WedsSport RevCat

[szymonsta]

i have recently purchased a new WedsSport RevCatalyzer for my DC2R.
it was installed yesterday, replacing the standard JDM-spec catalyzer i was running previously.

standard jdm cat


WedsSport cat


my exhaust setups have gone through several phases:
1) standard
2) '98-00spec JDM 4-1 exh mani, '98-00spec JDM cat, Fujitsubo Powergetter
3) M-Bit 4-2-1 exh mani, '98-00spec JDM cat, Fujitsubo Powergetter
4) M-Bit 4-2-1 exh mani, WedsSport cat, Fujitsubo Powergetter

only other engine mods are Mugen Baffled Sump, Mugen Thermostat, Koyo Radiator and Mugen N1 ecu.

i havn't had a chance to go for a proper drive with the latest setup yet, but there's no noticeable difference at daily-commute speeds. review coming shortly..

[kavehman]

To me it looks like the step down in width coming out of the cat is a major bottleneck.

I don't think it will make any difference what cat you put on there, with a bottle neck like that nothing will help it.

Why didn't you just go with the same diameter piping all the way through ?

I would think something like what I have done would be more beneficial, although I have yet to dyno it.

[tinkerbell]

To me it looks like the step down in width coming out of the cat is a major bottleneck.

i wouldn't say that that was "major" really?

particularly since the gas would have just hit the honeycomb and slowed down a touch, so a step taper might be incorporated to retain the gas speed?

maybe they did it that way on purpose?

[tinkerbell]

and yours will work fine too...

[szymonsta]

the weds sport cat's exit piping is 60.5mm diameter, which is the same diameter as the fujitsubo powergetter. the inlet piping is slightly larger than the 60.5mm final piping on the M-Bit 4-2-1's.
care to explain where the 'major bottleneck' is in my setup?

when i get a chance to go for a proper drive i will be able to comment on whether i feel any difference on the butt-dyno. any definite result will have to wait until i dyno it next..

there were several reasons why i chose the WedsSport cat, including:
-i have a soft spot for japanese made high-quality 'brand name' stuff
-i beleive it will improve power while still performing its function, going de-cat is a bit risky for a daily-driver in my opinion
-it is a direct bolt-on, i havn't found any 'custom' shops in adelaide who's work has been of a standard i would be happy with.
-i managed to get it at a very good price, considering theyre about Y650k retail..in fact it was cheaper than going for a metalcat/(bodgy magnaflow/insert crappy no-name chinese cat which stinks of egg and doesn't actually clean the exhaust gases, let alone provide better flow) and then having it custom-made to fit my car

[kavehman]

When I was speaking to I think Dave at SMSP ( forget his name) he was telling me that the biggest problem with the DC2R piping was the bottle neck created right after tha Cat on the B pipe.

If you look at the stock piping there is a bit of a bend in it which reduces piping sixe to 2 inch. I assume this is there to aid cold start's and to get the cat up to operating temperature quicker.

His advice was to do 2.5" piping all the way through, I can't find anyone that seems to disagree with this ?

Anyways it would be interesting if you had dynos of before and after.

[kavehman]

The outlet looks a lot smaller than the inlet diameter. Can you confirm that they are both the same ?

i couldn't find the post but there is a great one with flow test data on it for Cat's

Found it, check this out to see how perhaps urs may perform if you know whether it is a 200 cell or 300 cell cat ? im thinking its probably closer to 400.

http://www.honda-tech.com/zerothread?id=1323923

[szymonsta]

The outlet looks a lot smaller than the inlet diameter. Can you confirm that they are both the same ?

the weds sport cat's exit piping is 60.5mm diameter, which is the same diameter as the fujitsubo powergetter. the inlet piping is slightly larger than the 60.5mm final piping on the M-Bit 4-2-1's.

Found it, check this out to see how perhaps urs may perform if you know whether it is a 200 cell or 300 cell cat ? im thinking its probably closer to 400.

http://www.honda-tech.com/zerothread?id=1323923

the WedsSport page with details of the cat is here:
http://translate.google.com.au/trans...%3Den%26sa%3DG

unfortunately the japlish doesnt clarify whether its 200 or 400cpsi, however according to my HyperRev its 200cpsi..

[szymonsta]

When I was speaking to I think Dave at SMSP ( forget his name) he was telling me that the biggest problem with the DC2R piping was the bottle neck created right after tha Cat on the B pipe.

If you look at the stock piping there is a bit of a bend in it which reduces piping sixe to 2 inch. I assume this is there to aid cold start's and to get the cat up to operating temperature quicker.

His advice was to do 2.5" piping all the way through, I can't find anyone that seems to disagree with this ?

Anyways it would be interesting if you had dynos of before and after.

if you read my post you'll see it says the smallest diameter of the weds cat is 60.5mm (on the exit side) which is the same as the diameter of the fujitsubo catback exhaust.
as i said before i can't see any 'bottleneck' in my current exhaust system setup?

and if you read my previus post you'll see it says the inlet to the cat is a larger diameter to the exit diameter.

for n/a dc2r, most japanese honda tuners utilise 60 or 60.5mm dia. final exh. mani (mugen,m-bit, j's, toda, etc.), and same diameter cat-back. if they run a de-cat pipe, it is 60 or 60.5mm (Vision, J's, BackyardSpecial).

so if my exh. manifold's tertiary runner is 60.5mm, the weds cat has an inlet of slightly larger than 60.5 and MINIMUM diameter of 60.5mm at the exit, and the Fujitsubo Powergetter has a diameter of 60.5mm...where is the bottleneck you speak of?

[K.C.]

he meant the increase in cross sectional area will slow the gas down? ie Bernoulli thingy?
or the step up and step down diameter causes turbulence?

[FunkyR]

Looks hot!

Kaveh - Given those measurements I dont think there's a bottle neck. How can you tell the cat is 400 cell by look at the outside of it? And no, I'm not interested in knowing about your cat.

[kavehman]

Mate i'm not trying to pick a fight with you, maybe it's an optical illusion in the photo but to me it looks like the outlet is smaller in diameter than the inlest.

And I think you just clarified that there the same diameter.



BTW: I can't tell how many Cell it is, I was asking how many cell it was.

I was posting that info as I thought it may have been beneficial to the original poster in determining how well it flows comapred to the JDM Cat, besides if anyone searches for this in the future that thread link is there.

[szymonsta]

as ive stated a few times now kaveh, the inlet IS larger than the outlet..
thanks for your input anyway.

review to come when i have a chance to go for a nice drive..

[kavehman]

comprehension owns me

[00dc2]

lol