Doc Holaday

iTrader: (1)

I purchased a 87 TII almost a year ago and just had it in storage, it was written off, but has minimal damage. Had a nasty exhaust leak, that I found to be the DP not even bolted to the turbo. The test pipe is rust out, but the rest of the system seems to have been upgraded at some point in the car's life (only 155km).

Im not a complete noob to the FC world, have had my 87 n/a since high school, but the turbo world in a newer thing.

I would like to put in a different downpipe, whether it comes with a new test pipe or not isn't an issue. The problem I'm seeing is to go to a 3" DP, or stay with a RB or Corksport 2.5" piece?

I do not have a HP goal, as I plan to drive it for the summer and sell it. This will be one of the few power upgrades I plan on doing.

http://www.racingbeat.com/RX7-1986-1...rs/S16207.html

http://www.corksport.com/corksport-p...ck-flange.html

or

http://www.ebay.ca/itm/1986-1992-Maz...ht_3395wt_1398

Thanks,

Jon

RotaryRocket88

iTrader: (7)

With a stock turbo, 2.5" is fine, but you can go up to 3" too. The RB downpipe is intended for use with their presilencer, so it will come up 3" short of the normal position of a stock main cat. If you are using a pipe that replaces the main cat, you'll run into this same issue unless you use RB's silencer.

The corksport 3" pipe will require a 3" test pipe/resonator/presilencer & 3" cat back OR some sort of adapter to down size. There is no guarantee that a 3" pipe will bolt up properly to a 2.5" pipe, and even then it will almost definitely leak. I dealt with exhaust leak problems on my NA using a 2.5" to 2.25" connection.

The no-name, ebay (Chinese) down pipe is a big gamble. It may be thin-wall tubing with crappy welds, or it might actually be a decent part.

Doc Holaday

iTrader: (1)

Im just concerned about possible boost creep by going to the 3" DP, or is that not an issue being fairly stock?

With any of the DP's, I would install and take to my 'shop' to have them weld in piping to join it up. Whether its a 3"- stock id" reducer or just something to join up. It will be welded and sealed

With doing a DP will a fcd be in my near future? Im planning to just add a cai ( properly shielded and plumbed) and thats it for now. I was hitting fuel cut with the stock dp in place but not bolted driving it home, don't really want to risk it over $100.

RotaryRocket88

iTrader: (7)

If you were hitting fuel cut (due to creep) with a stock down pipe, going larger will enhance the effect. Adding a free-flowing intake will also add to it. The only fix is to remove the turbo and port the wastegate. If you go that route, I'd suggest switching to an S5 turbo & manifold. They're fully divided, and the wastegate has 2 ports that can be enlarged to eliminate boost creep. I have none on my car with an S5 hybrid, 3" intake & open 2.5" exhaust.

Don't waste money on an FCD. If adding only that w/out porting the wastegate, you'll overboost and blow the engine. Fuel cut is harsh, but it's better than the alternative. Racingbeat suggests an FCD as some sort of requirement when upgrading the exhaust, but the reality is that's a recipe for disaster w/out taking other steps first.

And in the end, FCDs are horrible and antiquated. You can have Pocketlogger chip your ECU to remove the fuel cut code, and make other positive changes. The 1.x chips are cheap and simple.

http://www.pocketlogger.com/index.ph...age=1&ecu=S4T2

The problem with FCDs is they fool the ECU into thinking boost pressure is lower. This has 2 nasty side-effects: 1) less fuel will be delivered 2) less timing will be pulled. Without a means of correcting fuel and timing, they're just plain dangerous.

Doc Holaday

iTrader: (1)

It wasn't creeping w the stock exhaust working correctly. The Dp wasn't even bolted to the turbo, just in place. I'll just order the corksport dp kit, has a new gasket w it, rb wants 50$ for theirs. I'll see how the boost sits with a properly operating and sealed system. That chip looks like a decent alternative. Must come with good instructions for diy installation? I would only want to go with the 1.5 though, no plans to up the injectors.

dwb87

iTrader: (22)

If you have even a little bit of soldering experience, you can do it. It's only $20 more to have Digital Tuning do it, but doing it yourself will save a bit of time... As long as you're confident in your soldering abilities. ;-)

Have you considered porting the wastegate on the turbo? This is a great 'How to' with information on boost creep and overboost...

Aaron Cake: Extreme S4 Wastegate Porting

You can consider swapping the superior S5 turbo and manifold.

FC3S Pro: S5 Wastegate Porting

Doc Holaday

iTrader: (1)

I don't have any issues doing a little bit of some soldering, got some experience being an Power Electrician!
Porting the wastegate doesn't seem to be that tough, but wasn't planning on pulling off the turbo etc. to get to it. Will definatly keep it in mind though.

Thanks for all the tips here guys, exactly what I was hoping for.

schaft

iTrader: (1)

http://topspeedauto.com/productcart/...idCategory=267

If u decide to change it all out

con-3-fc3s

Corksport is what ive been using for many many moons!..lol Good fit&finish..

Doc Holaday

iTrader: (1)

So its pretty safe to say any "name brand" down pipe is going to be fine to purchase. Just stay away from the ebay ones as they may have thin wall piping used?

dwb87

iTrader: (22)

^ Pretty much.

I've always been amazed with the quality, performance and sound of the Racing Beat REV TII exhaust. As for CorkSport, I have no experience with any of their exhaust systems.

Doc Holaday

iTrader: (1)

Ordered the Corksport dp on the weekend. Once I get it on and take the car for a drive I'll see what else it will require to run nice and smooth. I will probably end up gettting the Rteck7 1.5 chip and a cone intake filter and adaptor though.

rx-7PRIDE

ppl always say avoid e-bay but its not e-bay u must avoid its just the no name brands or e-bay brands you must avoid, high end companies also have very good and reliable parts on e-bay

Doc Holaday

iTrader: (1)

Got the Dp installed tonight, but the car is still in pieces as I'm going through everything and replacing as needed. Had to order the turbo to DP gasket after opening the Corksport package and there not being in there. I assumed that hardware and gasket would be that gasket, but it was the one between the dp and rest of the system.

Another quick question. I'm expecting 1-2 psi increase with the dp, and the rest of the exhaust. I do have a 2.5" straight piped system (straight through 3" muffler) on my N/a that runs great. How much psi increase would this system typically produce on a s4? I'm thinking it would be nice to quiet down my na with the dual stock system on the t2, but don't want to cause to much of a psi increase on the t2.

I guess until I drive the t2 with the current exhaust set up its hard to know what it will do. How much psi increase can I run without boost creep issues?

Thanks!

Doc Holaday

iTrader: (1)

Good To see another member from the SK!

misterstyx69

iTrader: (142)

If you go RTEK then spend the little extra and get them to install it.That way if you have problems it is their problem.
I am pretty good at soldering but I went bananas just trying to do a Self install of the Chip that they supply!..it is a lot of pins and you gotta get them all hot at once or the old chip doesn't come out.
Trust me,Save the hassle,have them do it!