L99 owners with slow cars going to dealers for fix.

[PQ]

Originally Posted by BackinBlackSS/RS

15lbs a wheel and 21 inch wheels is going to have more impact on performance than you think. Probably not the full second, but certainly you will not be getting the advertised times from GM. Having said that, I still believe the problem is in the PCM/TCM tuning.

I just can't see any more than maybe .1 sec. to 60 as far as straight line acceleration when we're talking about a 13 or 14 second car. Get to the 10s and 11 second cars and maybe you lose a half a second but we're not gonna run those times with stock Camaros.

[slowerthanu]

What is clear is that not one single person on this forum (so far) knows what the hell is going on. Some of us have good suggestions and others pull ideas out of thin air.

What it is going to take is all of the owners that feel their vehicles are underpowered, need to get out to their respective dealers and make an official report with GM QC. Until then we will all be left either guessing or voiding our warranties

[speedster]

Originally Posted by patriotpa

...so what would be the best combination of tire/wheel to get the lowest rotating mass while keeping the OD and width of the tire the same? Titanium is light as hell.

Just something to think about - Top Fuel, Funny Car and Pro Stock all use 16" rims. They do that because of rotating mass/inertia issues. Most drag racers use 15" rims for the same reason. Plus these combos allow for correct sidewall flex.

[PQ]

Originally Posted by slowerthanu

What is clear is that not one single person on this forum (so far) knows what the hell is going on. Some of us have good suggestions and others pull ideas out of thin air.

What it is going to take is all of the owners that feel their vehicles are underpowered, need to get out to their respective dealers and make an official report with GM QC. Until then we will all be left either guessing or voiding our warranties

I am so efing busy during the days I can't even describe. My business requires that I be here so It's hard but I think I'm on to something.

Originally Posted by speedster

Just something to think about - Top Fuel, Funny Car and Pro Stock all use 16" rims. They do that because of rotating mass/inertia issues. Most drag racers use 15" rims for the same reason. Plus these combos allow for correct sidewall flex.

Soooooo then why don't they use titanium rims? If it's circular mass slowing them down and the weight is multiplied then it would seem the wheels would become the most important part of the car where weight is concerned. Those dragsters and other high speed racers need their rubber to expand. I am a racing idiot. I don't know?

[SGOS252382]

We know the V6 Camaro dynoed 246 rwhp, so if Scott's SS got beat by a
V6 Camaro, I can only imagine how much rwhp its putting down?

That's why I would love to see some dyno numbers from some of these
"slow" L99s.
Someone needs to bite the bullit and get their car on a dyno.


It seems that most of the "normal" L99s are coming in around 320 rwhp.

[MTron]

Originally Posted by irpq11

I just can't see any more than maybe .1 sec. to 60 as far as straight line acceleration when we're talking about a 13 or 14 second car. Get to the 10s and 11 second cars and maybe you lose a half a second but we're not gonna run those times with stock Camaros.

Originally Posted by BackinBlackSS/RS

15lbs a wheel and 21 inch wheels is going to have more impact on performance than you think. Probably not the full second, but certainly you will not be getting the advertised times from GM. Having said that, I still believe the problem is in the PCM/TCM tuning.

You should swap PCMs with another L99 to see if the issue gets better

[pharmd]

Originally Posted by leviticus88

I agree about trap speeds but Just make sure comparing the same "types" of vehicles. Such as rwd v8 (auto or manual) and similar weights. My 230whp fwd traps 101 with a 14.5 quarter. It doesn't have 300hp at all. lol But it weighs 2800 pounds.

Get my drift? Only compare cars that are close to the same weight and have the smae types of motors and drivetrains.

That's why I used my 4 door BMW for comparison, not crazy weight difference, same weather, both rwd, both auto etc. ;-)

[SGOS252382]

Originally Posted by pharmd

That's why I used my 4 door BMW for comparison, not crazy weight difference, same weather, both rwd, both auto etc. ;-)

I ran 13.3 @ 100 mph with 225 awhp in my 02 WRX. With 300 awhp, it ran 12.7 @ 108 mph. You definately need to compare apples to apples (similar weight and setup).

[Restroom]

Originally Posted by speedster

Just something to think about - Top Fuel, Funny Car and Pro Stock all use 16" rims.

Yeah, and those jokers are using (gasp) automatic transmissions too! The nerve! Why, if they ever showed their faces around this forum, we'd teach them a thing or two!

And whoever was talking about titanium wheels, let me know how those price out for you.

[Dans ls1]

So whats the word on this? Seems like lots of complaints with the auto. Curious what the dealer says...

[PQ]

Originally Posted by SGOS252382

We know the V6 Camaro dynoed 246 rwhp, so if Scott's SS got beat by a
V6 Camaro, I can only imagine how much rwhp its putting down?

That's why I would love to see some dyno numbers from some of these
"slow" L99s.
Someone needs to bite the bullit and get their car on a dyno.


It seems that most of the "normal" L99s are coming in around 320 rwhp.

I may be the one. Gotta check a few things out first.

Originally Posted by Restroom

Yeah, and those jokers are using (gasp) automatic transmissions too! The nerve! Why, if they ever showed their faces around this forum, we'd teach them a thing or two!

And whoever was talking about titanium wheels, let me know how those price out for you.

That would be ME. And I asked the question along with a disclaimer that I'm a racing idiot and I don't know. I understand that the cost would be astounding but I also understand that some of these racing teams spend millions. Surely it's not a foul to ask a question on a car forum?

[69 Hugger]

Originally Posted by PatrickfromMD

My L99 feels like it was tuned by the Cadalic division
During the Q&A session at Carlisle, I praised the GM team for a job well done , and mentioning some of the things I really liked about the car, but then opened up into a question about my poor dyno run for my L99, and if I was seeing expected numbers or something outside the expected parameters. . Al came back and asked me what the numbers were (I did not initially mention the specifics as I did not want to seem bashing to an otherwise fine car in a public session) . I told them it was a conservative dyno (Superflow) but it only made 305 WRHP on its best pull. http://http://www.camaro5.com/forums/showpost.php?p=613731&postcount=14
They did not have a lot of suggestions, and I did not want to back them into a corner, so I just praised the car and moved on. At least they were all there to hear my concern (Scott Settlemire, Cheryl Pilcher, John Fitzpatrick, Al Oppenheiser and John Cox ) as well as hundreds of others. Later (after the public session) I showed AL my dyno sheet. I mentioned that my dyno operator had run a LS3 car a few days before mine and had said the timing curve on the L99 was more conservative than the LS3. Al appeared to concur that the setting were less aggressive on the L99.
Al did say that he attends a teleconference each week with the dealers where issues are brought up that seem to be occurring regularly. He suggested I have my dealer look at it, and that if they have concerns that they bring it up during the call. (He also suggested I run in sport mode more, and although it des not seem to help in Engine performance, transmission shifting is somewhat better)
I plan to take the car to the dealer and mention they look at this avenue.
Scott what was your dealer specifically going to try and do?
I spoke to Al a bit about the limitations of the DOD, but there was a lot going on around us and we did not have the time to get into detail about it. I did get the impression that some of the tuning is there to help with the reliability of the AFM (DOD). I wish I had had a chance to explore that subject in greater detail, as well as Torque Management. Al said there is always the chance of updates to the computer tune, and that the performance parts group would likely offer performance tunes (I hope to hear more about that).
I hope to get mine to the track with 2 other guys (another L99, and an LS3). And hopefully run them all together and have some more data to compare.

The pic is with Al and myself... real smart guy!. (note rolled up dyno print outs in my hand). BTW - He brought his teenage son, boy, thats one lucky kid.

Figured the low HP numbers from the L99 had reached GM/Factory reps, hope you guys get them figured out soon, keep us updated

[uke]

Hey guys, I got referred to this thread from another car forum.

A few things pop into mind when looking at this:

1. What kind of gas are you using? I didn't see it brought up, but you ARE using premium fuel in this car, right? Anything less than premium *will* have a significant impact on performance.

If you are using premium, what BRAND of gas are you using? Have you tried switching to different brands in diagnosing the issue? I know that many LS2's have been finicky in what gas they're using, especially in fuels with the 10% ethanol blend in it. It's been known to cause some knock retard (KR), which can affect performance (more on that later). Have you tried switching brands? I know around me, Shell and QT have 10% ethanol blend gas, so I've shyed away from them.

2. Your wider, heaver wheels are affecting performance more than you think. I don't care what your friend in the 350Z "felt", but the laws of physics do not lie.

Here's an experiment you can try. Stand in the middle of a room, with your arms tucked into your body, and spin around as fast as you can.

- Now do the same thing with your arms outstretched.

- Now do it again with 5 lb dumbells in each hand.

What happened? It got harder to spin around each time, right? The EXACT same principle applies to your car's wheels. When you make the wheel wider and heavier, the engine has to work that much harder to get that wheel spinning. And I guarantee that the difference is probably a good bit more than you think.

Larger, heavier wheels will ALWAYS negatively affect performance. It is not possible to circumvent this principle. You can't have your "bling" and your "zing" as well.

3. Is there anyone in your area who can hook up a Predator or other car scanning tool up to your car and see what the engine is doing. Chances are, you are getting knock retard (KR) from something, which means less power.

For those not in the know, Knock Retard is where your car's onboard computer detects conditions that are favorable to knock (i.e. pre-detonation), and pulls timing from the engine in order to prevent knock from occurring.

Note: you cannot HEAR knock retard, so "I can't hear my engine pinging, so it must be fine" is not a valid argument. Only way to see if you have KR is to hook up an onboard scanner and do some WOT pulls.

Anyway, when the car's computer pulls timing in the form of KR, that loss of timing = a loss of power.

Several things can cause KR in a stock car, the biggest culprit being bad gas (from point 1). Also, hot weather can cause more KR than cold weather. What were the outside conditions when you performed these tests?

4. Has anyone yet hooked up an HP Tuners suite to these cars to see how restrictive the Torque Management is on these vehicles? Not much I can say on that unless someone's actually done the work to see if TM is holding the auto's back. If TM is an issue, a simple retune could fix that.

Anyway, hope this helps in figuring out what the issue may be.

[PQ]

Originally Posted by uke

Hey guys, I got referred to this thread from another car forum.

A few things pop into mind when looking at this:

1. What kind of gas are you using? I didn't see it brought up, but you ARE using premium fuel in this car, right? Anything less than premium *will* have a significant impact on performance.

If you are using premium, what BRAND of gas are you using? Have you tried switching to different brands in diagnosing the issue? I know that many LS2's have been finicky in what gas they're using, especially in fuels with the 10% ethanol blend in it. It's been known to cause some knock retard (KR), which can affect performance (more on that later). Have you tried switching brands? I know around me, Shell and QT have 10% ethanol blend gas, so I've shyed away from them.

2. Your wider, heaver wheels are affecting performance more than you think. I don't care what your friend in the 350Z "felt", but the laws of physics do not lie.

Here's an experiment you can try. Stand in the middle of a room, with your arms tucked into your body, and spin around as fast as you can.

- Now do the same thing with your arms outstretched.

- Now do it again with 5 lb dumbells in each hand.

What happened? It got harder to spin around each time, right? The EXACT same principle applies to your car's wheels. When you make the wheel wider and heavier, the engine has to work that much harder to get that wheel spinning. And I guarantee that the difference is probably a good bit more than you think.

Larger, heavier wheels will ALWAYS negatively affect performance. It is not possible to circumvent this principle. You can't have your "bling" and your "zing" as well.

3. Is there anyone in your area who can hook up a Predator or other car scanning tool up to your car and see what the engine is doing. Chances are, you are getting knock retard (KR) from something, which means less power.

For those not in the know, Knock Retard is where your car's onboard computer detects conditions that are favorable to knock (i.e. pre-detonation), and pulls timing from the engine in order to prevent knock from occurring.

Note: you cannot HEAR knock retard, so "I can't hear my engine pinging, so it must be fine" is not a valid argument. Only way to see if you have KR is to hook up an onboard scanner and do some WOT pulls.

Anyway, when the car's computer pulls timing in the form of KR, that loss of timing = a loss of power.

Several things can cause KR in a stock car, the biggest culprit being bad gas (from point 1). Also, hot weather can cause more KR than cold weather. What were the outside conditions when you performed these tests?

4. Has anyone yet hooked up an HP Tuners suite to these cars to see how restrictive the Torque Management is on these vehicles? Not much I can say on that unless someone's actually done the work to see if TM is holding the auto's back. If TM is an issue, a simple retune could fix that.

Anyway, hope this helps in figuring out what the issue may be.

GREAT info. I learned something today. And I stand corrected on the wheel issue. HOWEVER. It doesn't count for the fact that GM advertised a performance level that some are not getting using the same stock settup. AND, I think it should be up to the dealer and GM to test all of this stuff for us. They DAMN sure won't reimburse us for whatever money we decide to spend elsewhere.

Welcome to the site. Please visit more often with advice. You are apparently knowlegable.