i just put in a lt4 cam and intake stuff...i seem to have lost a lot of low end power and the car doesnt seem to run very well...i know im in need of tuning since i have the stock computer but would this account for these problems? or what else should i look into/try?...could it just be a timing issue? and in reverse when the car is hot (and rarely in drive) it was stumble and stall...think this has anything to do with it? thanks guys

 

I'm assuming you're talking about the LT4 Hotcam correct? It's more aggressive than the regular LT4 cam.

Yes, it would have that effect. I noticed a loss of low-end with the ZZ4 cam, and it's nowhere near as "hot" of a cam. The hotcam is intended to make power quite a bit higher, but will sacrifice low-end. Although some people may argue this, it's not really ideal for a long-tube runner set-up.

You may also need to consider new gears if you have a 2.73:1.

...and yes, you WILL NEED A CHIP. No doubt about it. I wouldn't expect the car to run well without it.

 

I just noticed you have a 305. That cam might be too big. I'm not really sure.

Anyone else have a comment on that one?

 

yeah if its a hot cam, your gonna need to chip it cuz that cam is huge. too big for tpi on 305. IF on 350 it would be alright but not ideal.

 

I have a well tuned 355 with the HOT cam and yes, you need to tune it. It took me a little bit of messing. With low gears and a (gulp) 305 you will deffinatly need a chip as it will bog until maybe as high as 2,000 RPM. I love Mega Squirt by the way.

 

yeah its not the hot cam its the rgular one...specs are .446/.450 203/210

 

I do not think it would be bad above 1500 RPM then. Many others with 305s favor the ZZ4 and LPE cams. It looks to me like an OK choice.

 

so u think with tuning it will be ship shape? right now i floor it fro m sto pand the tires dont even spin...will gears striaghten this out then?

 

Gears will help as far as the feel goes, but that's just treating the symptom. To cure the problem, you need to tune the fuel injection....and that means burning chips (or finding someone to do it for you, preferably NOT through the mail.)

 

That's exactly right.

You're in the same (similar) boat that I'm in. I just installed the ZZ4 cam and SLP header/Loudmouth on my L98. I currently have my stock 2.73 gears and although the top end is noticeable better, the low end is noticeably sluggish. No tune in the world is gonna make up for my planned 3.73 gears, but without a tune I'm still giving up TONS of power. Why do all that work just to half *** it on the tuning end, and that's assuming it's even running well. Since my car runs pretty good on the new cam, and the newfound power ate my 700r4, a tune is still a month or two away, but it's on the short list!

 

...and some more food for thought...

Although I do NOT recommend a mailorder chip, Ed wright at fastchips may verywell be the best mailorder chip. A few months back, GM High Tech used one of his chips on there project BT 305 TPI after a cam swap, and it took several chips to finally get it right. They commented in the article that so few people get very deep into the 305, they didn't have a lot of experience, and it took a few tries to get it right.

That may say a lot for Fastchips and there customer service, but It just goes to show that even someone who knows there stuff really needs to have the car present to burn an effective chip.

You're best bet is to find out what shops are tuning LS1 and LT1 cars. A good bet would be that they also tune Gen1 SBC EFI too.

There's a top notch EFI tuner here in NC that charges $400 for a dyno,tune, and re-dyno, on a N/A TPI motor. Heck, a Hypertech almost costs that much!