: New flywheel installed. Tune needed?



onestout
09-25-13, 10:51 PM
I have a 2006 with a good cam in it, not exactly sure what, bought it that way. I replaced the clutch with an aluminum flywheel and McLeod twin disc and now it has all kinds of idling issues. My fuel tabs are maxxing out when cold and it really runs like crap. Has anyone else needed to do a tune after a lighter clutch and flywheel install?

HAMSTAR
09-25-13, 11:06 PM
***This part deleted due to early morning idiocy.***

What specific problems are you having?

FuzzyLogic
09-25-13, 11:46 PM
That was the FAST 102, Hamstar. You don't need a retune to account for a clutch, although your tuner can definitely help if your engine RPMs tend to drop when you clutch in.

onestout
09-25-13, 11:52 PM
very erratic idle and it's kicking out codes and running really lean. It's trying to dump in as much fuel as it can and it's still not enough. No vacuum leak and all the grounds are back where they are supposed to be.

pato
09-26-13, 12:29 AM
It is not the clutch, there's something else either disconnected or broken, IMO.
Start by checking oxygen sensors, MAP sensor, and cam position sensor. The last 2 are behind the intake manifold and could be disconnected or broken when loosening or tightening the top bellhousing bolt.

lollygagger8
09-26-13, 11:15 AM
How light is your FW?

After I installed my heads/cam/102 fast and 102 TB, I had idle issues to where my 18 lb FW would dip below 1k RPM 3 times while coming to a stop before finding idle. I never had that problem before the H/C. The Tuner said it was the lightened FW and had a helluva time tuning around it.

HAMSTAR
09-26-13, 11:43 AM
i think the combination and lightweight flywheel and fast102 is what causes the difficulty. the heavy flywheel acts as kind of a mechanical throttle follower. the FAST102 is so big, flows so well that at lower airflow risks turbulence if the baseline airflow, throttle follower/decay rate are not really dialed in.

that said, i think OP does not have a fast 102, so this is unlikely to be an issue for him.

FuzzyLogic
09-26-13, 01:15 PM
The problem is that every degree you open a 102mm throttle body is equivalent to several degrees on a 90mm or smaller throttle body. As a result, controlling A/F at low engine loads becomes much more difficult. Most tuners will blame everything on the car before they blame themselves for a lack of technical competence. If you tell them that you have a lightweight flywheel, they'll blame the flywheel. If you don't tell them that, they'll blame the throttle body. I know for a fact that skilled tuners are able to handle a 102mm throttle body, but they're the exception, not the rule.

PISNUOFF
09-26-13, 01:26 PM
How light is your FW?

After I installed my heads/cam/102 fast and 102 TB, I had idle issues to where my 18 lb FW would dip below 1k RPM 3 times while coming to a stop before finding idle. I never had that problem before the H/C. The Tuner said it was the lightened FW and had a helluva time tuning around it.

RAF calibrations and adaptive/proportional idle controls is what fixed yours. The light weight flywheel only contributed to the rpms falling too fast and the computer compensating incorrectly.


I have a 2006 with a good cam in it, not exactly sure what, bought it that way. I replaced the clutch with an aluminum flywheel and McLeod twin disc and now it has all kinds of idling issues. My fuel tabs are maxxing out when cold and it really runs like crap. Has anyone else needed to do a tune after a lighter clutch and flywheel install?

Sounds exactly like the O2 sensors are plugged in backwards or not plugged in at all. Certainly a lightweight flywheel would NOT cause those issues.

onestout
09-26-13, 02:37 PM
Thanks for the replys, I'll check out the O2 and other sensors. I know this thing was almost a bigger pain than pulling the trans in the vet, maybe something did get broken or plugged in wrong.

HAMSTAR
09-26-13, 02:40 PM
The problem is that every degree you open a 102mm throttle body is equivalent to several degrees on a 90mm or smaller throttle body. As a result, controlling A/F at low engine loads becomes much more difficult. Most tuners will blame everything on the car before they blame themselves for a lack of technical competence. If you tell them that you have a lightweight flywheel, they'll blame the flywheel. If you don't tell them that, they'll blame the throttle body. I know for a fact that skilled tuners are able to handle a 102mm throttle body, but they're the exception, not the rule.

I wish I'd bought HPtuners and started doing my own tuning long ago.

FuzzyLogic
09-26-13, 04:26 PM
I wish I'd bought HPtuners and started doing my own tuning long ago.

I know. I'm debating buying it now, but I already don't have enough time to simply install all of the parts in my apartment, much less experiment with engine tuning.

philistine
09-26-13, 05:44 PM
I find it cheaper to self tune using datalogs. In the long run, you save money. HP tuners and the PLX-DM6 is right around the corner for my next purchase.

lollygagger8
09-27-13, 11:44 AM
The problem is that every degree you open a 102mm throttle body is equivalent to several degrees on a 90mm or smaller throttle body. As a result, controlling A/F at low engine loads becomes much more difficult. Most tuners will blame everything on the car before they blame themselves for a lack of technical competence. If you tell them that you have a lightweight flywheel, they'll blame the flywheel. If you don't tell them that, they'll blame the throttle body. I know for a fact that skilled tuners are able to handle a 102mm throttle body, but they're the exception, not the rule.

TunedbyFrost doesn't know what he's doing?

kw3kw
09-27-13, 07:41 PM
I may be way off with this, but isn't there a crankshaft position sensor or some other sensor located in the flywheel area ?