 pm

Erfinder wrote:
I have a flowmaster muffler and I removed the resonator which turned out to just be a big hollow void with a tiny hole going out the other side.

Why make a stainless steel system and use an aluminized muffler??? Kinda defeats the purpose.

Post by **PrecisionBoost** » Fri May 06, 2005 4:26 am

Well.... I did have the turbo system in mind when I made it 2.5"

If your staying naturally aspirated 2.0" or 2.25" might be slightly better.

It's a toss up.... I would consider 2.5" to be the maximum size you'd want to go with on a 2.0L Naturally Aspirated car unless you planned on using some insulation tape (which isn't a bad idea )

If you think you might go to a turbo at some point I wouldn't hesitate to throw in a 2.5" exhaust right now.

And I'm absolutely for sure going over the axle..... going under would make it the lowest part of the vehicle.

I just realized I forgot to post the picture of the exhaust..... it's on my work computer so I will try to do it tommorow.

woo · Post by **woo** » Fri May 06, 2005 6:50 am

why doesnt any one have their exhaust shortened so it dumps at the back axel? My brother has had that setup on 3 cars with no problem. Instead of having no resonator and a muffler, you run no muffler and a resonator. Having no pipe at the back of the car makes the rear look clean and adds a sence of mystery

kinkyllama · Post by **kinkyllama** » Fri May 06, 2005 4:30 pm

Erfinder wrote:
And I'm absolutely for sure going over the axle..... going under would make it the lowest part of the vehicle.

Yeah but it would be the lowest right next to the wheel so you wouldnt hit it on bumps or anything. But if you ran over something

i see what you mean now....

Well i called around to have an exhaust system done and no1 doesn mandrel bent but i found a reliable shop to do full cat-back including muffler for $180usd

kinkyllama · Post by **kinkyllama** » Sun May 08, 2005 4:55 pm

Well i just had my exhaust redo a few days ago. 2.5 from cat-back. Damn! huge improvment over my last setup(removed resonator and just a performance muffler). Your going to be very happy with it especial coming right from stock. Over my old setup i noticed alot more power especialy in the top end. On the freeway i dont even need to drop it down to 4th anymore, although its mroe fun

woo · Post by **woo** » Mon May 09, 2005 10:00 am

i was driving my car with no muffler on the weekend. i had to take it off to put exhaust puttun around one of the welds. with only a resonator my car was loud as hell. It looked good with no pipe coming out the rear but it smoked out the interior. Its a shame i had to bolt the lukey back on for legal reasons...........

Post by **PrecisionBoost** » Mon May 09, 2005 10:54 pm

Here is the picture of the exhaust without the flange or hangers attached.

I fit the exhaust on a lift and tack welded the hangers and flange into place.

Then I went back to my shop and finished TIG welding the exhaust.

I have some pictures of it under my car but they were done on a friends camera so I have to get them from him later.

The exhaust is very loud and I'm thinking about adding a resonator to make it quieter.

As it stands the cat back exhaust made me about 3-4whp throughout the power range.

Top end power over 5500RPM was the most dramatic area of gains as the whole power band seemed to widen our around that RPM ( usually it drops off very sharply.... this time it was smoother )

As of the last dyno I'm making 123whp which is a 22whp gain over stock.

Given the stock horsepower at the wheels was about 18hp lower than the factory numbers at the crankshaft ( 101whp vs 119hp ) I'm guessing that I'm currently running about 145hp at the crankshaft.

BosnianLanos · Post by **BosnianLanos** » Mon May 09, 2005 11:46 pm

22 HP with Intake, Exhaust, and the underdrive pulley? If those are the only mods, than damn, that is a big increase for a 4 cylinder.

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Mandrel Bent Stainless exhaust

Mandrel Bent Stainless exhaust

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