Time to buy a downpipe!

[whostorm05]

It's March and almost nice weather time again, so almost time to take the Supra out of storage.

Anyone running the Twisted Tuning Stage 1 or Stage 2 downpipe? Looking for reviews. I'm leaning towards Stage 1 as I doubt I will ever install a 4" exhaust system on the car. I'm sure there's very little difference in all of the different downpipe options, but figured I'd ask just in case anyone has any personal experience with them.

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[Twisted Tuning]

There are a couple people on here that have either my stage 1 or stage 2 downpipe. I have a couple reveiws via text and email. But hopefully the owners can chime in.

One thing i can say about downpipe is that there is no instant choke down of flow right off the turbine housing like most of the other options. Ours starts off as 4.5" at the turbo and gradually necks down to 4" then down to the stock exhaust size.

Iirc most others instantly drop down to the stock size right off the turbo.

 

[whostorm05]

I'm trying to decide between the stage 1 and stage 2. No current plans to replace the exhaust but ya never know.

 

[Meraki Autoworks]

How about the Active Autowerke downpipes? We have customers running their catted version with no CELs.

Let us know if you would like pricing on that, you have our #!

-Josh

 

[Extreme Power House]

It's March and almost nice weather time again, so almost time to take the Supra out of storage.

Anyone running the Twisted Tuning Stage 1 or Stage 2 downpipe? Looking for reviews. I'm leaning towards Stage 1 as I doubt I will ever install a 4" exhaust system on the car. I'm sure there's very little difference in all of the different downpipe options, but figured I'd ask just in case anyone has any personal experience with them.

If you are looking for a downpipe that does not throw CEL, Active autowerks chatted is the way to go.

In terms of power, sound, and fitment, all proven brand will perform the same

We offer Acitve Autowerke, VRSF, CTS,etc...

 

[iND-Distribution]

We are currently running a prototype AMS Performance catted downpipe on the iND Supra. Previously we ran the catless downpipe and performance feels identical. No odor or CEL with the catted set.

 

[satindragon]

Very nice. Can't go wrong with AMS or Active Autowerke.

 

[whostorm05]

We are currently running a prototype AMS Performance catted downpipe on the iND Supra. Previously we ran the catless downpipe and performance feels identical. No odor or CEL with the catted set.

Would love to see a dyno test of the difference between the catted vs catless downpipe.

 

[satindragon]

Would be nice to see. I spoke to AA before purchasing mine and they said that until you get past 600 whp (i.e. upgraded turbo), there's not much performance difference between the catted and catless.

Remember with the catted downpipe, you're using a higher flow cat along with eliminating the downstream cat in factory downpipe. That's removing quite a bit of restriction. Today my car made 372/466 on a mustang dyno with an AA catted downpipe if that helps with making your decision.

 

[whostorm05]

We are currently running a prototype AMS Performance catted downpipe on the iND Supra. Previously we ran the catless downpipe and performance feels identical. No odor or CEL with the catted set.

Any idea how many cells for the cat? Looks like it's 4" in diameter at the flex section correct?

I'm still researching but so far the only other one like that catted I have seen is the ETS Downpipe

There might be others but I haven't found one yet.

 

[Extreme Power House]

Would be nice to see. I spoke to AA before purchasing mine and they said that until you get past 600 whp (i.e. upgraded turbo), there's not much performance difference between the catted and catless.

Remember with the catted downpipe, you're using a higher flow cat along with eliminating the downstream cat in factory downpipe. That's removing quite a bit of restriction. Today my car made 372/466 on a mustang dyno with an AA catted downpipe if that helps with making your decision.

I agree with Active Autowerke. No power difference between catless and a high flow catted downpipe for stage 1 or stage 2 applications.
You might be able to get an additional 20 whp with catless on custom-tuned stage 2 map, but that's about it

 

[Twisted Tuning]

Catted or Catless wont make a difference in an OTS tune world. They will make a difference when pushing the engine and turbo to the max. If you don't plan on pushing the car. catted DP is fine. otherwise Catless is the way to go.

Food for thought, most OEM cats are 400cell cats, so if you're going to spend money on a catted downpipe, 200cel or less would be beneficial flow wise. if its a 300cel, i personally wouldnt even waste money on it since it will be so close to OEM flow restrictions.

 

[satindragon]

Even with a 300 cell cat, wouldn’t there be a substantial benefit because you’re also eliminating the second downstream cat?

 

[Twisted Tuning]

Even with a 300 cell cat, wouldn’t there be a substantial benefit because you’re also eliminating the second downstream cat?

with just a downpipe you're only eliminating one cat.

EDIT: oh, you're talking EURO cars with OPF and all that?

 

[satindragon]

Nah I’m talking US spec cars too. If you look in a stock downpipe, there’s a catalytic converters between the upstream and downstream O2.

There’s also a second one after the downstream O2 within the downpipe body. I figure that’s there to just further reduce emissions even though it’s efficacy isn’t being measured by the ECU?

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