808ws6

iTrader: (6)

I have a general question regarding large cam'd LS1's.

I have an MS4 cam'd LS1 with a 6 speed.

Is it possible to get the engine tuned so that it can be immediately driven after a cold start without stalling?

I remember 'ol days of pulling the choke which would raise the idle speed and fatten the mixture enough to make the car driveable when cold.

TIA

beardWS6

iTrader: (1)

We are SD tuning mine for better daily driving. With big cams like mine and others its tough. Autos are really tough!

01sscam

My MS4 takes a while to catch an idle in the cold.

12secSS

iTrader: (30)

Depends how cold we are talking about here. Here is So-Cal, I recently helped out a fellow enthusiast with his T-Rex'ed SS, I adjusted a few tables prior to start up. It had not been fired up that day. He started the car and it held idle decently, enough to move it around. That was before any tuning. It can be done.

Lithium

iTrader: (47)

Yeah I am sure its possible cause its all in the tune. I really would not count on it though cause thats a damn big cam.

Patrick G

iTrader: (14)

I've tuned several stock displacement cars with T-Rex cams. While it takes a lot of data logging, it's possible to get them to have very good cold start manners and low rpm drivability. Adjusting the VE tables and running airflow tables are key to making it happen. Without hitting those tables, your open loop fueling will be off and your drivability will suffer.

ibanez7

iTrader: (7)

regardless of a cam or the car. I always let a cold engine warm up before driving

LS1Formulation

iTrader: (13)

Wouldn't it be a smart idea to get a little heat in the valvesprings before driving? Just seems like it would be a good idea with a cam that large.

808ws6

iTrader: (6)

Thanks for all the replies and inputs.

I figured it is the drawback of using a large cam.

It gets to low 60's where I live in the morning.

I knew I was going to get flamed about the driving when cold part, but I am not driving it any faster in engine speed, just moving the car (I live in a association with pain in the *** neighbors).

I'll try some more VE enrichening at cold temps and Desired airflow adjustments.
What table in EFI Live do I specifically change for cold start VE? And what desired airflow is too much for start-up? I am running a 16.2 g/sec airflow at 20 deg c. now.

Thanks!

tilly

iTrader: (5)

how about 20s or 30s? I am just throwing this out there.

c0ncEpT

iTrader: (4)

I have friend with a Stalled MS3 car and on a cold(60) morning he HAS to let it run for a min or to or it will die the second he puts it into gear. but after a min or 2 of it running even if the needle isn't off the bottom it will drive just fine

Patrick G

iTrader: (14)

Regardless of temperature, it's possible to have good cold start manners with the right tune. Nailing the VE tables, Open Loop fueling tables and running airflow tables are the keys. Not something you'll typically get with a mail order tune or a 30 minute dyno tune. Tuners would go out of business charging only $500 for the kind of tune necessary to give these kind of street manners. It takes HOURS of data logging to do it right. If you can find someone who will do it right for $500 or less, pay them the money...otherwise, put those funds to buying your own programmer and have fun perfecting the tune yourself!

yekta

iTrader: (8)

I don't know if my cam is too big but with a good tune now it almost never dies on me unless if the AC is on when I started

SSpdDmon

iTrader: (10)

Is it possible? Yes.

Would I do it? No.

Why not? I don't like valve spring swaps and I'd rather not risk having another spring break on me.

yekta

iTrader: (8)

good call, those are such pain!

beardWS6

iTrader: (1)

Do it right and don`t go cheap. You shouldn`t have this problem!

98Birdie

I have the ls1 hotcam without being tuned and it runs good but cold it surges for about a minute and then idles. But, I have to still feather it ti keep it from stalling with the manual when it is cold. It is a bitch on my sloped driveway.

cowboysfan

I wouldn't do it! drive when it's a cols motor. for one aluminum takes awhile to expand (piston slap) and v-springs are cold. just dont like the sound of this but, it's ur car you do it right (good tune, let it warm up before u stomp on it) should be no problem....................



fuerzaws6

WS6Drop

iTrader: (10)

Mine hunts for a little bit then settles down. I have to hold the gas pedal down a little when I start it to catch idle. My idle tune isnt very good.

marv

iTrader: (40)

With my old setup, it caught an idle just fine...however with the new heads, this time around it wants to hunt around and surge a bit....but only for 20-30 seconds, then it does fine...

Still give it a few minutes to get some heat in the springs though....