Helix Power has just released their high-flow metal substrate catalytic converter downpipe for the Subaru Impreza WRX/STI. We air-freighted in 10pcs for those that are interested. Supply is VERY limited. If this is what you are looking for, please order yours today

This particular downpipe incorporates Helix Power’s first-rate bell-mouth downpipe, with the addition of a 200 cell Metal-Substrate high-flow catalytic converter and thermal barrier heat-shield. The 200 cell Metal-Substrate downpipe has been tested by us to yield 7-10whp over the factory twin cats, while able to pass stringent California smog standards. The thermal barrier heat-shield assists in rapid warm-up of the cat for maximum efficiency and helping to reduce engine bay temperatures.

Introductory Price:
$399 Shipped!!!



Please contact us with any questions. Thanks!

Gary
www.gruppe-s.com
gary@gruppe-s.com
510-498-8400
510-498-8882 fax

 

How much picked up paid in cash?

 

I noticed the test day was 11/11/2003, that mean you guys already had it back then or what?

 

Guess they've done a good bit of testing with it then

 

Hi,

We can offer $399 picked up. ( Including the new 8.75% California sales tax )

Yes, we have had the prototype high-flow cat for awhile and done some extensive tests on it (I think I have over 10K miles on mine). Only recently did Helix have the manufacturing capacity to finally start producing these.

Thanks,

Gary
Gruppe-S

 

holy sh*t that new tax is insane. anyway. i had a turbo back on my wrx and i'm thinking about picking this dp with cat and a hks hiper exhaust.. do you think this setup is going to be loud as all hell again? or does that catted dp help with the sound at all?

thanks,

Andrew

 

dddddddamn 8.75
so not cool

 

so this will pass CA smog? or will i still have to swap for stock when getting it smoged?

 

while able to pass stringent California smog standards! (read it again homie)

 

Are we looking at the same power gains between the Helix downpipe with no cat and this new one with a cat???..or does the no cat yield more whp??

 

How do you compare the catted dp with the ones without?

 

DRU18 - The high flow cat does quiet the system down a little bit, I did notice a difference when I installed it on my 04 WRX.

Dorifto88 - Yeah

Blue Burr - Yes, our 04 WRX as tested was able to pass california smog.

Hyper29 & White Wagon - Unfortunately nothing flows better than a straight pipe. There is a approximately a 5-7whp difference between the high flow & the straight pipe. However the high flow cat offers a huge improvement over the factory cats (200 cell metal substrate versus 400 cell ceramic as well as larger diameter flow).

Thanks!

Gary
Gruppe-S

 

So helix decided against a metal substrate cat? I guess it's smarter to keep the cost down. Is there a real difference between metal substrate and ceramic because I know the metal substrates are substantially more expensive.

 

Hi,

Actually the Helix Cat is a metal substrate 200 cell. I *believe* the factory cat is 400 cell ceramic.

Based on the flow test data, I think it would be extremely difficult to run this clean at these flow rates with a ceramic cat.

To clarify, the Helix Cat is a METAL SUBSTRATE (yes all those nice rare-earth elements!!) 200 cell cat.

Cheers,

Gary
Gruppe-S

BTW, we're currently sold out on the catted downpipes. Next shipment is 2-3 weeks (good idea to reserve yours today!)

 

You're ripping people off in CA!!! The sales tax here is only 7.75% still...