02sierraz71_5.3

iTrader: (2)

Im specing a cam with the stock stall speed of 1300 for my truck. I like the idea of running alot of overlap with relatively smaller durations under 212 on the intake and IVC of 33, with a bigger exhaust lobe. The problem Im wondering about is having too much overlap and having to raise the idle too much and tweak the air tables. Im thinking I can have problem of it pulling too much at a stop light and being hard to stop, keep stationary or being very jerky.

Has anyone run into this problem with a very low stall speed and aggressive cam on an A4?
recommendations?

Ragtop 99

iTrader: (7)

The challenge is that a stock stall limits your idle speed to about 700 rpm before you are fighting it at a stoplight. You can get a decent size cam to idle at that speed, but yes it will take some effort tuning. If you are unwilling to tune the cam, then stay small. Maybe something like a 206/218 114 111 would do the trick. With some basic tuning you could step up to 210/218 112 109.

Patrick G

iTrader: (14)

I agree with Ragtop. You are really compromising your cam selection by staying with the stock stall. A better approach would be to get a Trailblazer L-6 torque converter installed. They're very cheap to buy and will still give you a high degree of towing, but they'll stall about 500 rpm more than stock. Just the ticket for running the beefier cam, but keeping stock driving manners.

If you stick with the stock stall, you'll most likely be fighting against the brake at idle unless you are a MASTER tuner.

Trail 70

We ran a 230-224 on a 114 lobe in a 2000 ss with stock converter. With a very good tuner we got it to idle a 650-700 in gear.

09CPTN

iTrader: (5)

Will this be an issue for me as well in my 1998 T/A? I want to run my stock stall with my 230/232 .595.598 on a 114 lsa.

bjamick

iTrader: (31)

Why does everybody forget all about the stall when doing a cam. How can you take full advantage of the cam without a stall. You can't...Atleast get like a 2500 stall or something along those lines and its not to much.

Patrick G

iTrader: (14)

LOL! Good luck. Your car will be an absolute turd with a stock stall and a cam that big. You might even be slower in the 1/4 than with the stock cam....seriously!

onebadrubi

I think he had a tci but it took out his tranny and now doesnt want to replace the converter.

Ragtop 99

iTrader: (7)

Probably had a good exhaust to run that reverse split. The extra backpressure of a stock exhaust would make a cam of similar overlap tougher to tune for a 700 rpm idle.

bjamick

iTrader: (31)

I doubt your car will even idle, and it will surge like hell just an FYI. But go for it man

Ragtop 99

iTrader: (7)

stock stall AND no headers (per your sig)?

02sierraz71_5.3

iTrader: (2)

Ive currently got the stock stall in with an lpe gt2-5 222/222 112/112 it idles at 700 and has more overlap than the new cam Im specing. But I do notice some drivability issues at low speed when vacuum is pulled. Im not worried about the tuning just dont want a cam that is be impossible to stop. At 800 this one definately pulls on the brakes and tends to be jerky, I cant imagine with a cam that actually makes good tq down there how much of a pain it would be.

Does anyone have a rule of thumb they go by like dont go more than -5 @.05 overlap with a stock stall?

02sierraz71_5.3

iTrader: (2)

Im thinking more along the lines of 212/218 110/108 puts the VE's just about perfect

Ragtop 99

iTrader: (7)

The advantage of 210* or 214* is you can use an XFI intake lobe and gain some real area under the curve compared with a 212 XE lobe. The XFI tend to run big so a 210 will be probably be a 212 when it is all said and done.

The 110 LSA will make great torque but I'd be concerned that those VEs will run out of breath a bit early on the top end.

With stock manifolds at -5 overlap, a 210/224 111 109 might be worth considering. However,given where you are coming from (IVC=43), doing a 210/224 112 111 is another choice. That's still a huge advance in IVC (IVC = 36), but it will still have some top end left in it and at -7 overlap your jerkiness should be easily tuned out.

02sierraz71_5.3

iTrader: (2)

Ive got thorley headers and I made a custom 2.5 flowmaster y pipe into a single 3" magnaflow, I run a cutout at the track.
I was thinking about a 210/220 but wondered about the big split.

Do you have a dyno of your cam?

Ragtop 99

iTrader: (7)

My cam made 344 on a mustang dyno on the stock exhaust. very flat torque curve and go throttle response even at 2000 rpm.

I agree that with a good exhaust, you can run less exhaust duration. I didn't see it in your sig. Given what you just described, a 214/220 111 109 would be something to consider. I don't know how fast the LPE lobe ramps are, but they probably aren't as fast an the combo of an XFI/Xer, so that will help idle a bit too. Doing it on a 112 LSA would bring it down to -7 overlap and ensure a clean tune.

09CPTN

iTrader: (5)

No headers, YET. I will have full bolt-ons, possibly before the cam install. Interesting that noone mentioned this to me before. I was under the impression that lots of people were running cam/bolt-on cars with the stock stall with no problem. I really dislike the idea of losing the MPG with a stall.

Ragtop 99

iTrader: (7)

A 3000 stall will only cost you 1 or 2 mpg in town (i.e. unlocked) and no loss on the highway. Might even help since it has lower rotating mass. If mpg is your concern, a mild cam and 3000 stall is a better combo than trying to cram a big cam on a stock stall. You'll get better mpg and have good balance between off the line and top end power.

09CPTN

iTrader: (5)

What about something milder, like a 2000-2500 stall, would that be acceptable?

Ragtop 99

iTrader: (7)

Anything less 2600/2800 is a waste. These cars really don't make much power below 3000 and the torque multiplication curve of 2600 stall is very short.

Look in the Automatic Transmission forum. You'll see that a 2800 is pretty much the bottom.