downpipe install from hell
 

ok so i decided to be cheap and get the ebay dp for only $90. it came w/ a midpipe as well, but i cant use it b/c of emissions. im not really mechaniclly savvy but i figure its only six bolts, it cant take that long. hehe... i was wrong. 1 of the 4 bolts on the manifold was redicolusly hard to get to, the top bolt towards the back of the car. got the bottom two from under the car, using a wrench since a socket wouldnt fit. it only took about 500 turns moving about 2 inches each turn. the top bolt in the front of the car was the only 1 that was not that hard. (thanks to pb blaster) however this last bolt did not want to come out. couldnt be reached w/ a wrench or regular socket. i didnt have deep sockets so i had to use an extension, but the extension was so long that the socket wrench was aginst the side of the body. needless to say, that bolt took a while as well. then on the the cat bolts. i almost knocked my car off the jackstands trying to get those bastards off. rust sux! finally i was able to pull the precat out by this time it was dark, so i had to wait until the next day to finish. after my 6hrs of hard work, i went out and had a few drinks, and ended up getting trashed and not waking up until 3pm. :dammit: btw my car is at my parents house (which is 1 hr. away) b/c my stupid apartment wont let me work on my car in the parking lot. get there around 5pm and its getting close to dark. get the dp up under the car, and try to start lining up the bolts. i get 1 lower 1 in, but cant get the other. then i tryed taking the bottom 1 out, and starting from the top. then i couldnt get the bottom ones in. the mother f-ing holes are not lining up. its dark now, and i have to wait another day, but i have to work also. i get up earily to work on it before work, i whip out the dremel and start working on one of the holes. finally after 2 hrs of dremeling i get the bolts to line up. but i cant get a bolt on the last hole thats up top. so i tighten 3 of them but i now discover that the bolts that came w/ the dp are to long for the holes in the manifold. WTF!! i said screw it and just tightened them as far theyed go. back to the cat bolts. apparently the bolts on the dp are only ment to fit the damn midpipe. out comes the dremel again. 3hrs later i have the dp on the cat. i didnt have anymore time b/c i had to go to work, so i decided to crank it and see what happens. i now have a huge exhaust leak by the manifold. so i have to wait until tomm to get shorter bolts and hope i can somehow get the 4th bolt on. i may have to remove the abs or the y-pipe to get to it though. i cant wait to see what problems i run into tomm.

That's why the M2 is rated best because it fits. Pettit comes with new replacement bolts. Tri-point is supposed to work well. All of those are $300-$400. You are also supposed to replace the gaskey and the crush nuts. There's tons of horror stories uncluding one guy that paid $1k because of broken studs.

Damn sounds like a bitch, I hope I don’t have that many problems with my dp, that will be here on Wednesday.

I learned the hard way that it's better to buy used name brand dp (Pettit, M2, Bonez, etc) than a new cheap ass knock-off.

Do not overtighten the bolts going into the housing. You will either snap them off or crack the housing.

I ended up with a used Bonez DP and was able to use the factory studs for 3 of the 4 holes. The 4th hole required an M10x1.5" socket head allen bolt that was 25mm long.

Sonny

hope you didnt get the one of ebay. i agree w/ sonny, i wish i would of spent the extra money and saved probablly 2 days of work.

I've heard of fitment problems with almost all downpipes at one time or another...I was amazed how easy my stock precat came out, the bolts were easy to access about a 10 min soak with pblaster. Did you remove the heat shield for the abs? I don't have many tools at all...but everything went smooth for me...good luck! :)

SNracing, did you buy brand new gaskets, or did you reuse the old ones?

Also, which direction did the holes need to be ground out? Further out from the center, or closer to the center? I'm assuming you're referring to these holes: https://www.rx7club.com/attachment.p...postid=2757342

-s-

i had to drill outwards, and a little upwards on one side. and yea, its the holes on the flange that bolts up to the cat.

my buddies bolted up fine. He uses the dp and i bought the mp. It is a bitch due to the bolts being old and soaked in heat for so many years......Soak them all in PB Blatser wait 15 minutes do it again...Honestly when I couldnt get of the manifold bolts out I would spray them...drink a beer...spray them..drink a beer..spray them..drink a beer...By then I was tanked and they were loose.. SWEET

Yeah its and Ebayer, I already had a midpipe from ebay (bolted on fine). Then I saw this DP/MP combo for $100, so I said why not. I am gonna sell the MP to my buddy for $65, hes got an HKS DP. I will post after the install and tell how it went. I hope I don’t need a new gasket. And I hope that the bolts come off ez, its only been 16k sense I have had them off.

Another prob. with these is that the faces of the mating flanges are usually cucumbered due to the welding heat and they are not reskimmed flat....Leaks galore.

BTW SNracing we've all been there or are there right now,you are not alone.

I like your story man it made me laugh....sorry.It's like "what now!" with every next step....I wanted to burn my car many a time.

I have that MP/DP and an HKS catback and it fits perfectly, the only problem I had was the flange on the dp I had to grind a little of the weld.

I just did a motor rebuild... so my engine isnt a v.irgin anymore.. :) hopefully next month when I do my DP..it wont be too bad either.... of course imma get a M2.. if they are still around... :(

snracing check your pm's

That sux, I got the "hks" dp off ebay for 120.00, bolted right up.

Why did'nt you use the original studs? Am I missing something?

your not suppose to use the original nuts.

the nuts are crushed at one end so they won't vibe off.

(also says in the FSM in big bold letters)

They usually take the stud out when you remove them.

You can get replacement studs/bolts at a auto shop.

most exhaust components are naughty.

Prolly didn't help to use the wrong bolts too :)

Even if the stud comes out (two of mine did) they screw right back in??

is that a question or a statement?

-sometimes they do

the ebay dp is definatly not ment to bolt up the stock cat, but i bet the mp would fit fine. i had to dremel out about a total of 2cm to get it to fit onto the cat. 2cm doesnt sound like a lot, but when your drilling out stainless steel with a tool that can barely handle ss, it sux!

actually im still there... i had some time to work on it again yesterday but still having problems. the bolts that the dp came with were too long for the threads in the manifold, which i thought was causing my leak. so i go to get shorter bolts to try and fix the problem. got the old ones out and new 1's in, put everything back together and started her up.... same F-N thing! i still have an exhaust leak at the manifold. a friend of mine is a mechanic for Mercedies (sp) so hes gonna take it up to his work where he has a lift, (much better than working under jackstands) and figure wtf is going on. hopefully my car will be back on the road by the end of the week.

pm's checked ;)

with the hks pipe, i think you are able to fit the dp over the studs since it has the small bend at the top of the pipe. with the pipes that do not have a bend in them, you have to take the studs out. and with my wonderful luck that i have, i stripped the original bolts.

ITS DONE! my friend took it to the dealership where he works, and fixed the exhaust leak. apparently the bolts that i got for it were to long as well. he put shorter 1's in, and it sealed right up.

man it sounds good! dp cleared up the exhaust path so the twins can sing. i cant really notice a diffrence in performance on the butt dyno, but its also about 90 degrees outside right now.

Wow...what a story. I too was considering buying a downpipe off ebay, because i figured a pipe was a pipe. Glad I read this before I bought it. I think now I'll come up with the extra cash and buy a brand from the rx7 store, or buy a used brand name off ebay.

Good to here that all is well now with your 7...

ok, so, i have to rub it in :) i paid my mechanic like $150 to put mine on... took them almost 7hours... took me like 30 minutes to drop off the car, pick it up again and pay :) it works perfect. the only thing i had to do was have the shop boys at work slot the cat-side holes .1" out from the center on each side so it would match right up.

This is a true statement. I used an expensive Bonez down pipe from good shop, before I went single turbo. It was a bitch and I never got one bolt holes to line up right. I eventually had to make one of the bolt holes bigger.
The mid pipe on my car is off e-bay and it looks and fits great.

Brady Mahoney

i got a M2 DP, there was NO fitment problems.
i didnt even have to take the studs out.

when i put on my Ebay set, the hardest part was getting to the bolts. I used the mid pipe it came with and saved the stock for emmissions.

i was thinking about doing that, but you have to have a tuneable ecu for a mid pipe. i dont have one, and having to retune the car and put the cat back on the car is just too much work.

So uhh, after reading this thread anyone in the Bay Area want to help with a downpipe install? :D I'm debating trying to DIY or just sending it to a shop where as said aboved I figured they'd charge about $150 to do it. They can afford to charge that since it averages out with some 15 minute installs and some 7 hour ones. The question is, 'Do ya feel lucky punk, do ya?'...normally when I ask myself that and say yes 7 hours later my head has a bump, my knuckles are bloody and my car is still broken :(

On the emissions stuff being that I'm in CA I have a storage spot in my garage where the stock air intake, pre-cat, etc will go to swap back in if needed for testing when it comes around again.

DP are alway a pain in the ass.

Just got my on a couple weeks ago. Also ebay bought. And did it go on easily, no!....But the idea is to do it yourself, make sure that it is done right. This includes buying new studs, nuts and gaskets and taking your time so you don't beat the car up in the process.

Take a deep breath every once in a while and don't worry about time. Just take each situation as a separate problem to solve.

I can't remember how many different socket and extension combinations I used in the job but it was a lot.

Also had a helluva time with the CAT nuts----I literally applied my foot (and tremendous force) to the wrench to get them off and my legs once squated around 500LBS...fortunately I didn't break the studs off.

Nevertheless, when I tried to mate the CAT to the DP it would not go because the heat shield over the CAT bumped up against the exhaust canal.

Don't know if anyone else has run into this problem??????
or if it's because my DP simply curves up too much but that was completely unexpected.
Have a Bonez hi-flow on the way which hopefully will connect right up to the DP. Didn't like the idea of attaching the CAT and all that weight to the DP without a bracket anyway so I'm hoping the weight reduction of the hi-flow will alleviate my concern.

TracyRX7---go ahead and give it a shot. Use lots of LW---that stuff really helps a lot. Be patient and allow for plenty of time. Keep the stock parts as you plan, make sure you raise the car safely. I use a ramp myself....just feel safer vs stands---there's less room but enough to do the job and easier on the car. Don't want my wife and kids cashing in on the policy just yet:).,
Work the nuts back and forth, don't be too aggressive---if you get them out a little and they tighten up, spray some LW and work it back in.
I thought the DP wouldn't be too much harder than the fuel filter and was completely mistaken.

Good luck!!!

TracyRX7...one other thing...I wouldn't just take it to any shop for this or anything at all. Rick's close to where you are, you may want to consider him.

Damn sounds like a nightmare you had there. But I have to say not all ebay parts were made alike. I am lucky my exhaust was already removed before I got the car because the bolts seem to stay in place. Well anyways read the threads and I used anti-seize to put my bolts on. Altother it took me about 15 min to install the downpipe. Holes lined up with precision, no alterations at all, so I am a happy man.

TSUDO DOWNPIPE ALL THE WAY!!!!!!

ps. what kind of bolts did you guys use, to install the part???

Downpipe install from hell #2:

So after reading this thread and doing some "recon" work (removed all of the intake hoses, checked out mainfold bolts, etc) I decided to send it in to a shop since they'll have exactly the right tools.

Three hours after they have the car up on the lift they call me, "The DP is on the mainfold now but it won't line up with the cat. Sorry it took so long but one of the bolts on the manifold was stripped. The next problem is the flange by the cat doesn't line up with the cat. We think by putting on some 8mm bolts instead of the 10mm we might be able to get it connected." ... "Sounds good to me go ahead."

An hour+ later..."We've pulled the entire cat off of the car and hooked it up to the DP and then we tried to remount but the cat wouldn't fit back onto the car, its too twisted. We've got the cat back on the car now and we're suggesting at this point that you pull the DP and get the flange removed and turned about 10 degrees so it hooks up."

So I'm picking up the DP to take it over to an exhaust shop to have the flange cut off and moved so it lines up :(

sounds like it pays to buy a slightly more expensive DP.. hopefully the HKS that I got will line up well, HKS are known for quality parts after all.

wow, that sucks! at least your not having to do all the work. what kind of dp is it?

Not certain, bought it used. I think it may be a Pettit (maybe this is why I don't see the downpipe listed for sale on Pettit's site anymore?).

From talking to my shop (they make their own downpipes) they've had whole batches come from their manufacturing like this (something probably gets lined up wrong on the machine that is doing the cutting/bending/welding and blam all of them wrong).

They had to return a whole batch of 50 and have the flange turned :( so this isn't the first time he's run into this problem.

As far as doing the work..I enjoy working on cars but you learn (either that or you can afford to have a choice) when its going to be enjoyable and when you're going to be cursing up a storm because you don't have a nice lift and all of the perfect tools to get the job done. Picture how long this could have taken me sliding around on my back under a car on jack stands without a second person to hold the cat/etc trying to line the stuff up.

Final result of my install: https://www.rx7club.com/showthread.p...hreadid=307954

Uhhh.. I just went to Pettit's site. Part EX-PE-GB198, 3" DP that replaces pre-cat. $299. That's where I got mine ages ago. Zero problems.

An aid is to replace the long stock precat studs that are in the turbo housing with shorter ones, N391-13-456 from mother mazda. Get 4. The DP will slide right over them. The short side radius of the DP makes the last stud difficult to thread the nut over, but you just move the dp out from the turbo, get the nut started, then move it on. Use split lock washers under the nuts to deal with oversized welds.

PB blaster rust remover is YOUR friend, as is running the car before the initial spray of PB blaster (allows it to get into the threads). I had my precat off the car before it was cold (but not before it stopped beating :) )

Just my $0.02. Pay a little more for the DP, avoid this mess!

Yeah I did more digging on the Pettit site later and found it listed (but too late to edit the post). As in my post above pointin to the Classifieds section thread it turned out to be the downpipe from the RX7Store downpipe/midpipe combo (so the DP may have never been fitted to the main-cat just as a combo to the cat-back).

You guys should always research on the part you are buying for fitment and quality. I got an old style PFS DP for cheap and it fit just fine without taking stud out. M2, Pettit and HKS are others that are good quality. I would not buy anything else. Saving $100 and spending 5 hrs dremeling the holes is not worth it.

I recently bought a used RB dual catback as well. It was a 45min job to install. I highly recommend you get a catback after the DP bc you'll be equally impressed. RB and M2 are quiet while others can be loud.

What you guys think about this combo dp and mp from rx7 store?
http://www.rx7store.net/index.asp?Pa...ROD&ProdID=596

The combo together fits just fine (from what I've been told by others). The DP by itself won't hook up to the stock main-cat (at least the one I have doesn't on my car as said above).

NOTE: RX7Store does not sell the DP by itself, just the MP (which may or may not be the same MP as with the combo) so it probably was never intended to be a bolt in replacement for the pre-cat.