Flex piece in downpipe needed?

[JoeyJigglesGSX]

hey i was just wondering, i had a custom made exhaust and back then i didn't really know much last year so i never said anything about the flex piece in the downpipe... the question is this...

how important is that? do i really need it?

 

[1fast97gsx]

Not really needed ... I don't have one either. If the exhaust isn't PERFECT fit though and you hit a few bumps on the road or hard shifts with bad motor mounts there's a chance the welds around the flanges may begin to crack over time.

 

[Syndicate13]

I don't have one either. The exhaust is held on by rubber hangers so there is some flex in the system anyway. I've been running my exhaust for 2 years and never had a problem, well, except setting off car alarms everywhere I go.

 

[boostedinaz]

It mostly depends on how bad your motor mounts are. If they are shot your exhaust will break, if they are in dcent shape you should be ok. I persoanlly would just put it in, better safe than sorry.

 

[DSMJim]

I had a housing crack on a turbo on my old car because it didn't have a flex section in the exhaust. Motor mounts or not, the motor swings around a lot in the engine bay (Take your hood off and drive to see it.) and if you don't have a flex your putting a lot of stress on stuff. If you have just the right amount of torque and the motor swings and the exhaust doens't break (a hollow pipe is VERY strong) something is gonna crack. So on my car is cracked the casting on the exhaust housing of my turbo. That sucked.

 

[Goodguy162000]

Yes, I'd say it's a very good investment. Think of it like this. Everybody now-a-days has a turbo timer it seems. Why? To prolong their turbo. Why wouldn't you do the same for your exhaust and motor mounts?

 

[JoeyJigglesGSX]

yeah you guys are right...anyway i have to get a new downpipe...i just spent over 2,000 grand for a new turbo and porting everything out to get away from boost creep and it turns out the reason why i cant control this boost is because of my ### ass downpipe...so the shop is helping me out and i guess i will be getting the A'Pexi downpipe to put some back pressure and have that flex piece...thanks for all of your responses

 

[boostedinaz]

yeah you guys are right...anyway i have to get a new downpipe...i just spent over 2,000 grand for a new turbo and porting everything out to get away from boost creep and it turns out the reason why i cant control this boost is because of my ### ass downpipe...so the shop is helping me out and i guess i will be getting the A'Pexi downpipe to put some back pressure and have that flex piece...thanks for all of your responses

So they are putting a bandaid on the problem and not actually fixing it, all the while decreasing the performance of you car. Great shop.

 

[JoeyJigglesGSX]

So they are putting a bandaid on the problem and not actually fixing it, all the while decreasing the performance of you car. Great shop.

well what do you think i should do then?

 

[1fast97gsx]

...i just spent over 2,000 grand for a new turbo and porting everything

Wow $2,000,000 is a lot of money for a turbo and a port job. You got hosed.

 

[JoeyJigglesGSX]

well it was including all installation also...it wasn't bad

 

[JoeyJigglesGSX]

...wow im out of it today

 

[boostedinaz]

well what do you think i should do then?

If it is a boost creep problem then I would look around and the million threads about it and see how others have cured the problem and try them out. If nothing works then I would go with an external WG setup. I find it horrible that a "performance shop" is telling you to add back pressure to get rid of creep instead of doing more porting or looking to see if they can find numerous other solutions.

 

[JoeyJigglesGSX]

i know this whole situation sucks for me...he is taking the o2 housing back off and port it out even more and see what happens...but i need that flex piece in there anyway...i dont know

 

[illeagle_talon]

Boostedinaz is correct. Adding back pressure is just going to cripple you. Go the tried and true way to correct boost creep. Either port the hell out of your O2 housing, get a larger wastegate flapper, or just do the easy thing: get an external dump housing!! If you're still worried I suppose you could just get an external wastegate.

-Cam

 

[boostedinaz]

i know this whole situation sucks for me...he is taking the o2 housing back off and port it out even more and see what happens...but i need that flex piece in there anyway...i dont know

What about porting the turbine housing? It was mentioned to put an external dump but that, in it self, wont cure creep. You need to make sure that the WG passage can flow enough to not creep.

Take it to a real shop, not Bubbas Chicken and Turbos.

 

[JoeyJigglesGSX]

i have had everything ported...i have the 34mm flapper door, o2 housing, and exhaust manifold all ported out...i used to have the external dump, but that didn't do anything and i didn't like the sound of it anymore so that is why im going with the ported o2 housing...but honestly how much can just 12" of downpipe that is 2.5" be that much of a cripple? the most i would ever run on this car would be about 18 psi

 

[boostedinaz]

i have had everything ported...i have the 34mm flapper door, o2 housing, and exhaust manifold all ported out...i used to have the external dump, but that didn't do anything and i didn't like the sound of it anymore so that is why im going with the ported o2 housing...but honestly how much can just 12" of downpipe that is 2.5" be that much of a cripple? the most i would ever run on this car would be about 18 psi

Perhaps the shop that did it either didn't do a good enough job or they haven't ported the WG passage enough. This is what they really need to spend time on not just making the entire housing bigger. Your other option is to get an external WG, but that can be pricey. You can go right ahead and just put some restriction in your exhaust if you want, but just know that it wont actually fix the problem and it will slow you down. How much is impossible to say.

 

[JoeyJigglesGSX]

here is an update for anyone that cares...

well they ported out the o2 housing more. Did some porting on the turbo it was something that the guys that make the turbo told him to do, and even added in the first 14" of downpipe to be 2.5" and still didn't hold the boost. What it comes down to is that because i was cheap when i first got the car and had my friends cousin who owns a repctable exhaust place just make me a exhaust system. There is only 1 bend and then it goes straight out the back compared to other GSX exhaust systems that have 2 or 3 bends. My tech. told me he was going to do some more things and if that doesn't work, based on my budget i will be going with the 3" downpipe and a high-flow cat...i guess we will see what happens

 

[SethA]

There was a thread that got locked (I think it was toward the end of last year) about repostioning the rod from the wastegate actuator closer to the pivot point on the wastegate arm. This would in theory allow the flapper to open further allowing more wastegate flow and therefore hold lower boost. I remember some people tried it and it seemed to work. Maybe you could try this before buying a cat.

Seth

 

[boostedinaz]

here is an update for anyone that cares...

well they ported out the o2 housing more. Did some porting on the turbo it was something that the guys that make the turbo told him to do, and even added in the first 14" of downpipe to be 2.5" and still didn't hold the boost. What it comes down to is that because i was cheap when i first got the car and had my friends cousin who owns a repctable exhaust place just make me a exhaust system. There is only 1 bend and then it goes straight out the back compared to other GSX exhaust systems that have 2 or 3 bends. My tech. told me he was going to do some more things and if that doesn't work, based on my budget i will be going with the 3" downpipe and a high-flow cat...i guess we will see what happens

There are conflicting ideas in you post. The less bends the better so i would stick with that. If you really want to go 3 inch i say go for it, but I have a feeling it will make you problem worse. You keep saying they are porting out more and more, but you arent saying were. Did they port out the WG passage itself?

 

[JoeyJigglesGSX]

There are conflicting ideas in you post. The less bends the better so i would stick with that. If you really want to go 3 inch i say go for it, but I have a feeling it will make you problem worse. You keep saying they are porting out more and more, but you arent saying were. Did they port out the WG passage itself?

yeah i understand the less bends the better but with 3" exhaust and only wanting to run like a max of 18 psi on the street, there really is no need for it being "that" straight. The exhaust is just too free flowing for my set up is what i am trying to say. If i was running like 25-30 psi then everything would be cool. I just want my set up to work basically. When i had everything done, everything was ported. And yes the WG passage was ported also. When i say they keep porting i mean that they are taking off everything again and just making sure everything was done right and touching up some areas, kind of pushing the limits with everything to help it out which it is, just not completly stopping it. I think he said that he has it pretty much controlled to 3-4 psi it would spike. Don't quote me on that yet. Just from what i understand he was saying. I'll post another up when after i talk to him around 6:30

 

[boostedinaz]

yeah i understand the less bends the better but with 3" exhaust and only wanting to run like a max of 18 psi on the street, there really is no need for it being "that" straight. The exhaust is just too free flowing for my set up is what i am trying to say. If i was running like 25-30 psi then everything would be cool. I just want my set up to work basically. When i had everything done, everything was ported. And yes the WG passage was ported also. When i say they keep porting i mean that they are taking off everything again and just making sure everything was done right and touching up some areas, kind of pushing the limits with everything to help it out which it is, just not completly stopping it. I think he said that he has it pretty much controlled to 3-4 psi it would spike. Don't quote me on that yet. Just from what i understand he was saying. I'll post another up when after i talk to him around 6:30

Im not sure if you are going by what they are telling you or if you are just getting your info from a different source. Either way, you want the least amount of restriction no matter what PSI you are going to run. In fact the best exhaust for a turbo car is no exhaust at all. Now that wont work with a street driven car, but you get my point. It sounds to me like you may need to step up to an external WG setup.

 

[JoeyJigglesGSX]

Im not sure if you are going by what they are telling you or if you are just getting your info from a different source. Either way, you want the least amount of restriction no matter what PSI you are going to run. In fact the best exhaust for a turbo car is no exhaust at all. Now that wont work with a street driven car, but you get my point. It sounds to me like you may need to step up to an external WG setup.

yeah well i guess one day i am going to have do the external wastegate. Just why is it me who has to deal with all of this stuff and not have my car just work right? Just sucks i had to spend all of this money and really get nothing out of it because i am not going to be able to afford the wastegate for right now...anyway, thanks for all of your posts

 

[boostedinaz]

yeah well i guess one day i am going to have do the external wastegate. Just why is it me who has to deal with all of this stuff and not have my car just work right? Just sucks i had to spend all of this money and really get nothing out of it because i am not going to be able to afford the wastegate for right now...anyway, thanks for all of your posts

Dont let it get you down, it is just the way car things go. I was pumped about my Shep tranny, then my motor cashed out the #2 piston so I had to have it rebuilt. Just look at it as a time to make things better, and not a ####ed up deal.