Hp tuners and cam surge

**knappbunch** · 03-23-2009, 06:39 AM

Have a new motor (see sig) heve some lock up chatter with the converter at bout 50 to 55 mph and also have surging at idle and part throttle under load. How can I aproach this with my tuner? what are we looking for? Also from 25-30 mph has surging. It also stumbles right off idle a liitle.

**Quik** · 03-23-2009, 06:59 AM

look at theVE table and dial that in before you go any further

**knappbunch** · 03-23-2009, 07:44 AM

can you explain ve table so i can communicate with tuner as to what I am looking for.

**Frost** · 03-23-2009, 08:08 AM

You won't have to tell your tuner what to tune, just the symptoms.

**knappbunch** · 03-23-2009, 08:12 AM

I hear ya! looking to get myself a little more informed and learn as i go so communication is easier. Car will be tuned great and the tuner i have has already tuned it great just getting bugs out.

**Frost** · 03-23-2009, 08:38 AM

Originally Posted by knappbunch

I hear ya! looking to get myself a little more informed and learn as i go so communication is easier. Car will be tuned great and the tuner i have has already tuned it great just getting bugs out.

Hey Travis, I'm sure that you are in good hands

To answer to the post though;
Things that cause cam surge in order of appearance for the cars I tune:
1. too much airflow; whether base airflow is too high or the throttle cracker is putting too much in, or there is too much throttle follower active
2. affected area timing is too high (not uncommon either, sometimes it takes a valley in the spark maps around the affected area to get rid of it)
3. AFR. I say AFR last because most people use closed loop, and closed loop keeps the AFR near stoich.

As a part of tuning for a car like yours, lockup in third is disabled, and sometimes the lock/unlock settings are tweaked to keep it from staying locked up too low which contributes. Sometimes (not often but it definitely happens) the above 3 items just can't get rid of it or it down low enough and the TC lockup adjustment can hide the rest of it.

**knappbunch** · 03-23-2009, 08:44 AM

If a car you were tuning was locking up at around 50 to 55 mph what would you do to fix it?

**Frost** · 03-23-2009, 09:14 AM

There is no absolute answer to the fix; you have to find what works for that combination. Sounds like lockup/unlock is quite high already, so I would work through the list I posted above.