I am getting ready to do the vac. hose replacement and am doing all the reliability modes/upgrades while in the process including the Efini Y pipe. The only thing I have not purchased yet is a downpipe and I have a couple of questions before I decide whether to do it or not.

1. Other than the forth coming Efini mod., the engine is stock, no power mods. I will be putting in a OEM style K&N filter. Will a downpipe give me boost spikes or require any additional crap to prevent damage from over boost?

2. Is there a #1 choice in DP manufacturer/brand for a stock engine? Looking for plug and play. I am looking at a Pettit DP because they are just down the road from me. Any know issues with a Pettit?

3. Do the DP's come with the needed gaskets/hardware? I don't see "kit" or any mention of "everything needed" on most of the sites selling DP's.

I have "searched", read the FAQ. Have a headache now. I don't need to know how to install it...got that part. I just don't want to stick something on that requires me upgrading the ECU or other parts. Figure since I am doing the Efini Y, it would make sense to plug in a DP if it is safe.

As usual, thanks...

 

I personally like the Pettit unit myself. Mine came with the required gasket to the turbos but NOT to the catalyst.

Make sure and replace the O2 sensor while you are at it....no better time.

 

as long as you still have a cat in there you will be fine installing a dp, my pipe came with the gsk to the engine but not to the cat, the engine 1 can be reused if your pipe doesn,t have it.

 

Replace the hardware and gasket while you are at it.

 

I recommend SMB! I got their 4" tapered to 3.5" DP in my car. I was finally happy after trying 4 others (oem jdm without precat, ssautochrome, bonez and hks)

 

Bajaman, yes an O2 sensor is in the $2K pile of goodies that are going into the 7 this week.

Ihor, Украинский язык или русский язык? Would SS cap head Allen's be a better way to go than straight bolts? This is presuming the studs are not necessary.

 

will the car need a remap if u just put on a down pipe?

 

I am running an Efini y-pipe, K&N intake on stock airbox, downpipe, and most recently a Racing Beat dual tip cat-back exhaust.

My boost stayed exactly stock with the y-pipe, filter, and downpipe. It went up a little bit with the cat-back. I saw only elevated boost (no spikes or creep) by about 1psi.

I have a Pettit pipe and it fits pretty well. HKS are an easier installation since the upper end is smooshed to fit past a RHD steering shaft. Bonez also makes a reputably good quality part.

Probably not. Both dp's that I bought from RX7Store did not. Unfortunately you may pay a premium if you rely on your downpipe vendor to also sell the OEM gasket and hardware. That stuff is still very expensive from Malloy or Mazdacomp. Since your car is only 19k old, your hardware may be re-usable without issue. If you end up with a stud that backs out with the nut still attached, you can re-use it but I'd add a thin washer to make sure the stud doesn't bottom out before the nut is pressing on the flange.

Some folks will tell you to get studs and nuts from ATP turbo instead of the inconel (or is it monel?) stock hardware. Whichever you use, make sure you get some high-temp anti-seize so that the next time is easier.

You can also get a much cheaper crushable nonmetallic gasket from pineappleracing.com. Rob at Pineapple says it might blow out in high backpressure applications (i.e. nearly stock exhaust) but I've been running one for a year now without a leak.

Just go for it.

 

Consider some type of heat barrier on your DP before installation. A ceramic heat coating or simply some inexpensive DEI header wrap with their hi-temp coating/seal over the wrap.
Either way, it will make a significant difference on underhood temps. Seemed to quiet mine down just a bit too. And cooler will be kinder on all those nice new bits.
As for safety....it would be much more dangerous to leave the stock pre-cat in there.

 

BTW you can find used downpipes on the classfieds. If you look a little bit you'll find name brand ones with the coating or wrap already on them for a very good price. I know you're not frugal but it can be quite a bit faster.

I've done the DEI header wrap and I won't do it again. It works fine but I don't enjoy working with fiberglass, especially when it's above your face as you work. Mine is unwrapped/uncoated right now and if I felt compelled to insulate it again I'd do the jethot or other ceramic coating.

Dave

 

I would have liked to go with Jet-hot too last year. Just ran out of time. I agree it would have been preferrable, especially if looks is a big concern. But either performs well and the OP could wrap it while it's out of the car. And the DEI paint/sealant works well at keeping any dust from coming off.

 

It's not the wrapping that's unpleasant but working around a wrapped part that's not fun. And every other time you're in that area for stuff. You either get it dug into your forearms or you rub against it and it falls onto your neck and face. At least with safety glasses I haven't gotten any in my eyes yet.

FYI I was looking for other stuff but saw a couple of coated name-brand downpipes for sale in the classifieds. There was a coated Pettit for $140.

Dave

 

Thanks Dave...dumb me had not thought of the, Se Vende section. Headed there.............now.

 

Baby powder is your friend it will clog you pores and prevent fiberglass from entering.

 

I concur on the Jet-Hot coating. Fiberglass header wrap is for the birds - don't waste your time with that crap.

I have had 2 downpipes Jet-Hot coated, makes a VERY big difference, and the stuff is absolutely bulletproof. It won't even come off with a wire wheel on a bench grinder!

Find a good name brand downpipe - might want to go with Pettit if you're near them. They might also be able to do the ceramic coating for you, I know they do a lot of stuff with ceramics. Put it on with new hardware and gaskets, and enjoy.

Dale

 

I would keep an eye on your boost gauge after any modification to the intake or exhaust.

I had to install a Hallman MBC to control the boost level with just a drop-in filter, downpipe, and intake port smoothing/matching. Ports were not enlarged, exhaust ports were not touched.