GirlyGirl7

Hi, I have a 93 and the car has the air intake system and (chome pipe thingys with filters at the end?) It also has the Apexi GT exhaust. I saw somewhere that the Downpipe from HKS is only $220 and it will make my car faster. How much faster will this make my car and what do I need for it?

rx7eaven

It will give you 10-15 hp I believe. But more importantly it will relieve some stress on the turbos caused by the back pressure from the pre-cat.

theman

It will make your car exactly .5 seconds faster!
Just kidding, there are too many veriables to know but you'll definitely feel a difference.
It's also good for keep underhood temperatures lower since the precat holds alot of heat up in the engine compartment...

Pressurized

The downpipe is a performance mod as well as a reliability mod.You'll get anywhere fom 10-20hp at the wheels and also get rid of heat in the engine bay.

HOWEVER, since you already have an intake(shiny pipes with filters) and the Apexi' GT, adding the downpipe will probably be too much for the stock ECU to handle. You should remap your computer first.

Computer remaps are anywhere from $500 used, to $700 for most brand name ECU's.

417RX7

the Downpipe is more a reliabilty mod than a hp mod. I highly recomend doing this as one of the first steps, like what has already been stated it puts less stress on the turbos and help keep engine temps down. I would go with the HKS becuase it installs easier than most others. look them up at www.rx7store.net the link above^

417RX7

Pressurized brings up a very good point, don't forget about fuel mods. they are very important and should be considered before you go very much further. Also look into getting a boost guage if you don't have one already.

BrianK

I just installed my M2 downpipe (or rather, had it installed - it's a huge PITA). The installer said that it was just as easy as the HKS - it fit perfectly... unlike many of the other mandrel bent downpipes.

I noticed a huge decrease in under hood temps. As a comparison, I could drive just a few miles, hop out, put my hand on the passenger's side of the hood and it would be almost too hot to touch.... with the DP installed, I drove for an hour, got out, and the hood was barely even warm.

I noticed more difference in power in the higher rpm range - kinda hard to tell how much because the car is so fast to begin with.

Flybye

If you don't currently have the $$$ to buy an aftermarket ECU, but are itching to get the DP, you can basically install these little things called restrictor pills. You see with the DP installed, you may possibly boost past fuel cut. These restrictor pills will allow more pressure to reach the wastegate and not allow you to overboost. That way you can safely run a DP. If you don't have restrictor pills currently installed, then you may need to slightly drill out the nozzles where the hoses are attached for the wastegate.

Either way, you dont have to run an aftermarket ecu with just simple boltons like intake, CB, and the DP. The only thing you DO need to worry about, though is overboosting. Every FD is different which is why it is an issue for some and not for others. It was an issue for me, but instead of controlling boost, I just jumped the gun and got the PFC :p

Besides, I'm sure Greg will be willing to help you stick all the parts in

Dan

Chicks with bad-*** cars RULE

95R2-89TII Ground Zero

The second turbo in your car is getting baked. The pre-cat holds the heat into the turbo area and after a while, it just bakes it. The downpipe is one of the first upgrades that everyone does to the FD, because of those characterisitics.

rx7eaven

Agreed but what did that have to do with anything?

I got the m2 as well and love it. Everything fits fine.

maxpesce

M2's DP is uses larger pipe than HKS (3" vs 2.75") also HKS makes both Stainless and Mild Steel versions ot their DP - Mild Steel is almost worthless for a DP it will burn thru in a year or two. The $220 price is probably for the MS pipe

To reduce under hood temps even more have the pipe Ceramic Coated and/or ThermoTec wrapped.

Tommy

I didnt personally install my pettit dp but the guy who did said it gave him no problems. Adding the dp will also allow your turbos to spool much quicker.

maxpesce

Check my Mods in my sig - I run the stock ecu and have no problems - I only ever hit boost cut on very cold days @ WOT In third/fourth - w/ a stock ecu you can't actually Overboost because at 12.5 psi the ecu cuts fuel flow to the rear rotor! that is why its there, to prevent Overbosting. Also at WOT and 12psi bost my AF Meter shows 2-3 bars rich, so I am still getting enough fuel.

rx7eaven

Where can you get the thermo wrap stuff? How much? Do you have to take the dp off to put it on?

Thanks

Dan

also how long will it take a "MECHANIC" to install? Mine charges 70/hr I just want 2 plan?

maxpesce

ThermoTec should be available from Summit Racing or Racer Wholesale etc. Mariah wrapped my DP prior to installation, but If you are paitent and have small hands you could do it on the car. The stuff is a Kevlar fabric non-adheasive tape that is about 2.5" wide that wraps around and around and around and around and around and around about 50 turns for a DP. and is held tight w/ hose clamps.

BrianK

I spoke with two shops before getting mine done. both quoted me between 3 and 4 hours labor. Mine ended up being a pain (gladf I didn't do it) and took 5.5 hours. I know they weren't trying to rip me off because 1) I was there - in the garage - the whole time and 2) they only charged me for 4 hours because that's what they quoted me before they started.



BTW: I got mine jet-hot coated. pretty nice. not too expensive, but did take a while. They orignally said it would be one week but it took them three weeks.

if you get yours coated watch out 'cause it'll smoke when you run it for the first time (while the coating cooks itself on), and it smells like ***** while it's smoking.

RyanREX

How legal is a downpipe? Are they street legal? Would you recomend HKS?

Pressurized

I would recommend the HKS only if you're tight on $$$ and you're doing it yourself. The HKS is slightly easier than some of the others to install because it retains the stock studs. However, if you're gonna have a mechanic do it, there's nothing better than a stainless steel downpipe.

But be wary, as a lot of people have mentioned, this mod is not for the faint of heart. It can and probably will be a huge pain in the ***. I couldn't do mine, I installed everything else, but the downpipe was impossible. I needed to cut it off with a torch and unfortunately I don't have one. So I ended up paying $264 for just the install.

Cheers!

m0t03

How much power soes a midpipe give you

RyanREX

Thanks!

417RX7

I installed my HKS in about 2.5 hours, with me and a friend. It wasn't that hard provided you have a large breaker bar to break the nuts loose. I don't remember the exact lenght of one I used to do it but it was long. Longer the better provided that it doesn't get in the way of turnning the bar. Also I have small hands this might be why it went quicker for me. Another thing to consider and the reason I went with the HKS(cheaper one) is because I am planning on going single turbo down the road a little ways and the DP would then be worthless to me.