Will I need to get LT4 knock module or do I already have one...since mine is a 96? Someone told me I have one already in a 96.

 

Hold off on it. It's not a big deal 'cause the cost is cheap, but after my LT4/Hotcam swap I didn't notice any extra timing retard while using the LT1 version. Do some data logging first and see where you're at.

Even though I had no trouble with my LT1 module, I slapped in the LT4 module since I had it (bought before the rebuild). Just couldn't stand to see it sitting on the bench.

 

Did you notice a big difference in your cars performance after cam? Also I take it that the 96's didnt come with the knock module?

 

Well, it's tough to quantify the performance. I did the LT4 heads, intake (plus a few non-performance, durability enhancements) and the Hotcam. I also tossed in an Edge Racing 2800 stall converter.

So far I've kept the shift points to about 6K rpm so I'm missing out on a few hundred rpm worth of performance. But the cold weather has allowed for zero traction through first gear (2.59's out back) and will hook up after a half second into second gear. That about sums up the low end.

I can say that the pull from 80-140 is quite a bit stronger than previously. And that's the area I'm really concerned with. The cam really doesn't seem to hit until after 3000rpm. The pull gets much better when you swing past 5k.

Mid April I'll be hitting the dyno with a few other Forum members and we'll get some real world numbers. I'll try to twist it up to 6500 for those pulls.

Through the stock exhaust, I'm expecting around 320-330rwhp at best. And this will only be with some optimum tuning. Since I'm trying to keep it emissions legal (for the time being) I'd be pretty happy with that.

Overall, the car does feel great at low speed/large throttle angle, but I'd have to contribute a lot of that to the converter. The 80-140 is hard to deny though. It does pull well through that range. And I've made a lot of runs at those speeds with the previous (100K) engine which made a few runs to 160mph +.

I'm guessing that the swap to LT4 heads, intake and the Hotcam are probably worth about 50-60hp at best (through stock exhaust). But I'll report back in mid-April.


[Modified by Dan Parker '96, 5:35 PM 2/26/2003]

 

Cool, did you change the Timing chain. I Wont but I heard it wont really matter that much till you stay above the 6000rpm range alot?

 

Having just done the Hot Cam installation, I found the original timing chain in my LT4 very loose (65K miles). I replaced it with the extreme duty chain during the installation. A tip that you may already know is to cut open a small container, such as oil jug, and put a few ounces of kerosene in it. Drape the new chain over the sprocket and dip into the container. Rotate the sprocket to thoroughly was the chain off and then put in new oil. Rotate the chain in the oil to get it nice and soaked before installation. I have found this works really well on a new installation to make sure it is clean and well lubed upon start up.

 

Unless I'm mistaken, isn't a replacement timing chain set for the LT4 about $350?! Why on earth is it so darn expensive?

 

extreme duty set, GM #12370835, is net $222.35 from Jeff Kopp at Superior. It does have just a hint of a whine but not objectionably loud by any standard. After seeing how loose the original was, I do have peace of mind knowing that it is there probably for the life of the engine. But then, whenever I have to R/R a mechanical piece, I like to make it better than before if I have to do the job. :)

 

Thanks for the part #!