Test Pipe: What difference does it really make?

[desertmike680]

So that and what makes the speed 3's exhaust sound so good as compared to the speed6's. Whats the difference there too?

 

[markspd6]

diff is huge for the money.. and easy to install.. (poke) too many details to explain all exhaust diffs.

 

[USAFVMI08]

I'm assuming it has something to do with the setup of the exhaust system itself... ie one tailpipe on the MS3 vs 2 tailpipes on the MS6. My buddy has an MS3 with a Corksport Power Series turboback and compared to the same system that I have on my car, I can say that his is obnoxiously louder than mine. Still sounds nice but I feel that mine sounds better and is WAY more bareable than his.

 

[FORZDA 1]

So that and what makes the speed 3's exhaust sound so good as compared to the speed6's. Whats the difference there too?

The second cat has a restrition in the inlet (~2") to the keep enough backpressure on the turbo exhaust to help with oil getting past the turbo turbine side and smoking. The test pipe eliminates the restriction and thusly the car revs a bit higher before falling on it's face.

The sound difference in the 3/6 exhaust note is tuned by Mazda and is most certainly related to the intended use of the car, a hot econo hatch vs a mature sports sedan...

 

[desertmike680]

Thanks Forzda. By eliminating the 2nd cat with a test pipe doesnt necessarily mean that the turbo will smoke does it? Also, is there a noticable tone difference with a test pipe too? I would also assume that when it comes time for an emissions/smog check, that the 2nd cat would have to be put back on in order for it to pass.

 

[FORZDA 1]

Thanks Forzda. By eliminating the 2nd cat with a test pipe doesnt necessarily mean that the turbo will smoke does it? Also, is there a noticable tone difference with a test pipe too? I would also assume that when it comes time for an emissions/smog check, that the 2nd cat would have to be put back on in order for it to pass.

If you really pay attention you will hear a slight increase in sound with the TP and it may or may not smoke with the TP. The emissions check depends on how your area inspects. It won't pass a visual if they're smart, but it should pass a sniff or ECU code check just fine.

 

[tunersteve]

With a 2.5" TP on my MS6, the sound is very very minimal. I do notice a better spool up about 2-300 revs sooner than without the TP installed, and improved response between gear changes when getting on throttle.

 

[USAFVMI08]

Thanks Forzda. By eliminating the 2nd cat with a test pipe doesnt necessarily mean that the turbo will smoke does it? Also, is there a noticable tone difference with a test pipe too? I would also assume that when it comes time for an emissions/smog check, that the 2nd cat would have to be put back on in order for it to pass.

I don't have an cats on my system and I've had zero smoking.

 

[coyfish]

Exhaust doesn't cause smoking. It only reveals a problem that is already there.

 

[USAFVMI08]

Exactly. Which means my unreplaced turbo was a-okay from the factory

 

[StormTrooper6]

Exhaust doesn't cause smoking. It only reveals a problem that is already there.

this is my only worry and the only thing that has stopped me from a downpipe so far

 

[SamNavy]

On the MS6, the stock 2nd cat has a heat shield over it that is removable. You can take it off and stick it over the SU Test Pipe. It gives a completely stock look. You'd have to get right up to it and look through the fins on the shield to see that there wasn't anything inside. Bonus for those worried about visual inspection.

There is a noticeable improvement in spool/power/smooth... the butt dyno says 5-8whp... noticeable but not like it's gonna blow your mind. Plus after a few days, you'll get used to the new power and be looking for something else. It's well worth the money. There are always TP's for sale used in the classifieds... it's a good first or second mod.

 

[USAFVMI08]

The race pipe from Corksport is also enlarged so it looks like a cat as well.

 

[FORZDA 1]

........

Hey Sam! When you coming back?

 

[nickows]

Please excuse the newb question, but is a test pipe and a race pipe the same thing?

 

[Nosaj]

Please excuse the newb question, but is a test pipe and a race pipe the same thing?

yes

 

[shadesofgray19]

I've been thinking about a test pipe as well but am unsure. Not sure if I want the corksport or one of the others that pop up in the FS area. SU charging the same price as Corksport's resonated pipe for the 3" pipe is rediculous. I've been thinking is it really worth it and can I run a stage2 OTS map with just the test pipe?

 

[SamNavy]

Hey Sam! When you coming back?

Up for orders in December... almost zero chance it will be back to Norfolk. We've still got the house there and I'll have to come back and check on the renters at some point for along weekend, but I don't think orders are in the card for another 4-6 years if ever. Sold the Miata but should have a nice Stage1+ MS6 when I get back... nothing to hold a candle to yours, but it's the wife's after all. Tell the crew I said HI!

Please excuse the newb question, but is a test pipe and a race pipe the same thing?

Yes. It's just a hollow pipe that is a a direct replacement for a cat. Remove cat, install TP/RP in it's place using stock flanges and stock bolts(usually). Turbocharged vehicles benefit extremely well by removing even minor amounts of exhaust backpressure... way more benefit than on a naturally aspirated vehicle.