Thanks Jason. It does smooth out a bit, but a touch of the gas leaves it diving and threatening to stall. Here’s a video that starts 75 seconds after a cold start. The car ran a bit smoother on this second start, with a bit less hunting. The new chip raised the idle speed to 1,000 RPM’s, which seems to help.

The idle does settle in once the car is well warmed up. But even with a hot engine (driving with former chip) the car threatened to stall every time I stopped the car. If you can ease into the stop and let the RPM’s down slowly, you can usually avoid stalling. But a quick stop pretty much assures a stall. I did a few rolling starts last weekend while coasting after a stall. Fun times. O

Thanks for any input. Here’s the video 75 seconds after start (at the end my daughter was just saying, “I think you just scared the turkeys” - Damn turkeys are everywhere this spring).

 

Here’s some helpful information from Steve Wong that describes what went into mapping the custom chip for the B&B headers, LWF and especially the modified 993 SS cams.

“In your case, the 993 Super Sport cams you have installed flow much higher through the rpm range vs the stock cams, that additional fueling needs to be calibrated in or the engine can run lean at the upper rpms. In addition the lumpiness of the cams, combined with your lightweight flywheel is a combination that is almost a sure fire formula for hard and consistent stalling. So further aggressive idle stabilization modifications need to be made to help mitigate and minimize the problem, including raising the idle speed, changing the injector turn on rate on decel, and reshaping the entire idle ignition timing curve. Any other modifications and specifications you provide and request, such as combined to the B&B headers, and tuning for 93 and up octane are all factored in and used to calculate your final mapping,”

 

The next time you take it out and after the engine has warmed up, put the CCU temperature to red with the blower speed to 1 and see if that reduces the stalling that occurs on throttle overrun (with the car in motion).

 

Incredible story, thank you so much or sharing the journey with us.

What is name of the paint shop?

 

I recently had a similar weber ss cam installed in my 95 993 which also has lwfw, cat delete (stock headers). Very happy with the way the car pulls. I ponied up for "custom" chip from Steve and dealing with stalling as well. The car occasionally takes longer to crank over and can occasionally idle hunt after coming to a stop, but doesn't seem as bad as Foxman's. Biggest annoyance for me is stalling when coming to a stop. It will stall unless I let the revs get down to 1.5k or so before pressing in the clutch. I can work around with driving style, but for the price of the custom chip I would expect little to no stalling issues.

Not to mention, I bought the off the shelf 93 octane chip($) then when I added lwfw had it re-written($). This time I was told I would need a whole new chip and it would have to be custom($$$). My point is I have spent a lot on 911chips and still stalling.

 

I’m in total agreement the car needs new wheels. I pulled the trigger on a set of BBS E- 88’s from Carnewal a few months ago. It should represent an additional 25 lbs in weight savings (unsprung).

The paint shop is my garage. Though I do use Mike up in Seabrook New Hampshire for any large tasks like the new roof and carbon frunk. Great guy if you’re not in a rush, and very reasonably priced.

Thanks for your input Craina, that’s really very helpful. I also had to buy a whole new “custom” chip for $795 after spending $500 on the prior Wong chip with no credit. The good news is that the custom chip includes a free re-write so if you make any adjustments you can send it back free of charge to be re-mapped.

Im jealous that you only have to bring the RPM’s down to 1,500 to avoid the stall. I have to keep off the clutch and wait until the RPM’s drop below 1,000, or she’s sure to stall.

Once my car car warms up, at least with the former Wong chip there was no idle searching.

Have you tried porting out the damn in the idle control valve? Steve Wong sent a write up on this with the chip, so I’m guessing the chip alone won’t cure the problem. That will be my next project.

Thanks again for your feedback, good to know there’s a few of us out there working through this.

 

Yeah, I usually wait until 1200rpm or so before touching the clutch. I wish there were more of a pattern. Sometimes I will kick the clutch in at 2-3k and it finds idle. Other times I kick it in at 1.5k and stall. I am hoping the car will learn/adapt. I had a day earlier this week, after the car had sat for two days, with no stalls at all. I thought it was adapting. Next day back to stalling. I have not ported the ICV. I will look into that. I will report back if there are any improvements.

All that said, I am pretty pleased with the new power. My engine was coming out for maintenance and I just had to do a little hot rodding but could not justify a full "build".

 

Win, win, win!

 

My Indy was kind enough to take some photos while refurbishing the transmission. I'll start with a few before and after photos:


Before

After

Before

After

Before (open diff)

After (Guards LSD)

 

Here's a dive down with assorted photos during the breakdown and clean-up. Note the attention to detail. That is why Bill Pfister is my mechanic.

 

I'm looking forward to seeing this car at one of our local tracks this season! (fingers crossed...)

 

 

 

Fin

 

Thanks Locker537, I'm itching to get the car out on the track and see how it performs. Palmer opens next week, but Wilbur needs a new pair of shoes, and some fresh tires. I'm waiting patiently for the new BBS wheels. Hope to see you soon!