[Katshot]

Sal,
The first thing you really need to do is decide what you want to get from the car (a little better throttle response, better 1/4 mile times, etc). There are a lot of modifications available for the LT1 and the rest of your drivetrain in general. A good place to start is the Impala SS home page at: http://w3.one.net/~rcheek/impala/home.html
They list a number of mods that will work on your car, and give a lot of "in-depth" info on them.
I would hesitate to do any "internal" engine mods to the stock LT1 since they are well known to cause bearing failures. If you don't believe me, you can verify this by checking out the last edition of GM High-Tech Performance. There was a small mention of the issue in it.
Just remember that there's very little you can do that doesn't effect something else on the car, so it's very important to plan out your mods properly to make sure that they will work together and no against each other. Modifying cars and/or engines is expensive enough but if you just start throwing mods at it hap-hazardly, it can become a friggin' money-pit and MAY end up not running much better at all.
Plan your mods, spend the money once, get the most bang for the buck.

 

[Katshot]

I can't believe you referenced that article... Of all people who I thought would raise the BS flag on that one, you'd be at the top of my list. That article was a joke. Yeah, some people have noticed bearing failure. Most haven't. People having bearing failure on stock motors too. If you do it right, you've got nothing to worry about. But, that's neither here nor there, as he isn't going that way with his car...

Bill,
Once again, I find myself scratching my head over one of your posts. More times than I can count, you post comments like this one and it makes me wonder what you are basing the statement on.
For a guy that admittedly has virtually no automotive experience, lets his freinds do the mods to his car while he either watches or aids as a "helper", you tend to have rather strong opinions concerning technical topics. Sal started the thread to gather the largest amount of technical info that he could concerning modding the LT1 and not necessarily just to aid him in his personal quest for possible mods for his car. My comment about the article was to point out that doing the mods described in the article to the LT1 DOES IN FACT pose a very real threat to the very life of the engine as described. I think it's rather wreckless to blatently discount an article like this, especially considering the parties involved. I'm sure Jason Cohen of Motorsport Technologies, Inc. would be more than happy to explain his comments to you.
IMO, anyone giving automotive advice should try to be as cautious as possible with other peoples money, especially people with such limited automotive experience.

 

[Katshot]

Sorry Bill but again you are both missing the point AND this last comment ALSO points to your lack of experience.
The first point was that Sal DID NOT state that this thread was to be limited to what mods he is currently considering. If you read his comments since he got his car, he's gone from stating he was NOT going to mod it, to his current statements that seem to be quite the opposite. So I'm not sure even SAL knows what Sal wants right now, so how do you?
The second point was that you HAVE made mention in prior threads that you have little or no automotive mechanical experience/technical know-how. I'm just repeating what YOU have said. If now you say that you DO have experience, sorry I'm not a mind-reader.
The third point was that I was trying to bring a REAL issue to light for anyone that reads this thread, and utilized an article from a respected publication, written by a professional in the automotive field. I believe it to be irresponsible and wreckless to make a blanket statement as you did that the article was BS.
And finally, your statements: "I read that article, and I think it's total BS, only published to make people worry unneccessarily. Yeah, there is always the risk of failure whenever you do a mod, especially a big one like heads and cam, but like I said, if you do it right, and pay attention, you most likely will be fine."
and
"The big reason some LT1's tend to spin bearing after a heads and cam package is because some people go with such a radical set up, and rev the motor to the moon because their new heads and cam will do that, that they go well outside the boundaries of what is safe with the stock shortblock, and stock oiling system."
are totally ridiculous. Please tell me technically what the hell doing a cam and head swap has to do with your engine's safe RPM limit? "....because their new heads and cam will do that......" HUH?
Do you even know what mis-aligned main bearing bores or thermal fatigue are? Those statements just served to prove my point here.

 

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Ah yes, being the leader of the [email protected]#T POLICE is never a POPULAR job.

 

[Katshot]

The B-body LT1 is the same as the D-body LT1.

 

[Katshot]

I have the K&N filter (and the rest of the K&N inlet kit) and love it. Yes, it's more expensive than the Home Depot stuff but it is also a less restrictive inlet system than the Home Depot stuff too (and I think it looks much better too). I would also suggest the 1LE elbow which eliminates the need for a hockey puck or similar object to plug the hole left after the "Home Plate" removal. It is slightly less restrictive than the stopck one.

 

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Yes. B-bodies also include the Buick Roadmasters and the short lived Oldsmobile version, which I forget the name of.

Oldsmobile B-body? You talking about the old 98?

 

[Katshot]

The Custom Cruiser died in '92 and did not have an LT1. It had the 7-code TBI 350 that was in the '93 and older Fleetwood.

 

[Katshot]

Bill is absolutely correct. The gearing change along with the mods to the intake and exhaust really make a BIG difference in both the performance and longevity of the drivetrain. Besides changing the gearing, you should also make sure to install some sort of posi-traction differential. Limited-slip is ok to a point but once you start increasing the engine output and start hammering on the car, limited-slip rears are NOT the ticket. They have clutch packs that you WILL tear up. I would suggest an actual "locking" differential for it's long-term durability. As Bill pointed out, you WILL need to reprogram the PCM after gearing changes. This is not only to correct for speedometer error but also for transmission shift points. If you are into setting up the car just the way YOU want, I'd advise the LT1-Edit application. I use it on my car and it works great. If you'd rather have someone else set it up, Bryan Herter (PCMforless .com) and Ed Wright (Fastchip.com) are probably the two most experienced guy out there. Bill is also correct when he mentioned the PCMs ability to basically compensate for a mod that you do, thereby rendering your mod worthless. And this happens gradually, so immediately, you feel your mod actually worked but over a priod of time, the performance increase goes away. In order to make all modifications actually permanent, you need to change the PCM programming so it doesn't try to compensate the mod away.
Bottom line: if you don't plan your mods properly, you may not actually net the performance increases that you expect.

 

[Katshot]

Okay. Tell me if I've got the right idea here...

First, I'll remove Homeplate and First Base and replace that whole setup with the 1LE Elbow from a Z28 at about $50.00 and piping which connects to the air filter.. All is covered there?
The 1LE elbow only replaces the stock one and takes care of the hole left by the "home plate" removal. Once you remove the "1st Base" you'll need piping to connect the inlet componentry. This why I used the K&N Fuel Injection Performance Improver Kit (using a '95 Impala SS as the application).

Then, I'll remove the entire airbox and replace it with a K&N Cone Filter. Is there a specific model number? And again, is all covered at that point? Or do I need to cutout the stock airbox a certain way?
If you intend to utilize any kind of aftermarket "cone" filter, you'll need to fabricate or buy an air filter isolation chamber. It basically isolates the filter from the hot under-hood temps, and forces the filter to draw cool outside air.

Next, I re-route the Throttle Body Bypass..
It is a popular mod although I've never seen any ACTUAL data supporting it.

Next, I replace the Cat Back Exhaust with one designed to replace the Cat Back Exhaust on a 94-96 Impala SS - and use an H-Pipe (what advantage does this give me) to fill a 6 inch gap...
Personally, I went with a "custom" exhaust but the aftermarket ones are probably just as good.

Next is gears.. Upgrade to 3:42.. Where can I get these? Cadillac? Or will any performance shop do?
Any speed shop can source the parts for you. I use a guy that builds rears, steering gears, column etc. out of a shop in a junkyard.

What happens with the transmission? Being that it's only designed to handle 350ft lbs of torque, am I pretty much killing it at this point? Is there a replacement? Performance rebuild that I need? Or will the new larger gears make this a non-issue?
There ARE build-ups available but to be honest, it's usually best to run it 'til it blows and then get a unit. You COULD get a unit built from a junkyard unit and keep it ready for when yours goes but that's money you don't NEED to spend.

Before I sold my Vette, I went to a pretty good local Corvette repair shop to get things fixed.. Can I have the PCM reprogrammed there? They mostly deal with LT1's... Is getting the computer reprogramming something they'll charge me a lot for?
He SHOULD be able to do it. Usually it's not too expensive but getting it done AFTER gearing or major assembly changes is the usual way it's done. You can count on getting it done several times before you're totally happy though. I don't know anyone that only got theirs done once and was content with it.

And.. Finally.. At what point in my mod-list would I need to get this reprogramming done? I mean - if I'm going to have to do it more than once - and it's expensive - then maybe I'll just wait and do everything at once..

Oh, also.. What do you guys generally think about the K&N Air Filter? Does it let more dirt into the engine?
I like the K&N unit but many people think it's too expensive. My usual opinion is that you get what you pay for. If you're happy with Home Depot piping, go for it. The K&N unit is guaranteed to be superior in both performance and looks but I'm sure the difference is not huge either way.

Thanks for all the help.. This is getting really interesting...

Off this latest topic - what do you guys generally think about Super-Charging the LT1?
If I had the money, I'd have a blower on my car so fast it would make your head spin.

Hope this helps you out.

 

[Katshot]

The only reason I would suggest doing your own programming is so you can setup the car to your taste. The OEM programming is actually fairly good in many ways. The biggest performance gains will be found in the Transmission tables. You can pick up a little in the timing tables if you are careful, and you can definately get a little from the fuel control tables if you utilize a dyno and wide-band O2 sensors. Doing SOTP (seat of the pants) tuning is tough with anything beyond the shift tables.
Unfortunately, doing the programming yourself opens up greater possibilities for screwing things up too, and even potentially damaging the engine or trans.

 

[Katshot]

There is no programming needed for the easy mods like exhaust, cold air intake, etc. The PCM will handle those mods with no problem. Once you know how the system works you'll see what I mean. That's another great thing about using LT1-Edit, you can use the mailing list which is populated by some damn knowledgable guys. Pick their brains, mine, whoever! Once you have the programming capability, you'll need to understand how the various systems work so you understand what effect the changes you make will have on the car's performance, fuel economy, emissions, etc.
If you don't want to get into it that far, get someone else to do the programming.
The one thing you'll learn (if you decide to really get into the programming) is that many popular mods are REALLY worthless and there are a lot of things you CAN do that can make BIG differences. You'll find that the guys that just buy parts based on other peoples suggestions, but don't REALLY understand the engines or the management systems, are really wasting a lot of money!
There's a lot more idiots out there that THINK they know what they're doing than you might think.
I've only found a few guys that are TRUELY worth listening to. The rest TALK a good game but really have NO CLUE! For instance, there was this one guy over at the Impala SS forum that used to get a lot of grief from some guys but I thought the guy was just this side of BRILLIANT! He had an Impala SS in the 13's with only "bolt-ons" and no slicks. As he always said (and I agree) how you "setup" the car is more important than ANYTHING! You'd be surprised how many cars I've beat at the track just because of setup. Cars that SHOULD have waxed my ass if you were just comparing mods and specs. That's why I always say "any car, on any day". Preparation is EVERYTHING!!!!!!!!!!!!!!!

 

[Katshot]

It really depends Sal. Some guys seem to get much better results than others. I assume it's do to WHO actually is doing the work, and WHAT specific parts are used. My car seemed to respond very well to the intake and exhaust mods. Hell, I haven't done much else besides those and the gears. My 14.5 is totally just the product of INTAKE, EXHAUST, GEARS, and PROGRAMMING. Hell, I haven't even done a tune-up to the car since I've owned it.

 

[Katshot]

All I did was a "cat-back" custom exhaust with 2.5" pipes and 3-chamber FlowMasters. Oh yeah, don't forget the Auto Zone chrome tips too! They're good for 20 extra HP I hear.
It's like I said, some guys get a lot better increases form the same "TYPE" of mods. The reason I highlight that is because there are SO MANY different CAI setups, air filters, etc. available, and just doing an exhaust system doesn't mean it's same thing. All components are NOT created equal, and then you have the installation issue too. I've seen some actual mechanics do tune-ups and actual net a DECREASE in MPG and performance. All mechanics are NOT created equal either.
It's just like I've always said, it's all in the "setup".

 

[Katshot]

Pull the CCM fuse and you're in. :thumbsup: