Hello,

I have a few questions in regards to down pipe upgrade that is available for 335 owners.

First off, how many people actually have a down pipe upgrade ?
(Please vote not interested if you already have a down pipe upgrade!)

Second, how many people are actually interested in getting this in the future?

Third, how many people are willing to buy it right away if it was being sold at reasonable price?

Thank you for taking your time to answer these questions, I am just testing waters to see if it would be big enough for ...

Thanks,
Robert.

Once you start with a DP upgrade,be prepared to be spending a lot more money on more upgrades.After you do a DP with performance cats,you,ll have to do a cat back performance exhaust to get the full benefits out of the DP. Which is called a turbo back exhaust.(performance exh. from the turbo,s back out the rear bumper. Then you,ll want to do an intake to make it breath easier for that TB exhaust. Then its into the ECU to extract the most power from your mods,like boost,A/F ratio,s,fuel timing,etc.,etc. Once you start modding it becomes an addiction.Believe me i know what i,m talking about. Being 50 and having many high per. cars from muscle cars,to tuner cars,and everything in between i wish i had a dollar for everytime i,ve said i,m leaving it stock,or just doing this or that and thats it.Its one helluva expensive hobby,which i,m sure you all know. I remember when i got my first new Evo in 03. I swore i was just gonna do a K&N drop in, and an ECU flash.Well 5 months later and 5k dollars,well you know.

You'd have to show some power increase before anyone's going to say their interested.

Once you start with a DP upgrade,be prepared to be spending a lot more money on more upgrades.After you do a DP with performance cats,you,ll have to do a cat back performance exhaust to get the full benefits out of the DP. Which is called a turbo back exhaust.(performance exh. from the turbo,s back out the rear bumper. Then you,ll want to do an intake to make it breath easier for that TB exhaust. Then its into the ECU to extract the most power from your mods,like boost,A/F ratio,s,fuel timing,etc.,etc. Once you start modding it becomes an addiction.Believe me i know what i,m talking about. Being 50 and having many high per. cars from muscle cars,to tuner cars,and everything in between i wish i had a dollar for everytime i,ve said i,m leaving it stock,or just doing this or that and thats it.Its one helluva expensive hobby,which i,m sure you all know. I remember when i got my first new Evo in 03. I swore i was just gonna do a K&N drop in, and an ECU flash.Well 5 months later and 5k dollars,well you know.

Although you're absolutly right, and there is a mod bug, putting DP's on a 335 will give you signifigant gains alone. You honestly dont have to put racing cats or the rest of the exhaust... its not like the rest of the exhaust will add much more, its the DP's that really shine.

well from what i've read on e90post they speculate close to 400rwhp with procede v2, and DP

well from what i've read on e90post they speculate close to 400rwhp with procede v2, and DP

Nope, infact there were minimal gains on a dyno with a car that had a catback exhaust, Procede v2.0 (custom tune) and catless downpipes over the same setup with stock downpipes. While the turbos spooled a little faster there wasn't much hp/tq gains. I don't remember everything in the thread, however there was speculation that the limitation was either the intake or the turbos.

And to the OP, are your gains estimations or real numbers? I assume the numbers are over stock, which may not hold true on a modified car. Other companies have already released downpipes with similar gains over stock, however there has been several occasions with people utilizing different piggybacks, exhausts, etc combos with little to no gain over their current setup. I would assume that if someone is going to upgrade their downpipes, changing their exhaust and adding a piggyback is pretty common place, so it would be nice to see results with a common "tuner" application with a piggyback of your choice and a free flowing exhaust at a minimum.

coming from other turbo'd cars i find it fascinating that dp's arent the first mod(after EM) that owners are doing. getting the cats immediately after the turbo out opens up huge gains.

i've only owned my 335i for less than a week but i still dont understand this.

There are gains there, maybe 10-15rwhp. Some people just have unrealistic goals with the DPs.

There are gains there, maybe 10-15rwhp. Some people just have unrealistic goals with the DPs.


Post a link to someone seeing gains with a piggy back and downpipes, that has not had their intake or turbos upgraded.

coming from other turbo'd cars i find it fascinating that dp's arent the first mod(after EM) that owners are doing. getting the cats immediately after the turbo out opens up huge gains.

i've only owned my 335i for less than a week but i still dont understand this.


I agree that on most turbo applications you see gains, apparently the intake and turbos on the 335i are not able to deal with the increased flow. I have not done a lot of research, but there are a few people on e90post with custom tunes (AA and Vishnu), piggy backs, exhausts and their dynos do not show any gains.

Post a link to someone seeing gains with a piggy back and downpipes, that has not had their intake or turbos upgraded.

No 335i has upgraded turbos or intake. There a few out there showing 8-12rwhp if you look. When I get my set I'll do a dyno and post.

No 335i has upgraded turbos or intake. There a few out there showing 8-12rwhp if you look. When I get my set I'll do a dyno and post.


Actually there is; BavDom/VQmtuning has a stage 2 intake out for the 335i and RDSport has a turbo upgrade package. I have looked at all the threads were people are running catless/catted aftermarket downpipes, free flow exhausts and piggy backs and none have shown any gains. Please link one that shows gains, and I don't mean over a completely stock setup.

Thanks.

Actually there is; BavDom/VQmtuning has a stage 2 intake out for the 335i and RDSport has a turbo upgrade package. I have looked at all the threads were people are running catless/catted aftermarket downpipes, free flow exhausts and piggy backs and none have shown any gains. Please link one that shows gains, and I don't mean over a completely stock setup.

Thanks.

I really have no vested interest in proving to you that downpipes will or won't help, but I'm comfortable with my 10-15rwhp estimate. I'll let you know after I have them installed!

I'm waiting to see RD sport dynos or intake dynos that show gains too. So far, nothing that impressive.

I really have no vested interest in proving to you that downpipes will or won't help, but I'm comfortable with my 10-15rwhp estimate. I'll let you know after I have them installed!

I'm waiting to see RD sport dynos or intake dynos that show gains too. So far, nothing that impressive.

Sorry didn't know it would be that hard to post a link. I guess your "estimate" is as good as it gets and its better than what people are actually seeing.

Sorry didn't know it would be that hard to post a link. I guess your "estimate" is as good as it gets and its better than what people are actually seeing.

It's easy enough, but not everyone posts all their data. Here is a link from HP Autowerks, they show a 9rwhp gain with their 2.5" downpipes on an otherwise stock car:

http://www.bimmerfest.com/forums/showpost.php?p=2563426&postcount=98

It looked like a e90post member saw 5rwhp/15rwtq running the stock downpipes with empty cats:

http://www.e90post.com/forums/showthread.php?t=86880

I am expecting 10+rwhp /10rwtq out of nice 3" downpipes. There might be more there, but I'll find out soon enough!