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Performance Modifications


Adrian

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I know that there are lots of you out there who think that Cadillacs are made perfect from the factory and no modification will help increase power. Sorry to break it to you but that isn't how it works. Why do you think there are so many companies that make aftermarket performance parts and so many people who purchase them? They work, that's why.

Why is it that when someone wants to modify a Mustang or Corvette, that's fine with everyone but when someone like myself wants to modify a Cadillac, we are looked down on? I know there are plenty of people on this board who think the same way I do and have experience with making performance mods on their Cadillacs. Why is it I am the only one who will ever say anything about the experience with doing these mods? I am not an idiot and know what I am talking about. I don't dream up these things. I try them out myself before ever saying anything about them. I am sick being contradicted on this board. Even Bruce used to talk about and experiment with mods on his Cadillacs.

I started writing in on this board about 5 years ago. At that time, a large part of the content was about modifications. Now, if anyone says anything about their mods or things they have thought about trying, a few of you have to chime in and tell them it was maxed out for power from the factory and nothing you do is going to make any difference in power.

I have tried different mods on my Cadillacs such as a K&N cone, removal of MAF screen, performance exhausts, chips, and other tricks myself and others have tried. Some worked, some didn't. I learned on my own. No matter what anyone says, I am going to try these things to find the results for myself.

Bottom line....if you don't want to modify your Cadillac, don't.....but leave those of us who want to modify our Cadillacs alone and quit telling us we are crazy for the things we try or have thought about trying. If there is a post about a modification, ignore it and instead, read and reply to the posts about paper air filters, OEM replacement parts, gas mileage, and general repairs.

Sorry for the long post but I am just sick of the certain few people on this board who have to trash anyone who thinks differently than they do.

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I am a big proponent of TESTING mods. Put the car on a dyno before and after, or get a g/tech pro, ap-22, or one of those new g-meters and see what difference the performance mod makes. That's the best way to know whether you have sped up your car or slowed it down.

I have read accounts from mustang or camaro enthusiasts who were sad to find at club meets that their cars with x, y, and z mods were slower than the un-moddified cars. The problem is not that the mods they chose didn't work -- the problem was that they didn't work together or with that level of motor buildup.

The Cadillac performance aftermarket is slim. Put on a performance exhaust, and not much after that. I think it is great if people test more stuff and see what works and what does not. We gain the most through shared information. And it's just fun to test stuff out and see how it does. But it is also valuable to know what the factory guys tested and what their findings were.

Also excellent to have a goal for your car. For the CTS for example, I would like to see it do 0-60 in under 6s on my regular test course. So I need just over a 15 hp improvement on my low time now (6.26s) to do that. Hopefully the Corsa exhaust when it is available might help, and perhaps an intake. I also have a box of intakes parts I tested with the STS and did not find to help performance.

On the other hand, if I wanted it to be much faster, I would have to go to nitrous or supercharging as a power adder, and plan accordingly. As always, it's a question of how fast you want to go, and how much money you want to spend.

You can find numerous performance reports here: http://www.caddyinfo.com/performancereports.htm and mod discussions here http://www.caddyinfo.com/northstarperf.htm

Remember when you test out new stuff and report, there are lots of people rooting for you, hoping it will test faster so they can follow.

Bruce

2016 Cadillac ATS-V gray/black

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So now this board has an editor, that's going to make decisions subjectively, about what we all should read and post?

C'mon Adrian, get real. First of all, I believe it's Bruce's job to moderate this board, not yours. Secondly, and more fundamentally, you need to look up the meaning of forum in the dictionary. This all encompassing method of sharing facts, and opinions and yes, heresay is what keeps us all honest. It's also what hopefully prevents the uninformed from running off with just one source, and making some potentially damaging mistakes. If that happens to be something that upsets you...too bad. Don't read it, or don't respond to it. That's your choice.

'93 STS.. opened, dropped, wide...fast.

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Was going to make this a pm but it sounds like it belongs here --

:o Sometimes it is hard to make everyone happy I guess. I think supporting a healthy aftermarket for performance, appearance, and sound mods is good for Cadillac & the community. There is certainly a lot of money to be spent in it, and people enjoy mod'g their cars, whether to personalize them or find a bit more performance.

But I always want to know what stuff actually does -- preferrably before my money goes into it. So more input from people who have tested works well for me. Engineering insight on what might work, and why, is invaluable to me in planning future tests. I enjoy both sides of the debate on what works and what does not, and don't want anyone to feel muted. But factual test data is the best way to argue.

I wouldn't feel hesitant to plan another intake test just because my last 2 tests showed no gain; I am still hoping I will find a config like Greg did with his Aurora that shows a nice gain, or mods that work well as a whole like Mark did with his 99 STS to get it as quick as it is.

Bruce

2016 Cadillac ATS-V gray/black

Follow me on: Twitter Instagram Youtube

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Why do you think there are so many companies that make aftermarket performance parts and so many people who purchase them?

Because there are people out there who will spend money on it, THAT'S why. You're speaking from personal experience where some mods worked for you. And we're speaking from personal experience where the same mods didn't work for us. That's the very nature of the beast -- you never really know how a certain product is going to turn out on any particular vehicle. Many of us who speak "against" mods aren't at all trying to disuade you from doing anything to your car. It's your car and your money. But this forum is also about trying to keep everything honest, and if someone steps up and says he put on a K&N filter and got 30 horse from it, of course we're going to ask to see the dyno sheet. That would be a GREAT modification...30 hp for 60 bucks! Trouble is, most of us don't see that type of gain, so we're curious, or "skeptical" when someone posts something like that.

Some mods work, and some don't. It's up to you and your money to find out. Regarding intakes, Bruce has a few instrumented tests documented where the performance stayed about the same, or in some cases worsened. When I tried mine, I didn't need a dyno to tell me to take it off. Even if I had more peak horsepower, I still didn't like the way the car drove. That doesn't mean the mod is "bad", it means that I didn't like it. It means that it didn't make power in the various instrumented tests on caddyinfo.com. It doesn't mean that it won't work for you, or that you won't like it even if it doesn't work. If all you're going for is the sound, and any performance gains are just icing on the cake, go for it!

So it's great that some mods have worked for you. Why don't you put together some sort of a profile for your car, to share with the rest of us? Something like "15.1 in the quarter was the baseline, and with xxx brand of exhaust and xxx brand of air filter and with xxx other mods, I got it down to 14.4!" That would be something the rest of us would read with interest. We're all here to learn and share -- not to pigeonhole ourselves to just a few topics of discussion.

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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I just wanted to say that about a year ago I saw the 'Tornado' on TV and actually THOUGHT about purchasing it. I then went on eBay and checked prices.., but before buying, I came here and read what users had to say about it. The reason I like this board is because they didn't just say 'NO' don't buy that crap.., they actually explain to you, [sometimes in words I can't comprehend] why it won't/doesn't work. If your MODS seem to work..., I'm happy for you..., post what you did and what the outcome was..even if it you couldn't measure a HP increase, maybe it gave your car a different sound to it. But, with anything, you're going to have to expect feedback, that's what a forum is!

-Eric

Eric

93 Cad Seville 100K

95 Chev Blazer 143K [garaged summers] :)

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I agree with Bruce. I have been a member of this board for over 2.5 years. Frankly I would not have modified my STS had it not been for all the input I have read from others who have tried different things and reported back their findings. I think it is great to see both sides of the debate. I may not agree with everyone, but use all the data to make my own decisions.

Adrian, I undestand your frustration regarding those that do not believe in modifying but that is their choice or as I have experimented, some mods work for me and others don't. Everybodys car is different and all mods don't work the same for everyone. Some have proven dyno results that the bigger TB showed an improvement, but it was a waste of $350 for me. That is all part of the process of modifying.

I try to "read between the lines" and take it all in.

Like Bruce said, I wouldn't be down to 14.1 in the qtr if it would not have been for this board.

I DO believe in documenting accurately(track times or dyno) to verify what works and what doesn't , not sombody just blowing smoke.

Hang in there!

MARK 99STS

TURBOCHARGED

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I know that there are lots of you out there who think that Cadillacs are made perfect from the factory and no modification will help increase power.

I thought my Brougham was perfect until after the break-in period, and I tried to pass somebody. I installed the air cleaner lid upside-down, but all that did was increase induction noise. I also removed certain exhaust components, but there was still no measurable gain in 0-60 times. Then I increased the engine bore by 0.325 inches, the stroke by 0.865 inches, purchased an Edelbrock camshaft, and added a dual exhaust system. Now I have another problem; quite often, the speedometer needle disappears, and sometimes I have to wait a long time for it to pop back!! :)

___________________________________________________

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I would think nothing of modifying a car from the 60's or even the 70's but I would never touch a car that's being monitored by a computer. Too many things can get screwed up and ruined.

I can buy something from the 60's and mess with it until my heart is content, I don't need to mess up my Cadillac because I want to drive faster in traffic jam ridden New Jersey. In my opinion, the Caddy is fine the way it is.

Just my thoughts..... :blink:

If you really want to make people safe drivers again then simply remove all the safety features from cars. No more seat belts, ABS brakes, traction control, air bags or stability control. No more anything. You'll see how quickly people will slow down and once again learn to drive like "normal" humans.

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  • 1 month later...

just wondering, is it possible for a senser to be bad put not actually fail such as the intake temp senser always reads max temp of the air coming in or the tps never actually sends a wot signal but no codes set and if that were the case A. would you ever know? B. could a aftermarket chip or whatever increase your performance by fixing a problem you didnt know you had....sorry this stuff keeps me awake at night.

Joe <_<

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If a sensor were stuck like that, the computer would realize it. The computer is always reading sensors and performing tests on the system, even as you drive down the road. It's mind-boggling to read through the factory service manuals and see just how much stuff that computer is doing at any one time. If any sensor were bad, the computer would know about it. And if a sensor were replaced with a fixed resistor, the computer would catch it.

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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16 years ago I bought a new Ford Mustang GT Convertible and threw parts at it as they were coming out. Nothing was proven yet and the 5.0L generation was just starting to take shape. I put on JBA shorty headers, off-road exhaust, 2-chamber Flowmaster mufflers on the exhaust side. On the intake side I changed the intake from speed-density to mass-air and added a K&N. Sure sounded like a handfull but track-testing as compared with other 5.0L convertible showed me that I lost about a half-second in the quarter-mile. Live and learn.

Today I drive a Ford Crown Victoria. Watching a similar type of board for that car - I've learned that the K&N Filter I've put in every one of the 15 cars I've ever 'owned' does not belong in this car because of the filter's proximity to the mass air meter. Oil (from the K&N) can get onto the MAF and mess it up. Live and learn.

GF's SLS is bone-stock, save for the rolling stock.

cardio-doc

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Just to add my 2 cents - the intake and exhaust on the Caddy is designed with a large emphasis on being quiet. Consequently they aren't exactly the best they can be for flow and performance. The engine is pretty darn good as is though. I've back-to-back dyno'd (repeatedly) some intake improvements like airbox, K&N, and trottle bodyand found they do help some. I'm sure the exhaust does the most, but a same day back-to-back was not possible. I also dyno'd a granetelli MAF and the thing was a joke (stock one back on).

Anyway, I think some of the misunderstanding may be that one person's "doesn't do much" comment may mean +3 or +5 HP, and to another person, that may be pretty darn cool.

My experience is go ahead with inflow/outflow improvements for a modest gain. The car won't be transformed into something it's not, but will be a little quicker. The computer fake-out stuff is probably a scam though.

BTW - any seat of the pants measurement either supporting or rejecting a mod is ridiculous.

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BTW - any seat of the pants measurement either supporting or rejecting a mod is ridiculous.

I think that's the very basis for those of "us" who said that a single mod didn't make much of a difference. It's not always that simple, though -- there's also a very big subjective factor. I admit that I could feel a seat of the pants difference when I had a K&N cone filter on mine, both positively and negatively. At the upper end, it seemed to pull a little better. At the lower end, it seemed to have less throttle response. Objectively, I was getting worse fuel mileage, so that was an easy decision for me, to put the stock stuff back on. In my particular situation, I weighed the pros and the cons and decided to go with the stock stuff. It felt like I "lost" at least 5-10 hp at the low end, and it felt like I "gained" 5-10 hp at the very upper end. I admitted that I do very little sustained driving above 5000 rpm, so the "gains" would go largely unrealized -- and all I was left with was the worse fuel economy and the poorer throttle response down low.

I think there would be a pretty big benefit in changing the mufflers to low-restriction mufflers. The stock piping is already 2.5", mandrel-bent, stainless steel pipe -- right from the factory (at least on a '97 it is). The mufflers themselves are very quiet, and probably put some restriction on the system. I'm a very big fan of OE parts, but I think that if I ever have to replace either or both of the mufflers, I'm going to put on a pair of Edelbrock RPM series mufflers. My goal isn't more noise, but less restriction. If that comes at the expense of more noise, I think I'll be able to handle it. :)

By the way, I'd love to see some of your dyno graphs documenting your modification performance testing. We've seen instrumented field testing indicating the stock parts work best (open element air filter producing slower 0-60 times, especially during hot weather). Some good dyno charts would really help document what mods work best on what cars.

Thanks,

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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This is my first attempt at hot rodding a Caddy! :blink: I have been a performance car guy all my 50+years. If there are gains to be had with bolt ons I will find them! It's been my experience that all engines like more air flow as long as the PCM can respond. It may require re-programing in order to get the most from any mod. My '67 Impala SS w/LT-1/ 4L60E and 3.08 gears runs 13.70's with no internal mods and no juice. It weighs close to 4000lbs. I don't see why my Seville can't do this too. B)

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Any problems with a cone filter could very likely be due to pulling hot air from the engine compartment. Not sure if it was shielded properly or not.

My dyno graphs are on this web site already. I've always pulled fresh air from behind the fender though. I think that is most imortant.

Yeah - I know, the dyno doesn't prove anything, but the butt does. I did these tests back to back - same day. And I repeated these test on different occasions when I was there to test other small variations like air flow from the side and bottom of box vs. just the bottom.......) If the dyno was giving me +/- 2 and 3 Hp from run to run (same set up) I'd leave and never come back. But the results were spot on repeatable. The only problem is if an early run was with the engine not to full temp and the fluids had a bit more drag on the engine. Those results were not used and could be different.

GM seems to make some of the same "mods" in their improvements. For instance, the Corvette air box has been improved for better flow as well as less restrictive MAF's. The new Northstar TB is 80mm and not 75mm. I highly doubt that the bigger TB is 100% entirely a requirement of the VVT. If it helps the air flow at X cfm for a particular point on the new NS power curve, it's probably a help on the old one as well TO SOME DEGREE. The original 75mm TB mated to a 78mm intermediate piece that's mated to an 80mm intake manifold sure seems kind of a mess. There is nothing smooth about that flow path.

As for a K&N or air box mod, I'd have to agree that paper flows just the same up to a pretty high rpm and it probably flows just as good for most air box designs on a lot of cars. However, if you look at a Chevy 3.1, a 3.8, a Northstar 4.0 or 4.6, they pretty much all have the same sized panel filter. They also have a "horn" or whatever that limits the effectively used area of the filter to a small % of the filter surface. Now, these engines have different displacements and rev to different limits. They have very different breathing needs. It is entirely possible that the pressure drop across one filter at max. rpm is very different than another. Considering that pressure loss is a function of approach velocity squared (the velocity head is V^2/2g), it's easy to see how some cars might be restricted on the top end with a significantly higher approach velocity (squared mind you). If you also consider that any restriction to flow has a corresponding "K" value that is multiplied by the velocity head (think of blowing through a screen door vs. a piece of paper - the screen door might have a "K" or .01 thus creating very little impact to the velocity head while the paper might be 10 or something and 10x(V^2/2g) is a significant pressure loss) it is further easy to see how there can be a difference in some cases. Yes, I've seen the amateur tests of filters where a manometer was employed to measure pressure drop and all I can say is that based on the requirements for such a set up to accurately measure a pressure drop it was not likely done correctly at all and it's for one car only.

Again, I'm not talking about huge gains or losses here. But a few modest gains can be found with some help to the air flow.

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Adrian..

When you post on the net you are hitting a free-wheeling forum. You're going to get opinions, not only on what you did but whether or not you needed to do it. If that troubles you, ask your Mama. She will tell you what you want to hear.

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Jazbo, you're probably right about the cone, that is what my Chevy has, but it is in a position to get decent air. The under hood of my Caddy is much tighter. What kind of airbox mods have you done? I looked at mine the other day but wasn't sure where to start! :blink:

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Ok Kevin, does Pandora's Box mean anything to you?

Nice set of hit though.

It's your car do what you want with it. Just realize that some of the things you do are like nails on a chalk board to some. MC

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