3 inch exhaust on stock car

[insanewayne]

I am looking for advice/info on doing this. Turbo cars want no back back pressure right? So what would this be like? FWD plymouth laser with 14b, And I mean full 3" turbo back with 3" DP and no cat...is there any kinda of supporting needs for having a 3" exhaust, all it should do is add Hp by allowing the turbo to spool faster and easier, right?. Someone educate me, I searched but couldn't find anything closely related to this.

Thanks

Wayne

Sorry if this should have been posted in the general forum.

 

[DiamondStarCar]

No, no mods are NEEDED. However, with a full turbo back exhaust you should expect boost to spike, so a boost controller and a good guage are both good ideas. Also, without that catalytic converter, expect to get a CEL throwing the O2 sensor code.

With any performance exaust, you are simply freeing hp by decreasing backpressure like you stated. This puts lets stress on the turbine making it more effecient hp. You are on the right track, good luck.

 

[insanewayne]

I have an aftermarket gauge, and will be getting a decent boost controller.

Why do you say I'll throw a 02 CEL code with no cat, my car has no cat right now and there's no code, the o2 sensor is on the housing, not the cat? Sorry I'm confused there.

Thanks

Wayne

 

[4gsx63]

Make sure to upgrade your fuel pump or atleast rewire stock pump. You still going to get boost creeps like a mofo in this cold weather.

 

[Cyclone_90]

No, no mods are NEEDED. However, with a full turbo back exhaust you should expect boost to spike, so a boost controller and a good guage are both good ideas. Also, without that catalytic converter, expect to get a CEL throwing the O2 sensor code.

With any performance exaust, you are simply freeing hp by decreasing backpressure like you stated. This puts lets stress on the turbine making it more effecient hp. You are on the right track, good luck.

A little confused here to on the O2 code. How can it though a code, its before the cat? It doesn't get a reading after it or do those O2 sensors somehow feel backpressure?

Kurt

 

[definitiveno]

A little confused here to on the O2 code. How can it though a code, its before the cat? It doesn't get a reading after it or do those O2 sensors somehow feel backpressure?

Kurt

There is another one after the cat

 

[Bailzz]

What? If there is then why did you not state where it is located? Are we talking about the same car? What would even be the purpose of an O2 sensor after an O2 sensor is placed at the start of the exhaust? To let you know of a leak in your exhaust system? :thumbdown

 

[FireyIce01]

because eclipses have 2 O2 senseors.... it's probably to compare o2 before the cat does it's thing and after.... *shrugs*

 

[insanewayne]

Ok wow, now I'm just confused.

The cat was removed on my car before I bought it, buddy said it was proffesionally done.
So there could have been one there before? Man as far as I have ever known there is only one o2 sensor. At least on the 1g's anyways, someone correct me or straighten this out .

Thanks

Wayne

 

[Bastard1g]

First generation dsm's have one 02 sensor. 2g's have 2. The second o2 sensor is the positive feedback sensor to communicate with the ecu on how well the cat is operating. This is only on obdII.

 

[Defiant]

What? If there is then why did you not state where it is located? Are we talking about the same car? What would even be the purpose of an O2 sensor after an O2 sensor is placed at the start of the exhaust? To let you know of a leak in your exhaust system? :thumbdown

The rear O2 sensor is to confirm the cataclysmic diverter is still working. DSM turbos have two, one after the turbine to tell the ECU if things are about to blow up, and the second for the cat's functioning.

Don't feel special. Some Fords have four. Just because they're Fords, I guess.

 

[DSMAWD2G]

Look At His Car In His Profile, He Has A 1st Gen.!!!!!!!!!

 

[2-0turbo]

As others have said, I'll reiterate. Cat-back, you wouldn't have any problems. Turbo back, it will pull great and sound great, but you are going to have some boost creep problems (not just spikes). You are going to need some extensive porting on turbine inlet, wastegate passages and O2 housing too. Otherwise, you'll not be able to control the boost. Keep this in mind.

The good news: porting is cheap. If you have a die grinder (not a dremel), all it takes is an investment in time. Search internet for extensive pics on what others have done and where biggest bang for buck porting is at.

 

[DSMJim]

You don't alwasy get creep or spike either. I had a full 3" o2 eliminator downpipe cat and exhaust on my car originally with my T-25 and an HKS EVC original and it never spiked or did anything. It's all in the boost controller really.

I was having trouble with my evc one day after messing aroudn with it and was set to goto the track that day so I just slapped on a manual from my buddy and the damnd thing keep spiking and creeping. Honestly I think manual boost controllers are junk and they are the cause not the exhaust but thats just my opinion. As soon as I got my evc working again it went back to normal with no spike or creep and i vowed then to never use a manual boost controller again. This was all on my T-25.

I did try one again with my external gate setup and 50trim turbo and it worked fine but thats because its an external gate not because the boost controller was magical or anything again went back to the EVC.

 

[insanewayne]

Thats very good to know about the MBC/EBC info, thanks alot Jim.

Can anyone recommend a good muffler to mate to a 3" turbo back, not insanely loud, just a nice deep sound you know? None of that angry bumble bee honda bullshit . (Is that sound even possible out of out cars? )

Thanks

Wayne

 

[rob_rousseau]

Tnankfully your DSM will NEVER sound like a bumble-bee honda. It will be quieter than one of those hondas even if you run WITHOUT a muffler. Turbo's make good mufflers

 

[91TalonTSiCT]

I used my Dremel because it spins 10k rpm faster than the die-grinders I found. It worked just fine.

 

[DSM Demon]

or don't run an exhaust at all

 

[joelude]

I was wondering if any of you could direct me towards a link or some pics that show the porting of the o2 housing, turbo inlet, and wastegate passage. Something that shows clear pictures so I have a good idea of what to do.

 

[Steve93Talon]

You don't alwasy get creep or spike either. I had a full 3" o2 eliminator downpipe cat and exhaust on my car originally with my T-25 and an HKS EVC original and it never spiked or did anything. It's all in the boost controller really.

Key words: o2 eliminator. If he uses the stock o2 housing, it WILL creep. Even with a ported 1G housing, it'll probably still creep. You'd need either an EVO o2 housing, o2 dump, or o2 elim. to get rid of creep on full catless 3". Speaking of catless, it's absolutely disturbing how many people here have no clue that only 2G cars have the rear o2 sensor/CEL issues

 

[kicker91laser]

go to www.vfaq.com, look on there, they have some info and pics on porting, or just look at some of the dsm shop's port jobs, its pretty easy to do, be sure to get some carbide burrs

 

[daren_p]

I was wondering if any of you could direct me towards a link or some pics that show the porting of the o2 housing, turbo inlet, and wastegate passage. Something that shows clear pictures so I have a good idea of what to do.

http://www.vfaq.com/index-main.html

Good source for porting plus many of the other common dsm mods, everyone with a dsm should know about/read this.

Edit: kicker91laser just beat me

 

[karbon]

Can anyone recommend a good muffler to mate to a 3" turbo back, not insanely loud, just a nice deep sound you know? None of that angry bumble bee honda bullshit . (Is that sound even possible out of out cars? )

Thanks

Wayne

I personally love my Thermal Research exhaust (with the RRE resonator). It sounds deep, it sounds mean, and the best part is that the pipe actually points out the back of the car, not angled out the back like most exhausts.
Here's a start:
Deepest Sounding Catback Exhaust???

 

[peregrine]

i had a full 3" o2 eliminator on my 14b awd and the car ran 13.2@101 at 4500 ft. its not too big. i had no creep issues. of course i never had a boost controller. i just screwed around with some restrictors in the signal line. used to confuse everyone when id run 20 psi without a BC.

 

[Bailzz]

I hate hearing about everyone recommending there exhaust which is on a 2nd gen when the person asking has a 1G. Thermal research sounds great ! But who offers it for 1G? Most 1G guys will recommend Apexi N1 hands down