best bang for buck- RP Cat or Unortho pulleys
 

Guys

Just trying to get a concensus here. My next mod will probaly be one of the two listed. RP cat goes for about $425 with gaskets etc and the Pulley set goes for about $250 uninstalled. I hear good and bad about both. Can't make up my mind. I have the RB catback but if the cat will give me another 8hp(as claimed) then it may win. But I cant find where the cat is giving 8hp or so consistantly. Same with the pullies--some like them and feel the differance--some dont. Would just removing the a/c belt(for track days) be just as good?
Olddragger :scratchhe

If you really want something that will have a performance gaing that you will feel. I will go with a final gear change.

probably hi flow cat, you save on weight and get a small increase in power. I don't think pulleys provide any hp gains.

od - I have them both installed. Definitely the high flow cat is the biggest bang. As for the pulleys, my throttle response is allot crisper now, and I find that the engine seems to rev easier. I like them both.

I currently have the REV8 installed, but she is coming off this weekend. :)

FWIW, I would +1^^^^^

Nemesis, what are you getting? I am droping my REV8 soon, too.

Did not say for fear of getting flamed, but I'm installing the RB Single.

i unfortunetly can't say that i picked up any power with the RP cat

Hey! That is funny that you said that. I just got back from a speed shop this afternoon to look into installing a single muffler axleback (off the REV8 midpipe extention.) I think I have desided to set up a appt. for...soon. Going with a magnaflow 14239 which is 12lbs. (dont tell anyone but I am going to copy RBs downturned tip to quiet down the MF straight thru muffler) Going to have no tips!!! Congrats. I think that is an excellent compromize between resonably high quality, good price and reasonable weight loss. No flames here.

ok 2 votes for the cat and slight ok for the pully's and one with didnt get nothing.
Hence my delimna--plus I cant spell
Olddragger

One works & the other one doesn't. This isn't a big V8 where you are removing a ton of weight in addition to massively underdriving the components (UR stated they are only undriving like 15%-20%). You are not taking out weight from a massive 15-20 lb. harmonic balancer. The pulleies together maybe add up to a few lbs.

It's 11% on the eccentric shaft with the UR :)

You know what's funny. The rx7store.net rx8 dual catback is the same weight as the RB single :)

RB mufflers must be damn heavy.

so rp cat/pipe is the go ahead?-- can the seat of the pants feel the differance?
Olddragger

For you Washington guys, maybe you should ask if the equipment comes with free rain tires for your car, or free scuba gear for yourselves.

I could when I installed mine. I'd recommend it any day of the week.

Definite seat of the pants feeling

(Fanman - I think I am growing gills to breath lately)

Ok then --sounds like I better tell my teenagers the bad news. No rolling stones concert for them--I'm a going to get the cat. Hope it sounds of with my rev8
OD

od

http://www.nemesis8.com/videos/RB+RP.wmv

Thanks Nem--does change the decibels a little doesnt it? Sounds good to me. More of a "present and accounted for" tone!
Olddragger

od,
Have you conversed with Charlie @ Mazcare on these options? If not, you may want to...

rp cat over the pullys. pullys don't do anything

well I've seen a number of dynos that say different, so which ones do you believe?

FWIW, SRMotorsports has their original pulley system on sale for $399, they recently came out with a new wide belt pulley system, looks like it adds two more ribs, they say 25% wider and prevents the water pump from slipping at high rpm

For just the muffler yes, but he whole thing with feeder pipe is 26 lb, my custom one is 9 lb and I bet it's just as quiet on the sound meter, one of their issues is the use 0.065 wall tube (16 Ga) because it's readily avalable but it's really overkill for a stainless system, 18 Ga is plenty adequate for a street system and a race system can get away with 20 Ga, for serious race 22 Ga Inconel 625 will give the best weight/performance

I'm presently building a street version with dual mufflers and tips as a present for a special friend that I think will come in around 16 lbs despite being stainless, should have it done within the next month

$639 ! :shocking: Holy Cow !

ok ur puleys be in tomorrow then i dyno them next weekend to give u guys a rx8 clum members dyno numbers on them

I don't know that it means anything, did your PCM readjust to them etc. blah blah blah ...

The RB single had to come off for daily street driving - way to loud with the RP midpipe. I'm back to the other heavy catback LOL

what it look like? i havent seen it yet...

**edit** jus checked.. eh.. looks kinda funky..to me

You know what? I think a lot of people are way too picky about dyno's. I can understand that there is a little difference in days done etc, but still. It's a good basline. I know the Renesis has incredible output for its size and everything, but still, dynos are pretty self evident.

I don't really trust vendor dynos. They have too much to gain for putting out higher numbers. A few of the things I bought, the vendor dynos said one thing, and they always registered drastically lower. I trust posters on this board, but when a product gets several dynos by people on the board so much the better. RX Tuner & Polak have much better methods of dynoing product. On several of their tests they literally leave the car in the same position on the dyno vs. some of these other vendor dynos where you notice that the seperate dynos were performed 6 months apart in completely different conditions & were not normalized/standardized.

interested to see the results here.
olddragger

hey Nem your pipes are pretty white--not carboned--you running lean?
Olddragger

Above 6200 I'm at 13.2 AFR with the CZ

That's an old pic I think. Right now they are dirty as hell. Over 30 days of rain and I can't keep the car clean. The pipes are filthy at the moment.

been there done that. I did like that side affect (less carbon)with my cz unit. Unfortunaly I didnt know enough about tuning to get the thing to work the way I wanted on the track--so I sold it. I still think in the hands of a knowledgable person it can be made to work well. 13.2 is nice and conservative but will get you some gains--good work
olddragger

Well, just got back from the dyno, and with the cz and pulleys, I broke 200 corrected at the wheels. I should have the data log file tonight.

Dude, great! cant wait for the graph. So did you happen to do a pre-pulley, post-pulley but pre-cz, then post pulley+post-cz?

Not exactly... :)

https://www.rx8club.com/rx-8-multimedia-photo-gallery-6/northwest-rx8-dyno-day-pics-etc-81240/

Post 7

nice, I gotta think the pulleys are responsible for some of that, more than some people here claim

This is purely questionable. Until somebody baselines, installs pullies, then dynos again you can't make that assumption. Or runs a dyno that normlizes for condition. Nemesis was already in the 190's from his previous mods. So getting 200+ whp from even just his CZ & tuning would be easyily understandable. With some of the other cars, the CZ was delivering 12-25 whp with just the unit itself.

^^^^Pulley H8er!!!:spank: :bootyshak :nono:

:)

I've seen planty of CZ units not make any power, even tuned the supplier has some pretty wild claims IMO

note he said the ignition was zeroed and a base fuel map, so in this case it wasn't tuned at all

Sorry I could not give a comparison dyno - just did not have the time. But TeamRX8 is right - it was not tuned completely. The ECU was pulling timing, so I need to get my wideband installed and tune this setup with both fuel and ignition maps.

I agree that CZ's claims were pretty wild. I did question other people when they had a 25 hp gain with stage 1 & a 40 hp claim with stage 2. But 12-25 hp (tuned) seems about the norm (norm being a very wide gap as you can see). And I did get 1-2 hp from my pullies.

Nemesis, good job. Congratulations on getting over the 200 whp hump NA.

Thanks - I think I can get better with proper tuning. After this NA setup is complete with the proper header, I'll run it until the blowers are all out, then go Supercharged Renesis :)

I'll drive down the Coast and look you up for some R&R in the Sun

FYI, I may offer my RE Amemiya header up for sale soon ...