1G Exhaust questions

[Bigmike4g63t]

I finally got a nice gsx after some years of wanting. My local exhaust shop will be fabricating the exhaust except for me supplying the downpipe. Should I have a bung welded in and just cap it off until I install a wideband and ecmlink 3?

 

[slugsgomoo]

I would- it will be cheaper to do now, and it'll be convenient.

Be sure that they are aware of the correct orientation to ensure good sensor life. Most wideband units have a spec for distance from the turbine outlet, and the angle to install (the last one I did I want to say was ~18" after the turbine outlet, and they wanted the sensor installed at around 45* so that any condensation after cool down would drain out into the exhaust, versus pooling in the sensor itself.

 

[Bigmike4g63t]

Another question.

My new exhaust will be 3in all the way back with no cat. will that change where the wideband goes? Also to not have a CEL should I retain O2 sensors or can I program that to compensate with the ECMLink?

I don't guess it would be a bad idea to go ahead and get the ECMLink even though it is stock for now would it?

 

[Vegas Smith]

You can run a totally stock tune with ecmlink. Not having a cat will not change where the wideband goes. Some people run the wideband right under the shifter so they can route it right into the cabin to the ecu for convenience. Some people run the widebands right off the turbo but it's controversial.

 

[Bigmike4g63t]

Will not having o2 sensors affect the readings of the ecmlink?

 

[Vegas Smith]

Yeah your car basically won’t run.

 

[slugsgomoo]

Please fill out your profile to detail what car you're working with and any mods-

If you have a 1g, there's only a front o2 sensor- keep it in the o2 housing, and delete the cat to your hearts content, put the wideband where it goes based on the manufacturer spec.

If you have a 2g, getting ecmlink makes it easy to delete the rear o2 (since you'll have a check engine light), however if you aren't ready to do ecmlink yet, something like this https://www.racdyn-usa.com/PROD/130+10+10+010.html might solve your check light with the rear o2... just saying

 

[Bigmike4g63t]

I was waiting to fill my profile out after actually picking the car up. I did that on Wednesday. My downpipe came in yesterday. On Monday I am getting the o2 bung welded into it and then on Friday it is going to the exhaust shop. I bought as close to stock looking muffler as I could find with the exception of the 3" inlet and dual 3" outlets.

Do people still port and polish the 1g exhaust manifolds or buy a 2g and do them? Would probably be easier to just buy another manifold, o2 housing and turbo housing to gasket port and polish and smooth the ridges out of the inside to keep the car from being down while I do the work. Or is there a better way these days. The last eclipse I had that I done this type work on was nearly 20 years ago. I have had one Talon AWD since then but I left it stock.

 

[Spleen8urLSX]

Still the way to go on a 20g or smaller turbo. However while the 2g manifold was much less susceptible to cracking than the 1g manifold unfortunately age is finally getting to them and they are starting to crack. The solution, there’s a reproduction 2g replacement exhaust manifold sold under the Dorman name and a few other names for a pretty reasonable price, a few have had good luck porting these and running these. They can be had from rockauto as well as the chain stores (AutoZone, Oreilys, etc) however rockauto is likely going to have a better price.

Before someone says it, the Forced Performance race manifold is an awesome cast piece with a stock flange and stock location for under $300 that wouldn’t require any porting, however it’s large runner design is geared towards large frame bolt on turbos like the FP Red and black, etc. Its not the most optimal choice for something like a 14b or 16g with that being said, however, if you’re not looking to squeeze every bit out of it and don’t care to spool 400ish rpm later than the ported 2g manifold, it’s something to consider.

Another thing, in the time you’ve been on a hiatus Chinese knockoff 16g’s and td05 20g’s have gone around like wildfire. While most of these don’t live past 10k miles (many don’t even make it 5k) they did have 7cm turbine housings and adjustable wastegate actuators that are pretty decent with a little work. With a bunch of blown Chinese 16g’s out there this means these 7cm turbine housings and matching hate actuator are easily available for a fair price. The flaw with the turbine housings is while they actually utilize a significantly larger wastegate flapper than their true MHI counterparts the wastegate passage itself is tiny and requires some port work if you plan to run lower boost and not fight creep, if you plan to run higher boost of course that’s not an issue, but if it is it’s nothing some porting can’t take care of. On the plus side they’re cheap, they’re casted more open than a real MHI 7cm turbine housing (example the lip for the fire ring isn’t present), and they’re a direct bolt on upgrade for the 14b that we can almost guarantee has a crack or several in the original 6cm housing. With that being said even if you need to port the wastegate passage no further porting is needed.

Figured that’s worth mentioning as wether you choose to port a reproduction manifold or pick up an FP manifold, it’s a good time to upgrade while you’re doing that along with porting your o2 housing. Also keep in mind to steer clear of the cheap tubular manifolds and o2 housings that are all over the place, the manifolds don’t flow anywhere near as well the ported 2g or FP job and the thin material is prone to cracking, same with the o2 housings, a ported stock o2 housing will flow better and theyre made from the same crappy thin material that’s prone to crack. The cheap manifolds are great for those looking to run a big t3 framed turbo on a budget and know the risks, but no point for a bolt on turbo when reliable options are available for a good price and a little port work.

I also seen you mentioning the o2 bung and ecmlink in another post, keep in mind once you get your exhaust on with the bung you can go ahead and put the wideband on it, no need for ecmlink or any other engine management to use the wideband. No harm in being able to monitor the air fuel ratio on a stock car with just bolt ons until you make the move to ecmlink. Hope the insight helps out! Glad to see the old school guys coming back and asking good questions like this.