LT4 Hot Cam Kit Questions

[markd79ta]

Enough ing in my Beer, I need to finish the '97 so that I relearn to love this car as I did when I got it. I purchased the loudmouth and it is on its way...finally. I am looking at some Edelbrock or Mac headers with y-pipe. I am thinking about pulling the heads and porting them along with dropping in the LT4 Hot Cam Kit.

Has anyone done this? Will the stock PCM deal with the cam OK if I use the LT4 KM, or do I need to ship the PCM off for a new program?

[95TransAm]

I'm not the expert so I'm sure you will get a more detailed better answer....but I can go based on things I have heard.

I've talked to people who dropped in a hot cam with out retuning their PCM and apparently they haven't had problems. Then again, this isn't first hand experience of me physically seeing their car, it's just what I've been told.

With head work though, I'm not too sure so I won't even attempt to reply on that one. I know if it were me personally, I would most definitely send my PCM out and get everything tuned perfectly. Might as well do everything right the first time, and squeeze out all the potential that your motor has at the same time. By the end of this summer, I am most definitely getting rid of my programmer and having my PCM tuned properly. Only reason why I got this in the first place was because I had a good deal on it.

Also, you are aware that the hot cam is a pretty mild cam. I'm not sure exactly what your goals are, but with head work, I would imagine you would probably want a little more aggressive/streetable cam. Also would recommend at the same time gettin some new RR's, valve springs, and pushrods to compliment the whole set up nicely.

Good luck with the build up and keep us posted

[markd79ta]

I'm not the expert so I'm sure you will get a more detailed better answer....but I can go based on things I have heard.

I've talked to people who dropped in a hot cam with out retuning their PCM and apparently they haven't had problems. Then again, this isn't first hand experience of me physically seeing their car, it's just what I've been told.

With head work though, I'm not too sure so I won't even attempt to reply on that one. I know if it were me personally, I would most definitely send my PCM out and get everything tuned perfectly. Might as well do everything right the first time, and squeeze out all the potential that your motor has at the same time. By the end of this summer, I am most definitely getting rid of my programmer and having my PCM tuned properly. Only reason why I got this in the first place was because I had a good deal on it.

Also, you are aware that the hot cam is a pretty mild cam. I'm not sure exactly what your goals are, but with head work, I would imagine you would probably want a little more aggressive/streetable cam. Also would recommend at the same time gettin some new RR's, valve springs, and pushrods to compliment the whole set up nicely.

Good luck with the build up and keep us posted

The nice thing about the LT4 Hot Cam kit is that it gives you the 1.6 GM Roller Rockers, the cam, and the new valve springs for $525. I may need to get new lifers and I definitely need a new timing chain, but that is all I will need. I am pretty experienced with a mild clean up and match port job so that is free...just lots of time. I have other priorities so I can only afford the Hot Cam kit, my headers, the loudmouth, and the simms for the back O2s. If I decide to keep the car, I will do a full build-up for a supercharger and put a ATI Procharger later on after my house renovation project is done. I think it will depend on whether I decide to sell this car or not, but it needs help in the short term.

[95TransAm]

Ah, I gotcha now Ya know, I knew all that came in the kit, I just wasn't thinking before. For $525, and being on a bit of a budget, that's a nice little setup that they give you. I also agree on the timing chain....didn't even think of it before but strongly recommend it as well. Lifters are a possibility. If funds allowed...why not would be my take on that. It's just that when I finally tear into my engine, I want to do everything all at once. If you think that in the future, you will be tearing in to it again, I'm sure you could get by without having to get new lifters or pushrods.

In final response to your original question though, I would defintiely send out your PCM to get tuned. I say that mainly because of your head work. I'm sure you could get by, but if you're tearing in to things that much, you might as well get optimum performance with a good tune up

[markd79ta]

Ah, I gotcha now Ya know, I knew all that came in the kit, I just wasn't thinking before. For $525, and being on a bit of a budget, that's a nice little setup that they give you. I also agree on the timing chain....didn't even think of it before but strongly recommend it as well. Lifters are a possibility. If funds allowed...why not would be my take on that. It's just that when I finally tear into my engine, I want to do everything all at once. If you think that in the future, you will be tearing in to it again, I'm sure you could get by without having to get new lifters or pushrods.

In final response to your original question though, I would defintiely send out your PCM to get tuned. I say that mainly because of your head work. I'm sure you could get by, but if you're tearing in to things that much, you might as well get optimum performance with a good tune up

Yep, if I sell the car, this would be a nice setup with the 4.10s. If I keep it, I will enjoy it until I can pull the motor and put some money into it. I want a forged rotating assembly with 9.5 pistons so I can run a higher boost level, and I can't do this until I can put a 12 bolt in the back. My other priorities won't allow me to spend this kind of money until my house is done.

I know that I would benefit greatly with a program, but my question is more along the line of will the PCM throw codes with the cam? If it does, then I will need to wait a little longer so I can do the Hot Cam Kit and the PCM at the same time. I would like to pull apart the motor this fall and start the port job.

[95TransAm]

I couldn't imagine that your PCM would be throwing codes. As long as everything is done right, it really shouldn't. Once again I'm stating this not on first hand experience, but what I've come across over the years.

Anyways, a PCM programming would only cost a couple hundered...not too much. When you can, I suggest it

[Z Ya Later]

No, I believe you will need to reprogram your PCM. I'm not sure about throwing any codes, but the car will not run right on the stock tune. It will be expecting the stock cam profile and not the LT4 Hot Cam. Either a local dyno tune or a mail-order tune would fix this, plus give you some more horsepower. As for the headers, are you looking at shorties or long-tubes? Mid-lengths perhaps?

[markd79ta]

As for the headers, are you looking at shorties or long-tubes? Mid-lengths perhaps?

The Edelbrock '94-5 set with y-pipe. I think they are short to mid length.

[jerrysta]

I'm no expert either, but in researching headers I believe the Edelbrock headers are 1 5/8 primaries.....and I think that is going to significantly choke a motor that has head work done.

I am planning on headers as well and RK sport sells a clone of the AS&M's (thank Fred, BTW ) for 450, with the ceramic coating. These have the 1 3/4 primaries. The set-up includes the y-pipe too.

Again, I'm no expert, just regurgitating what I have read here on the site from the real experts.

[pete]

I've done the Lt-4 cam setup, but haven't done the program yet (been a year). Runs fine, but feels like it would do more with the proper program. Just been for funds and time to do the headers, exhaust, and gears.

[Rob]

It will throw a random misfire code. My 96 WS6 did all the time. It also ran incredibly lean. Back then nobody knew how to do OBDII flashes, so I ended up running a 95 PCM with new programming. Since then, reprogramming is easy and you can get rid of the codes. The knock module only works if you have false knock.

Other than that, I ran completely emission legal on mine. SLP dual cat headers into the stock y-pipe into a Borla/SLP cat back. Still ran stock heads though. It ran 12.4@111 on Nittos. More could be had with long tubes, no cats, etc. But mine easily passed the IM240 treadmill. Probably wouldn't pass now if I had to throw in the original computer since they use the ALDL port to test now.

Hope that helps.

[markd79ta]

I'm no expert either, but in researching headers I believe the Edelbrock headers are 1 5/8 primaries.....and I think that is going to significantly choke a motor that has head work done.

I am planning on headers as well and RK sport sells a clone of the AS&M's (thank Fred, BTW ) for 450, with the ceramic coating. These have the 1 3/4 primaries. The set-up includes the y-pipe too.

Again, I'm no expert, just regurgitating what I have read here on the site from the real experts.

This isn't my dream setup, I am getting the headers, y-pipe, and cat used. Since my current cats are plugged with carbon, this should work fairly well. When/if I do my build-up later on, I will use long tubes.

[markd79ta]

It will throw a random misfire code. My 96 WS6 did all the time. It also ran incredibly lean. Back then nobody knew how to do OBDII flashes, so I ended up running a 95 PCM with new programming. Since then, reprogramming is easy and you can get rid of the codes. The knock module only works if you have false knock.

Other than that, I ran completely emission legal on mine. SLP dual cat headers into the stock y-pipe into a Borla/SLP cat back. Still ran stock heads though. It ran 12.4@111 on Nittos. More could be had with long tubes, no cats, etc. But mine easily passed the IM240 treadmill. Probably wouldn't pass now if I had to throw in the original computer since they use the ALDL port to test now.

Hope that helps.

Yes, that helps. It looks like I will need to get it tuned. I will put the PCMforless charge in my budget.

Actually, from what I understand, the after-cat O2s can be programmed out of the PCM. If this is correct, I can use the money for the simms to pay for the program.