Miata Turbo Forum - Boost cars, acquire cats.

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-   Prefabbed Turbo Kits (https://www.miataturbo.net/prefabbed-turbo-kits-3/)
-   -   ACT XT, Fidanza flywheel, gutted cat ZOMG! (https://www.miataturbo.net/prefabbed-turbo-kits-3/act-xt-fidanza-flywheel-gutted-cat-zomg-14357/)

Bryce 11-29-2007 01:01 AM

ACT XT, Fidanza flywheel, gutted cat ZOMG!
 
I finished with the install earlier today. I couldn't get the nuts off the catalytic converter to remove the downpipe so I dropped the entire exhaust.
I had a coworker come over to help me do some stud excavation on the cat flanges, both sides. In the process we knocked some stuff lose inside the cat so I decided to gut it and buy a high flow one come smog testing time.
Gutting a cat is something everyone should do once in their life, it's a good form of stress relief. :)

I installed an ACT XT (Overkill, but hey you never know when I might randomly pick up megasquirt) with street disc and an 8lb Fidanza flywheel.
Anyways the rest of the install went without any hitches. I drove around for a bit without no exhaust after the downpipe just to see how it was and boy was that exciting. I love the ominous whistle of the turbine in the exhaust. Too bad I couldn't keep it that way lest I get pulled over by the law.

Had my fun, bolted up the rest of the exhaust and I was surprised to see the performance was still there, first gear actually became useless past 5k rpms. So between the flywheel and gutted cat I gained a massive performance increase, which one is to blame the most?

I love the flywheel so far and I've already put 50 miles on the new setup today. It gives a much more crisp throttle response perfect for heel-toe rev matching. I also switched to Pennzoil synchromesh transmission fluid from Redline MTL.

I have the wastegate actuator rod tightened all the way to make up the lost boost from the intercooler and made 5.5 psi (on the highway) before I gutted the cat. Now on the highway it gets up to 7! Is this ok or should I loosen the wastegate rod some?

I had to adjust the freeplay in the clutch at first to be able to shift out of neutral. I know this clutch is supposed to engage low, but I think it seems too low, the instant I move my foot it's already engaging. I sometimes have trouble shifting into gears even though I have my foot burried into the floor. I have the freeplay adjustment rod turned out as hard as I can with my fingers, is it ok to use a wrench on it or would that preload the throwout bearing? Or is there another adjustment to increase clutch travel?

Well that's all the questions I have for now :)

Savington 11-29-2007 01:14 AM

I'd back it down. Less restriction in the exhaust = more flow = more restriction in the intake = more boost

The ACT XT engages low. Just something you have to deal with. :(

Bryce 11-29-2007 01:17 AM

Alright, I'll back it down.

I assume it should'nt be so low that I can't shift sometimes :dunno:

spike 11-29-2007 01:51 AM

Word of advice,you might want to break the clutch in before you start driving it hard.

Bryce 11-29-2007 01:52 AM

Yep I'm being uber-careful with it. I have to anyways cuz I'm still on the 1.6 diff :(

jif 11-29-2007 03:13 AM

the engagement point should move up a bit over the next 1k km or so ...

BenR 11-29-2007 10:24 AM


Originally Posted by Bryceness (Post 179205)
I have the wastegate actuator rod tightened all the way to make up the lost boost from the intercooler and made 5.5 psi (on the highway) before I gutted the cat. Now on the highway it gets up to 7! Is this ok or should I loosen the wastegate rod some?


Install your LC-1 and answer your own question. :P

Bryce 11-29-2007 12:54 PM

Mmk thanks for the input everyone. I'm digging the new setup :)

Got pics of where you might put the bung on a stock downpipe? I've been told 10 inches upstream of the cat, but where? I'm wondering how I'll get a wrench on it.

col 11-29-2007 04:34 PM

I've heard the clutch problem over and over again.
Has anyone had the slave cylinder re-sleeved to the next smaller size?
This should increase the length of travel of the actuating rod and at the same time give a softer pedal. I intend to get this same clutch but don't want the low pedal.
This would be the logical fix to me but I would like peoples opinions.
Thanks Col

Bryce 11-29-2007 05:20 PM

How about the braided stainless steel clutch line that replaces the stock rubber bits. Like the one from Thompson Automotive. That'll put more of your work into working the slave cylinder instead of expanding like the stock rubber lines.

mazda/nissan 11-29-2007 05:25 PM


Originally Posted by Bryceness (Post 179205)
I had a coworker come over to help me do some stud excavation

:ky:

p.s.
do you get backfiring issues with the gutted cat? I know a person that nearly blew his muffler off due to a gutted cat.

Bryce 11-29-2007 05:32 PM


Originally Posted by mazda/nissan (Post 179451)
:ky:

p.s.
do you get backfiring issues with the gutted cat? I know a person that nearly blew his muffler off due to a gutted cat.

Lol. Nope don't have any backfiring even with the open downpipe. Turbo spools what seems to be 200 rpms earlier and I've got a bit more of that lovely turbine whistle in the exhaust.

spike 11-29-2007 05:48 PM


Originally Posted by mazda/nissan (Post 179451)
:ky:

p.s.
do you get backfiring issues with the gutted cat? I know a person that nearly blew his muffler off due to a gutted cat.

I'm running a test pipe and I get backfire along with blue flames.:bigtu:

Mach929 11-29-2007 05:59 PM

the clutch will break in and engagement will move up so i'd leave it for a 1000miles or so

Bryce 11-29-2007 07:20 PM

Ok, new problem, or should I say annoyance. I'm getting a fairly loud cricket sound related to engine rpm. It's clearly audible in the cockpit with the top up at 60mph. It only makes this sound when the clutch pedal is out. If I push the clutch in just slightly, it changes timbre and goes away.

spike 11-29-2007 07:31 PM

^ sounds like you have the infamous ACT clutch squeal

Bryce 11-29-2007 08:13 PM


Originally Posted by spike (Post 179514)
^ sounds like you have the infamous ACT clutch squeal

Great... Known fixes? I've got a 200 mile round trip tomorrow :(

cyee 11-29-2007 09:04 PM


Originally Posted by Bryceness (Post 179536)
Great... Known fixes? I've got a 200 mile round trip tomorrow :(

Put a glob of grease on the clutch slave rod tip where it meets the clutch release fork. you can get at it easily from the passenger side front wheel well.

Bryce 11-29-2007 09:05 PM


Originally Posted by cyee (Post 179558)
Put a glob of grease on the clutch slave rod tip where it meets the clutch release fork. you can get at it easily from the passenger side front wheel well.

Wow, I literally read that just now on m.net as you made this post. I'll do that and report back.

Bryce 11-29-2007 10:00 PM

Sprayed some white lithium grease on it. Drove it around the block and so far no squeaking. :)


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