View previous topic :: View next topic |
Author |
Message |
91RSVert Member
Joined: 16 May 2007 Posts: 2736 Location: AR
1991 Chevrolet Camaro RS
|
Posted: Tue Apr 22, 2014 3:42 am Post subject: suggested base timing |
|
|
Finally got my neighbors camaro running. It has alot more motor then I am use to dealing with.
406ci
HSR
proline heads
.525/.540 224/230 112lsa 108icl I think??
headers
cloyes hex adjust chain which I think ended up getting set at 1 advance.
7730 ecm with custom chip.
I put base timing at 7deg to get it running, fill fluids and check items. Seemed like it wanted more. IIRC stock is 6? We never got a chance to check old timing due to damaged gear. What would some of you suggest? _________________ 2008 GMC Z71
1991 Camaro RS Vert
1972 Jimmy 4x4
20ft Longhorn Car Hauler
|
|
Back to top |
|
|
Alphius Peanut
Joined: 05 Sep 2006 Posts: 2429 Location: Grand Mound
1984 Chevrolet Camaro Z/28
|
Posted: Tue Apr 22, 2014 6:00 am Post subject: |
|
|
You have to set the base timing to what it is set to in the tune to get the correct total timing at WOT and under cruise. There's no way for us to tell you what the guy's chip is set for.
If you don't have access to the value in the tune or paperwork from the tuner with the base timing spec then it's safest to assume they left the initial advance setting stock. So look up base timing for the ECU's original year and engine and set it to that.
If you feel like experimenting, the best you can do is play around with it until you think it runs right. The tune could be arbitrarily set for any base timing number regardless of any other timing curve/max timing value. We have no way of knowing what it is set to even given all the engine specs in the world. _________________ 84 Camaro Z28 - LS1/T56
85 Silverado - Low and Slow |
|
Back to top |
|
|
aaron_sK Member
Joined: 23 Jan 2006 Posts: 8834 Location: Back in beautiful Tacompton
1987 Chevrolet Camaro IROC-Z
|
Posted: Tue Apr 22, 2014 7:02 am Post subject: |
|
|
Alphius wrote: | You have to set the base timing to what it is set to in the tune ... There's no way for us to tell you what the guy's chip is set for. |
Agreed.
Alphius wrote: | If you feel like experimenting, the best you can do is play around with it until you think it runs right. |
Except for this. This is a terrible idea (sorry, Gabe ). That is a surefire way to ping and blow the engine up.
You need to set the timing to whatever offset the chip thinks it has. The only way to find that out is to read the chip. You then need to make all further modifications to timing in the tables themselves.
Who burned the chip? Was it tuned by mail, on the road, or on a dyno? Has anything (and I mean anything) been changed since the tune was done?
FWIW I would guess that this "custom" chip is a poor tune, and doesn't have enough initial, but probably has too much advance at high RPM. However that's just a gut feeling on my part. |
|
Back to top |
|
|
Twilightoptics Hardcore (12sec Club)
Joined: 13 Jan 2004 Posts: 9191 Location: Auburn , WA
1987 Chevrolet Camaro IROC-Z
|
Posted: Tue Apr 22, 2014 7:40 am Post subject: |
|
|
What these guys said.
Put it at 6btdc. Put a dial back light on it. See what the timing is commanded idling warmed up from the ecm. Set you light to tgat number. If the light flashes on zero you know the base in the chip is 6. If not look and do the math. If its within 1-2deg id leave it alone. _________________ A redline a day keeps the carbon away! |
|
Back to top |
|
|
Twilightoptics Hardcore (12sec Club)
Joined: 13 Jan 2004 Posts: 9191 Location: Auburn , WA
1987 Chevrolet Camaro IROC-Z
|
Posted: Tue Apr 22, 2014 7:42 am Post subject: |
|
|
Also thats not how you setup a cam. It needs to be degreed on the icl- intake centerline. Or you install it straight up marks pointinh at each other and hope. Cams have advance built in.if the gear is adjustable you damn well need to set it up properly and degree it. That could even be why you think it wants more timing. _________________ A redline a day keeps the carbon away! |
|
Back to top |
|
|
91RSVert Member
Joined: 16 May 2007 Posts: 2736 Location: AR
1991 Chevrolet Camaro RS
|
Posted: Tue Apr 22, 2014 1:14 pm Post subject: |
|
|
ok, makes sense. But there is no info on what it was before. He emailed the guy who setup the motor with many questions. He answered many of them, but this was not one of them.
The timing chain is what is adjustable. I didn't even know they made them. I tried setting it at 0, it came out to about 1.
I have it set at 7deg right now. Guess he needs to take it for a spin and see. I only have a basic timing light, nothing fancy. |
|
Back to top |
|
|
aaron_sK Member
Joined: 23 Jan 2006 Posts: 8834 Location: Back in beautiful Tacompton
1987 Chevrolet Camaro IROC-Z
|
Posted: Tue Apr 22, 2014 2:45 pm Post subject: |
|
|
I would find a new tuner if the guy wont even tell you what he speced for initial.
If you changed the cam you should have a new chip burned anyway. Speed density ftw. |
|
Back to top |
|
|
91RSVert Member
Joined: 16 May 2007 Posts: 2736 Location: AR
1991 Chevrolet Camaro RS
|
Posted: Tue Apr 22, 2014 6:06 pm Post subject: |
|
|
He bought the car already built. The fact that the PO/builder answered any questions was more then I expected.
I told him new cam=new chip. He has the equipment, just doesn't fully understand it. |
|
Back to top |
|
|
Alphius Peanut
Joined: 05 Sep 2006 Posts: 2429 Location: Grand Mound
1984 Chevrolet Camaro Z/28
|
Posted: Sat Apr 26, 2014 7:14 am Post subject: |
|
|
aaron_sK wrote: | Alphius wrote: | If you feel like experimenting, the best you can do is play around with it until you think it runs right. |
Except for this. This is a terrible idea (sorry, Gabe ). That is a surefire way to ping and blow the engine up. |
I have no idea of the levels of their redneckery down there. I presented the right way, then I presented the dumb and inefficent way. Life is all about options. _________________ 84 Camaro Z28 - LS1/T56
85 Silverado - Low and Slow |
|
Back to top |
|
|
|