Hey guys,

I recently picked up a set of Fabspeed straight pipes for my 996TT, which already has a tune. Obviously these are for off-road use only...so no issues there.

However, considering that my car has a Gemballa tune and a stock exhaust (I consistently hit 1.0 bar on the factory boost gauge in higher gears), I have some reservations about bolting on the straight pipes without getting a re-tune. My question is essentially how will the car run under boost with a normal tune and straight pipes?

With my previous turbocharged cars, the factory computer would still keep things reasonably safe even without cats, so it wasn't a huge problem. However, I cannot afford to take a gamble on this with the engine in my Porsche, so if being prudent and getting a re-tune are the smart and safe things to do, I can certainly wait for later to do this mod.

I do have a Durametric, so resetting error codes isn't a big issue for me. The Fabspeed pipes do have bungs for the O2 sensors, so keeping those in play isn't a problem either. However, my real concern is that I cannot currently monitor A/F, so I want to make sure that putting them on the car and driving it isn't going to be unreasonably dangerous.

Anyone with real world experience or relevant tuning advice is welcome. This would be the first significant modification that I've purchased for my car in over 2.5 years so I do want to be intelligent about it. Thanks in advance!

 

Your rear O2's will likely throw a check engine light, you can have your tuner disable the rear O2's, or could try some of those adapters that move your O2's out of the stream a bit, not sure how effective the adapters are long term, maybe others will chime in.

Outside of that you should be ok, install them, reset ecu by unplugging the battery. Your tune should adapt fine to the straight pipes, you could do a third gear pull and log boost and front O2's with your durametric, just to make sure everything checks out.

 

HI,All I can tell you is that when I went from a 200 cell Cargraphics system to a Milltek 100 cell system, in which the Milltek mufflers were alot more free flowing also....I picked up about .15 bars and was running out of fuel with my original EPL tune for the Cargraphics,,then I had to add an extra fuel pump to supply the injectors and EPL retuned it to take advantage of that,, in which I made more power then........Good Luck

 

Thank you for your reply JSBear. I've never used my durametric for logging while driving before, but that's obviously very sound advice...and gives me a chance to fool around with that software, which is also fun. I appreciate knowing that this should be reasonably safe.

Hey johnspeed. I appreciate your reply and it certainly gives me moment for extra consideration of course. My own car is a K16 turbo setup (not K24 like it appears yours is by your signature). I suspect that the boost levels might go up a bit as a result of going from the most restrictive exhaust (stock) to the least (straight pipes), so that is even more reason to be cautious and do some durametric logging to know what's going on with the setup. I suspect that our considerably different setups (mine being much closer to stock) might have bearing on the outcome, but I'm not sure how many mods you had when you experienced what you did. Thanks!

 

UMW is in your backyard.... what, 30 minutes away? In my mind that defines the perfect tuner.

kevin would surely give you his input (ie tell you what to log, how to log, and send it to him) and let you know what to do next. Will it necessarily be a new tune? Dunno, but given your caution, I would wholeheartedly recommend UMW for that kind of person.


GL

A

 

I've chatted with Kevin before, when I first bought my car 2.5 years ago. First off, he's a very kind and informative guy. One thing he told me that really blew me away was that he thought my existing (Gemballa) tune was totally adequate for my mods. Had he wanted to, he could have *easily* told me that he could make huge gains for me with just a tune (or whatever someone would want to say) but he was super honest and said for a car with minimal mods, that I'd be totally fine with my current tune. So, I have a high opinion of the guy. I'll drop him a line though, that's good feedback. Thanks!

 

Should be fine on K16's, however, it's always wise to log to be sure, just so you know you are in a safe range. Better yet, do a baseline log as is, then again after ... 2k to redline in third gear. You can compare O2 voltages, if your running leaner with the straight pipes, you will see it, as the O2 readings will be LOWER.

I assume you are on pump fuel ? 93 ?

 

I fully agree about the logging, and I'll do a before/after 2nd/3rd gear pull as that sounds like a smart idea for sure. Yes, pump gas (92 octane) is what I run.

I did approach Kevin at UMW, and explained the situation similarly to my original post in this thread. Here was his short but succinct reply to me, which obviously helps to put my mind at ease: