jeremyb

I tried searching for this exact quote of what the subject name is... I didn't get anywhere, I found a few but none that I was looking for . I KNOW there's an article about this somewhere lol. I know people have 3" DPs on their stock midpipes... But the guy that I bought my SS DP from (he says he thinks its pettits), says that I will need a 3" Midpipe to accomodate with the DP. Is this true? The DP was not cut and repositioned in anyway sooooo.... IM STUCK! Can this dp fit my stock midpipe or will I need a 3" midpipe? Thx for the 2 cents guys..

Jeremy

novadan67

If the downpipe was designed properly it will fit with your stock "midpipe" (actually it is a cat). Some of the cheap downpipes from Ebay have been known to have fitment issues with the stock cat. I have an m2 downpipe and it fits great.

dgeesaman

iTrader: (7)

Yep, that's the consensus.

The cheaper downpipes won't fit with the stock cat, but will fit with the midpipe they sell with. I had one from RX7Store that was sold alone and didn't fit my stock cat - but they made a quick return and sent a Pettit one instead (which fits pretty well). The problem with that one is the flange was bent and the holes weren't spaced right. So get a good quality one (used from here) and you'll be fine.

Dave

jeremyb

well i hope the DP this guy sends me is a good quality one. He says its pettits but hes not sure -_-.

Jeremy

jeremyb

So theres no way at all to get this to fit? The flanges don't line up at all? or is it just the flange holes? Is it possible to drill open the holes?

Jeremy

GVilleTuner

Its probably best to just get the 3'' midpipe

jeremyb

Ok... I probably will then... but another question now! How do I know what will fit this DP? AND!!!... Will this midpipe I buy go on the stock catback exhaust? Im planning on running a cutout and really do not want to buy a 3" catback .

Jeremy

JaNusSolSumnus

I have the ebay DP and MP and other than the bolts at the turbos being a tight fit everything worked great with the stock main cat. I just fitted the MP tonight and it came together nicely... havent had a chance to hear it yet, weather isnt permitting me to bleed the clutch so I can start the car.

~Kris

alberto_mg

You won't know till you get it

If you take it to a decent Rotary place or other qualified exhaust place to install it they can enlarge the holes so that it fits the stock cat. I had to do that with my downpipe (brand unknown).

As for midpipe, you don't want to install one unless you have a boost controller as you'll wind up running too much boost and blow your motor. Do some research on that.

pugg57

i bought an RX7Store dp and had the boys at the shop where i work slot the holes out .25" to the outside and it fit perfectly

jeremyb

Kris, I wanted to do what you did but heard bad with fitment issues SO CHEAP TOO!. It hurts me to know that everything worked out for you and I could be where you are instead of where I am now lol.

Alberto, I can drill the holes out my self if thats what's needed, I'll need a gasket right? As for running a boost controller, I have considered that since I will be running an open cutout from the mid pipe. I have a PFC and will get tuned once all this stuff gets installed. I'm still deciding on whether to run a MBC or not.

Jeremy

dgeesaman

iTrader: (7)

Mine also had a bent flange, and no 'boys at the shop'. I was very disappointed with it.

Dave

pugg57

oh yeah, let me add that mine was second hand also, so i dont' think it would have been for sale if it had had issues to begin with. i wasn't downing ya or doubting ya, i just was adding my $.02 that i had to have it "fixed" too.

JaNusSolSumnus

Yea, I know what you mean, I was just willing to take the chance for the price.

It did take some modification at the turbos only because of the pipe's shape.. it is good and bad. It was good because unlike the HKS DP there is no kinking, it is all mandrel bends. The bad was that I had to gride down the bolt head's 'built-in washers' and trim one of the studs down in size to make installation/removal less of a hassle.

However when it came to the stock cat it matted up perfectly using the stock bolts.

~Kris

jeremyb

Well I pretty much know I'll have to be doing some slight mods to make things easier later on. And yes I love mandrel bends lol. I do hope I get this to line up with the stock cat though =/. I'm planning on running a cutout and REALLY do not want a midpipe for no reason. By any chance does anyknow know the dia. for the stock exhaust piping?

Dave, the DP with the bent flange... was this Rx7store's?

Jeremy

jeremyb

Ttt