I installed a new cam and springs in my car and need to do some tuning with LT-1 edit. I have the program already but haven't had alot of experience with it. The specs on my cam are 248 and 252 @50 546 lift and 114 lobe seperation. Does anyone know what I need to do to the tables the car really likes rpm right now and bogs alot down low its too rich down low. Once I get it up over about 2000 it runs fine. So any body that could help me out I would really appreciate it.

 

That cam, even with it's 114 LSA, is probably pretty inefficient down low and will make the car seem like a dog for everyday driving, but if you are in closed loop, you are going to run at 14.7 afr as long as the O2 sensors and MAF are working and you don't have any mechanical/electrical problems that would make the computer go out of it's adjustment range (ie. intake/exhaust leaks, leaky injectors, bad O2 or temp sensors). You could try changing the timing down low and see what that buys you, but you need to scan and log it as you are driving around and see if it's healthy first. If your fuel trims are way off, I'd troubleshoot that first, then see how it runs. You can't really change AFR in closed loop unless you make a device to offset the O2 sensor voltage that the computer sees. Now, if you're open loop, then that's a different story.

BTW, if that cam runs crummy down low and likes to rev, then that's pretty much what it is designed to do. You don't stick a cam that's meant to work at 3500-7000 rpm and complain that it runs crappy at 2000 rpm.

You also need to post more detailed info about your setup (compression, head work, etc) to get a more helpful answer. Since you're in OK, you might want to go get an Ed Wright dyno tune. He has a good rep for tuning LT1 cars and will optimize your part throttle.

 

The first thing you have to do is datalog it to find out what it is doing.

 

Ok well my specs are all stock except for the cam. I know its going to run better up top and thats what its meant to do but down low its real bad it has a random miss that comes and goes down low. I know itll be a little sluggish bit this is bad. Remember I'm new to this LT1 Edit thing so how do I data log while I'm driving to get the info.

 

All stock as in not even headers ? Read Kevin's post again. Tuning is not going to magically make a cam that huge in a stock car have low rpm torque. Some really steep gears will help. To datalog OBD2 LT1s, you will need a program and cable like Autotap. I use that and my HP Tuners scanner to log OBD2 LT1s. There may be others I'm not familiar with, but your LT1edit package is only a programmer, not a scanner. Where in Okla are you?

 

I have headers 3 inch exh. no cats, the cam listed above with new springs, cold air induction the screen on my MAF is removed no head work no compression change no intake work. Hven't done a whole lot of engine work just a little bit that I could afford to give the car some kick. I know lt1 edit isn't going to work miracles but with this new cam the car runs rough and needs a little fine tuning to smooth things out. I just need a little help to know kind of where to start if anybody has any ideas. If i cant run a data log with lt1 edit how would i go about doing that? I was in stillwater ok I haven't updated my stuf lately I've been gone a while I just got out of basic training for the air force and am currently in Wichita Falls Tx for my tech school.

 

IMHO You are way over cammed. A smaller cam would be a lot better for you, a lot more fun, would run a lot better, and maybe retain some mileage. It is one of the most common mistakes a guy can make - a lot of others before you did the same thing. The cam companies always say to look at the rpms the car runs in 95% of the time and pick one that at least works in that range. You want a big duration cam, heads have to be worked and the valve train has to be beefed up, and then it needs to be used in it's intended purpose.

When I was a kid, the thing was to put on a big tunnel ram with dual 4 barrel carbs on an otherwise stock Mustang or Nova with headers, and those cars never ran right either. Thank God gas was cheap then.

 

And if you do not know enough about tuning or using your Edit software, your best bet will probably be to contact a mail order tuner, send them your file, and have them try and make it more driveable. I also agree that you are way over cammed. That cam with your 3.42 gears is a big mis-match.

 

One of the biggest impacts I've found with my cam is increasing timing advance. Especially in the higher kpa areas where the engine idles (~60kpa for my 239/248 .577/.600 114LSA).

It's been a night and day difference for me. I'm talking big changes, like 10-15* in the upper kpas in the lower RPMs (800-1600), 5-10* in the lower kpa for the same RPMs, and 2-5* in the higher RPM/kpa (2600+).

 

Ok I have more time today to explain it all a little better. With me still in tech school in the airforce my time is a little crunched right now. I know I'm way over cammed but while I was at basic I left the car with my friends at a custom shop I work at for them to paint the bumpers and buff the car to get it looking better. When I came back the car now has a two tone paint job with flames to separate the two colors, header and a y pipe, cold air, new 18" black wheels and tires, cam, and been lowered about 2". They talked to some people and heard this cam would work good for now but be great for the plans I have later which include 4.10s, a procharger and of course head and intake work. They were being some very good friends and helping me get a good start I know the setup isn't perfect I was just hoping for some help and I appreciate all the replies. I'm going to try it myself first with the knowledge I have I think I'll get it but thanks for the input on mail order stuff I hadn't though of that if I do that who do I contact and about what does that run. Thanks again for all the replies.

 

Call or e-mail Ed Wright

E-mail - fastchip2@sbcglobal.net
Postal - 1114 West 41st St, Tulsa OK 74107
Phone - 918-446-3019
Fax - 918-446-1233