[Mad'lac]

(unless Kevin can convince you I don't know how to use a tape measure )

Remember to take it out of the package first.:histeric:

 

[ssstealth]

Sal,

I know I'm a little late on this one but I have a couple points I would like to throw in.

As others have stated, the intake and exhaust are the first orders of business. The exhaust alone will amaze you. If you really want to open it up, get an exhaust system designed for the 94-96 Impala SS. It will be 6" short in the middle but this will allow you to add an H-pipe crossover to the mix.

In your quest, basically any performance upgrade designed for the Impala will fit on the Fleetwood. The key differences in the drivetrains of these two cars is the 6" wheelbase difference (this is why there is a "B" and "D" body designation) and the 4 channel ABS/TC system.

The next BIG performance upgrade you want to make is the rear end gear. By default, standard Fleets get the 2.56 and Broughams get the 2.93 gear ratio. The trailer package bumps you to 3.42. Check your SPID sticker in the trunk to be sure.

• GM8 = 2.56
• GW9 or GU3 = 2.93
• GU6 = 3.42
• G80 = Limited Slip

My point here is that no performance upgrade that you do to the engine will show its true potential until you solve the rear end problem. I say problem because this is a HEAVY car with lots of torque. My sources at GM have explained that low rear end gear combined with high toque output and the extreme weight of the car have lead to premature transmission failures. Remember that the 4L60E is only rated to handle 350 ft/lbs or torque. The stock LT1 is rated at 335 ft/lbs so you are close to the limit right out of the box. The rear end change will free the car up and let it wind easier. I prefer the 3.42 gears but some have gone up to the 3.73's with success as well.

Finally, you will want to get the PCM re-programmed. Again, the mods you do will not see their full potential until this is fixed. The computer used on these cars is a learning computer. Many mods that you do will be un-done by the computer in its attempt to satisfy the stock program loaded at the factory.

If you wish to do this programming yourself, you will need a computer, communication cable, and some software. The most popular and easy to use is LT1-Edit. This can be found at http://carputing.tripod.com/9495LT1Edit.htm

If you are not ready to tackle this yourself, I would recommend sending your PCM out to be programmed . The most popular in this arena is Bryan Herter at http://www.pcmforless.com

Don't waste your time shopping for chips and hand held programmers for the Caddy. There is a CCM (body) computer on Fleetwoods that is tied in with the main computer that the Impalas and Camaros don't have. This "bonus" has kept the programming options slim. Luckily the Corvette uses this CCM computer also so it is not impossible.

With PCM programming, you will be able to adjust for airflow mods, timing and octane adjustments, as well as tire size, rear end gears, etc. The best thing is that you will be able to dump that pesky 108mph speed limiter. Trust me, you will gain a whole new respect for the Fleetwood when you get it on the open road at 140mph

 

[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.

 

[BeelzeBob]

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?

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?

Next, I re-route the Throttle Body Bypass..

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...

Next is gears.. Upgrade to 3:42.. Where can I get these? Cadillac? Or will any performance shop do?

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?

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?

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?

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?

 

[the Sandman]

Sal

Quick - before it's too late...ban Katshot, toomanytoyz, FleetwoodSS, ssstealth, and anyone else who wants you to molest your Caddy.

You guys are creating a monster...

 

[BeelzeBob]

Haha. Well, I'm extremely limited by budget and technical knowledge.. I'll have to slowly save to get these things done.. I can do some of the stuff myself - and probably will.. But the more important stuff will probably take me until Spring to afford...

 

[toomanytoyz]

That whole "I'm just going to keep it stock" mentality lasted all of a day and a half, huh? lol

Yeah, you sound like you understand everything. If you're going to use a K&N cone filter, then you'd also get rid of your stock airbox. And if you do that, you can just us a straight piece of 3" PVC.

Programming is required for the gear change. Everything else on your list can be done without it. I would recommend Tunercat (www.tunercat.com). It only costs like 20 bucks for the definition file that you need to program for your car, the software is free. It allows you to do all the tuning you'd need to do. That and a 80 dollar cable and a laptop and you're ready to go. The LT1 Edit software Kevin mentioned is great stuff, but it is out of control, pricewise.

The flowmaster cat back comes with an H-pipe. It just allows the exhaust pulses to balance out and it tends to tame the exhaust sound. Supposedly it is supposed to enhamnce the low end torque, but I didn't notice anything. If I were you though, I'd just save the money (500 bucks *or so* installed for a cat back) and go with the summit turbos for now. They're a great, cheap budget mod. And they sound great... You've seen at least one video of my car and heard them...

I went with the 3.73's and wasn't too impressed. I noticed a bit of midrange acceleration improvement, but mileage took a big hit and the highway RPM's were a bit high (IIRC, 2900ish @ 75mph). I'd recommend the 3.42's and an Eaton posi unit. You can get the parts for about 500-600 smackaroos and installation will run you between 200-500, depending upon your "connections." I know of a guy in NY (LI, I think) that will take care of you on the install for about 200 bucks, when you get to that point.

I can't wait to see it in E-town!

 

[BeelzeBob]

Well, I love this car and I'm going to have it for a long, long time.. So, I might as well have it at its best.. I thought I was getting out of the racing-game with this big car, but now I've just got other big cars wanting to play.. I guess it never ends. But I enjoy it...

 

[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.

 

[BeelzeBob]

Thanks.. Very helpful.. It sounds like I should learn to do my own programming though...

 

[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.

 

[BeelzeBob]

Quick question in regards to programming.. If I don't do this after the intake and exhaust mods (the cheap ones), will even these be worthless after a short period of time - due to the automatic learning/re-adjusting?

 

[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!!!!!!!!!!!!!!!

 

[BeelzeBob]

It sounds interesting enough that I want to learn about it - but I don't want to break anything while I'm at it...

 

[BeelzeBob]

Can someone give me a general idea of my Fleetwood Brougham before and after these mods? I'm interested in doing the intake stuff mentioned, the cat-back exhaust (or just the mufflers - not sure yet) and the 3:42s - and of course, the programming...

I'm interested in ball-park horsepower changes, torque changes and 0-60,1/4 mile times...

 

[BeelzeBob]

Bueller? ...Bueller?

 

[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.

 

[toomanytoyz]

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.

Kevin, does your car still have the stock converter, too? You must have a Wednesday car. With intake, exhaust and gears, my car would only run a 15.2! mines probably a Friday afternoon car... Hell, I had to do a cam and rollers in addition to what you did to run my 14.4!

 

[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".

 

[meti]

@ Katshot & toomanytoyz:
I've tried to read the PCM or simply view the engine data. But:
The software says: No PCM found! The connection to the ALDL interface works (ALDL-Test) but the connection between the ALDL interface and the PCM doesn't work.

I know the CCM in the Fleetwood interferes with programming the PCM. What exactly do I have to do to read/write the PCM and get connected.