I'm purchasing a down pipe shortly and am considering either Pettit's or M2's. I like M2's because their's doesn't require removal of the studs. What do you you guys think?

 

M2, simply because of that reason.

 

all DP's are pretty much the same just make sure that you are gettin stainless steel and not mild steel.

i would go for the m2 as well.
thats if they have them in stock.
there parts are always on backorder.

 

I found when doing my DP install that two or three of the studs came out when removing the nuts anyway. If I had to do it over again, I think I would get the HKS and get it jet coated. I'm just saying HKS becuase you know it will fit. I think its cast where as the others are mendral bent pipes. At least I think so. Someone please correct me if I'm wrong. Looking at the HKS one I don't think it requires removal of the studs either. I could be wrong though.

 

I have an RX-7 Fashion DP. Might want to check that one out too. 3 of my studs came out on me while I was doing the install as well. This is a VERY nice pipe has a HUGE radius on the bend coming off of the turbo and it has a good O2 sensor placement (something else to consider) as I have seen some other DP that have the O2 sensor in stupid places. One DP I saw had the O2 sensor coming out at such an angle that it hit the side of the engine bay and the end of it had to be bend so it would fit.

 

I have the Pettit SS downpipe, and it is a very good unit. The installation was totally anti-climatic....I was expecting HELL and...it was no big deal. Hell, the rear brakes are harder to do!
Just presoak the studs and any other bolt you will be taking off with Liquid Wrench for a few hours. I feel this is absolutely necessary.

Good luck!

 

I would go with the HKS. It has a cast manifold, puts the O2 sensor in stock location and is very reasonably priced. Got mine from Dynamic Turbo. Use plenty of PB Blaster on the nuts before removal, studs may come off with nuts. If so, get two metric nuts that fit studs and lock them together to remove lock nut from stud. When re-assembling things USE anti-seize!

 

I would get the rx7fashion or the m2... I have the rx7fashion dp and it's great. and I know they have them in stock, because I was there a few days ago...bunch hanging on the wall..

HKS is a POS.. sorry.. I know it's cheaper..but cast...weird ugly bends.. yah yah I know it's under the car...but it hangs lower then normal dp too..

 

I have HKS, no need to remove studs, and best price around if you get if from Jason.

 

I got the ATR SS downpipe and Midpipe for 380 bucks. Thats for Both in Staninless steel. It fit great and the 02 sensor is so easy to reach now!! Also it has lots of room to use any 02 sensor. The RX-7 Fashion Pipe requires you use the stock sensor because of clearance issues. For price, Fit and ease get the ATR. Most places sell it for 350 bucks just for the downpipe. I got my DP and MP for 380 from Chris at horsepowerfreaks.com

 

I could be wrong but that was a first run issue..corrected many years ago...

 

M2 - The HKS uses the same casting as the stock precat at the mounting flange and is only 2.75" vs full 3" for the M2 unit. My M2 unit had much cleaner welds, smoother bends, much greater ID (at least 1/4") and a thicker flange at the cat end than the HKS unit I compared it to. Whatever pipe you get have it wrapped w/ ThermoTec Wrap - I can touch the outside of the ThermoTec barehanded when the exposed portion of the flange is hot enough to instantly sear flesh - A purely unintentional test on my part I assure you and I have the scar on my wrist to prove it!

 

Yeah they must have changed it. Mine has plenty of room for a different brand of sensor.

 

M2 from what I hear is one of the better ones. I bought M2 but have never owned another one so I really can't personally compare. But the M2, for me, was pretty easy and everything about the pipe is very sweet.

 

I was about to get the SR Motorsports DP because it is 3" and they will tig weld an EGT before shipping so I won't have to drill for the EGT guage install. I don't know about the O2 sensor, will have to ask.

Jet coat can order it if you buy from them and you save one shipping charge.

Has anyone else used the SR DP?