nmo93

how hard is it to install a downpipe by yourself? i would imagine the hard part would be to try and not break the bolts?
my other question is in hp and torque which is the best way to go: an intake and catback or a dp and catback? i read on robinette's site that the dowpipe should be the first mod. do all of you agree? any help would be aprreciated, nick

Mahjik

iTrader: (1)

Downpipe and catback..

You want to remove the pre-cat first so it will help reduce the under-hood temps.

RyanREX

The install will take a couple of hours. All you need is hand tools and patience. The hard part is the bolts and getting the new one on w/o the gaskets falling off. We used tape to hold the gasket on and it melts away.

Turbo_F1

Couple hours and try not to strip any bolts. I had the bonez dp and the bolts the gave us were really shitty so we used the stock one.

Turbo_F1

Here is a question the part where the downpipe connects to the cat. The bolt that connect to the frame on the dp, is it ok not to have it bolted. I was not able to fit the bolt in. Wondering if it could cause problems?

c00lduke

what i did that i just tried was take off all the pipes on top of the turbo so you can get easy access to the top 2 bolts.

BrianK

dp should be first.

dp install can be very difficult - it depends on a lot of things. I had a rotary shop do mine for me, it took them 6 hours. You have to take off everything between the abs controller, UIM, and intake - down to the turbo. There's a lot of stuff there, so you'll need to be comfortable getting way down in there. I was also told that the nuts that hold the pre-cat to the turbo are, for lack of a better term, destructive - in order to ensure that they don't back themselves out, they warp themselves into place - taking them out and re-using them is not the best idea. Just to be safe, I went down to the dealer and got some new ones. They are $4 a piece (kinda expensive for nuts, but, oh well).

Personally, I would go dp, cat-back, and a K&N drop in if you're worried about the price of doing all three at once.

edit: just FYI: I don't know how long you've had your FD, but I noticed a slight drop in the very low end torque when I added a DP (which makes sense when you think about it), after having been used to the stock powerband for a while. There is, however, a noticeable improvement in the upper rev range, and the turbo sound is pretty cool.

djantlive

Did my own DP install 2 wks ago. Took me 6.5 hrs over 2 days. Definitely buy a DP that does not require stud removal - M2 SS and HKS MS ones are popular and sold on the rx7store.com here.

You don't have to remove the ABS, UIM. Just the intake hoses. The stock precat heat shield was a pain to slide around to expose the bolts. I ended up removing the precat headshield with the precat like move people did.

You will need a lot of patience, a lot of time to soak the bolts with WD40 - hence the 6.5 hrs over 2 days. Those folks telling you that it take a couple of hours are either optimists or were having so much fun that they forgot that it was 11pm when the finished the job.

Section8

iTrader: (6)

Is there one DP that is better than others, or one that I should avoid entirely? Judging from these posts it looks like the M2 or a DP that doesn't require stud removal would be a better option for someone like me that's going to do as much work as possible themselves.

djantlive

I think the M2 is best. The RX7store.com has good pictures of M2 and HKS. The HKS has a somewhat restrictive bend compared to M2 at the front so you might as well pay $100 more for SS and a little better flow.

I have a used PFS one that similar to HKS and I can't complain anything about it. So, you can't go wrong with either one (M2 or HKS).

RyanREX

The worst part is the heat. The bolts will be really HOT if you don't cool down the car before hand. Take the hoses off the intake and it should be easier.

TobiasRX

Do u need to upgrade the ecu to put on a ecu and remove the cat-back?

TobiasRX

sorry, ....to put on a dp

twinturborx7pete

iTrader: (3)

i just bought my downpipe and it should be here monday... came with new bolts and gaskets. SS... i'm just hoping the install doesn't take me forever and a day.. i'm not the most patient person when it comes to adding HP!

cyanide

does anyone run open downpipe? with an upgraded ECU of course to help control the extra fuel for boost spikes.

BrianK

cyanide: all downpipes are open... don't know what you mean by your question. (unless you mean nothing attached behind the DP - in which case you'll want some serious ear plugs)

TobiasRX: dp & cat-back shouldn't require an upgraded ECU unless it bumps your boost up to at or above 12lbs. (get a boost gauge). You'll need an ECU upgrade if you hitting above 12.

as far as which dp is best - they are all pretty much the same. The number one concern should be ease of installation. The M2 fits in perfectly, as does the HKS. I don't have experience with any others, but I know that there are a couple out there that fit like crap and make the installation that much more difficult.
I've heard that the SS dps are louder becasue they are thinner. I don't know if that's true or not, tho.

gotorx7

Mine feels exactly the same! And here is the Dyno sheet of before and after (if you're interested)..

Dyno Sheet

legendr35

dp install is ez if you have the correct tools. make sure you spray some liquid wrench on the 4 studs, this is essential, I didn't use it at first and the bolts broke in half. takes about 3-4 hours, sometimes less.

TobiasRX

Im gonna get a boost gauge and build my own dp.
wich size on the dp are best? 2.5" or higher?

maxpesce

The DP needs to be AT LEAST 2.75" ID - M2 is almost a full 3" and HKS is right at 2.75" the same as the stock precat piping.
as far as making your own the tricky part will be the top bend - it has to be very tight because there is very limited clearance between the turbos & the chassis.

Also consider wrapping the DP w/THERMOTEC Wrap or a similar insulation wrap - it will greatly reduce radiated HEAT and also muffle the sound slightly.

nmo93

does anyone own the rx-7 store downpipe? or have you heard anything about it? i know most dp's are the same but i am just curious as to how easily it can be put on. nick

WANKEL POWER

Are there any special issues that come up when installing a downpipe with an automatic transmission?

2 hott

iTrader: (4)

Just installed my RX-7 Store DP and MP pipe today took all day due to takeing the intake part of the turbos off to get at the bolts eiaser. Everything bolt together great. They are great I highly recomend them. Can't beat the price either. It is nice to have someone assist you in putting the DP on for some reason only one stud stayed in the turbo the other 3 came out with the nut. But I got it all together w/ striping or breaking a stud. I had soaked the studs in penetrating oil yesterday to help in the removal. Thanks again Jason for the good service!