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-   -   engine doesn't want to rev past 6500rpm (https://www.rx8club.com/series-i-engine-tuning-forum-63/engine-doesnt-want-rev-past-6500rpm-190009/)

dieselsdad 01-26-2010 04:33 PM

engine doesn't want to rev past 6500rpm
 
Got the BHR ignition kit in and installed it today. Definately fixed the dead coils issue. Car runs great on the street, pulls well, but on the dyno the motor doesn't want to pull over 6000-6500rpm. Fuel trims look good, spark looks good. We're thinking maybe the apv valves aren't wanting to open correctly?

The car is a 2005 with AEM intake, BHR ignition, brand new plugs, HKS single side exhaust.

Any ideas? We're here at the dyno looking for answers (time is not an issue so don't fret).

Jedi54 01-26-2010 04:35 PM

bad cat?

The dead coil you mentioned could have prematurely killed your catalytic

dieselsdad 01-26-2010 04:39 PM

Thought about that. Am perplexed by it running well on the street. The rollers on the dyno are VERY heavy so it's possible. I figured the dead cat would be consistent with running on the street though.

Mazurfer 01-26-2010 05:14 PM

The fact that it happens at 6500 may be a clue!

APV valve opens providing more air to the system at 6500rpms. It is possible that it isn't opening as it should and some ZoomZoom cleaner might fix it.

I know this is stupid but.................you know that the PCM won't let you go above 6500 until you are at proper temp right?

And............also kinda stupid in this case, but I read somewhere that "When the car is not in motion there is no extra air to come into the engine so the SSV doesn't open." I take this as meaning in neutral in your particular case, it won't do it either......but I'm sure you aren't in neutral at this time. Of course......it could be the CAT as Jorge points out!

dieselsdad 01-26-2010 05:34 PM

Jedi was right.........as always.

Dead cat. Spit pieces out when I pulled it off.

Racing Beat test pipe fixed that.

We'll see what dyno tuning does later throughout the week.

Jedi54 01-26-2010 05:39 PM

glad I could help! :D:
although, I don't imagine removing a RED HOT cat off a car that was just on a dyno was a whole lot of fun.

let us know how the dyno numbers come out. Are you tuning with the AP? is the car N/A or FI?

Razz1 01-26-2010 06:24 PM

Poor CAT...

Rest in peace.

Mazurfer 01-26-2010 06:25 PM

Another cat uses up it's nine lives!

RIWWP 01-26-2010 06:27 PM

There has been alot of dead cats recently.


Who let the dogs out?

Jon316G 01-26-2010 06:29 PM


Originally Posted by Mazurfer (Post 3403578)
SSV valve opens providing more air to the system at 6500rpms.

I know its irrelevant to this topic since the OP already figured-out the problem, but wanted to correct this.
Mazurfer- You're thinking of the APV which opens above 6250RPM. The SSV opens above 3250RPM.
OK... I'm done ;)

Mazurfer 01-26-2010 06:37 PM


Originally Posted by Jon316G (Post 3403684)
I know its irrelevant to this topic since the OP already figured-out the problem, but wanted to correct this.
Mazurfer- You're thinking of the APV which opens above 6250RPM. The SSV opens above 3250RPM.
OK... I'm done ;)

Oooooops! I fixed it.........sometimes I just type too fast or get distracted in the middle of something.

dieselsdad 01-26-2010 09:01 PM

Sorry, had a 2 hour drive home.

Like I said, the cat was the issue. It blew chunks all over the floor. Didn't get to make another dyno run tonight but did take the car around the block before getting it ready for tomm. Seat of the pants is WAY better.....and louder (I knew to expect this, I have several rotary racecars). It's harder to say how much EXTRA power I'm making catless as it was so sick before hand, dead coils and plugged cat. We'll see more numbers this week. I figure it will finish up tomm but maybe Thursday.

The car is NA and is being tuned on some superflow rollers (which weigh 4800 pounds by the way).

I'll keep you posted as we see more results.

Jedi54 01-26-2010 09:13 PM

diesel: what engine management are you using to tune the car?
AccessPORT? E-manage? Hymee ProTuner?

dieselsdad 01-26-2010 09:45 PM

SuperFlow all-wheel dyno and some proprietery tuning software. Doesn't belong to me so sorry I don't have more info.

I do have an AP and AccessTuner but haven't used it yet as I wanted to fix the coil issue first. Then this oppottunity came along to be tuned so........

dieselsdad 01-28-2010 09:06 AM

The first pull after replacing the dead cat with a mid pipe made OVER 100 hp more. I ROCK. Too bad the pulls before the dead cat were so miserable.

We'll see how we fare over the next few days.


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