My 99Z couldn't beat a 6 cylinder Mustang

**Vision** · 10-04-2005, 04:14 PM

aka: "the my car is a big steaming pile of crap" rambling.

forgot what my old LS1.com user ID was/is . . .

I'm driving to work today in my 99 Z28 M6 after making my way through traffic, it hit a wide open stretch with no cars in front of me and no place for cops to hide. I bring my speed up to 85 or so (in a 65) and I'm cruising along in the left lane (on I-55 in Joliet, IL area) when I see a new Mustang coming up quickly. I'm about to change lanes to let him pass since I'm freakin 29 and don't have the urge to race anything remotely sporty on four wheels (and the fact that my car is glacier-slow by almost any definition). When he/she tries to get into the right lane and flyby before I get over. I'm caught in both lanes and now I have an angry (and ugly) Mustang on my rear bumper. No big deal, but I'm kinda annoyed so I downshift to 3rd and gun it. Hmmm . . . Usual results, the car goes nowhere and has no pull at all and the Mustang isn't getting smaller in my mirror. I hit traffic at the next exit and slow down, he/she gets off after flashing their hi-beams in anger and I notice it's a 6 cylinder as it passes by.

Man I hate my car. It's almost bone stock with only a lid and K&N, but these cars should be good for 165mph and mid 13s bone stock. I swear I got a runt. An LS1 should be able to walk away from a new Mustang GT, not to mention a 6 cylinder Mustang. Every LS1 I've been in absolutely rips at any speed, especially at highway speeds- even stock ones. Mine has no balls at all. It has a fresh tune up, fresh top end cleaning, fresh oil change, no engine codes. Nothing has helped it. It honestly pulls weaker than my old L98 thirdgens on the expressway- and L98s fall flat at 4500 rpm. It disgusts me to even think about it. I'm not even going to waste my time modding it. Maybe it was broken in poorly. I'm finding more and more evidence that the previous owner was a lazy, crooked asshat that didn't really take care of it. Guess I should have beat on it during the test drive to see what was really going on.

A couple weeks ago, I couldn't pull away from a newer Monte Carlo SS Intimidator. Then there was the 96-98 Cobra that would have walked me if not for traffic at the time. I really don't go flying around or looking for races, but when the opportunity comes to put the smack down, I just get underwhelmed. All I'm really doing is embarrassing the LS1 name.

That is all. I don't really expect a response, just needed to get that off my chest.

**SKULLZ** · 10-04-2005, 05:41 PM

paint SLOW on the side of your car, so the rest of us dont look bad

**LS1-450** · 10-04-2005, 06:21 PM

Sounds like a real piece of

I'll give ya $1,500 for it so you won't have to suffer with it any more.

02 WS6 · 10-04-2005, 06:25 PM

maybe take off the Z-28 badging and replace it with the RS badging.....the losses might look more reasonable to the winners and allow you to retain some respect, as they will think its a v-6. J/k....

Seriously, I would take it to a f-body shop and see what they say....it maybe something simple....somethings wrong....
There are some good shops around here that know whats going on...it would be worth a few bucks to see what they say.

p.s. Im near I-55 and Weber....in the hood

**ncbandit75** · 10-04-2005, 06:49 PM

hey i got an rs , with a 355 lol , wait till i slap sum 2.8 badges on tha side!!

**Vision** · 10-04-2005, 07:45 PM

I had a 92 RS with the 305 tbi that might have given my 99 Z28 a good run . . . And my RS was SLOW. I used to call it the Camaro Really Slow. Maybe I'll swap in a 2.8 and call it a Z2.8.

**SeVeReDiStOrTiOn** · 10-04-2005, 09:50 PM

maybe it's pulling some serious timing?? My auto's kinda slow on the highway...unless it kicks down like it's supposed to. Bring it into a performance shop ahd have them check it out....try a dyno tune also and see what it pulls.

**third_shift|studios** · 10-05-2005, 06:06 AM

Originally Posted by ncbandit75

hey i got an rs , with a 355 lol , wait till i slap sum 2.8 badges on tha side!!

i made this for someone, you can toss these on it:

**toneloc60** · 10-05-2005, 08:13 AM

How many miles on it? Is the clutch slipping?

I'd say take it up to Speed Inc. in Shaumburg. Go to there site LS1SPEED.COM
Maybe they can answer some questions for you.

By the way, always work a car on a test drive. Before I bought mine I thought the salesman was going to leave claw marks in the dash.

**ibanez7** · 10-05-2005, 08:25 AM

I agree with the idea above, I live in the NW suburbs of chicago and shop Speed Inc. all the time. Great shop, great people.

Go there and have them check your air, gas and spark mapping, maybe something in the computer or with a sensor isnt working properly and isnt throwing an SES code.

MIGHT BE A TPS ISSUE!!![/SIZE]

Also consider your TPS (throttle position sensor), if your TPS is acting up, it will not through an SES code. When your at WOT (wide open throttle) your TPS might being sending a signal to the comp that your actually at 40% not WOT. Hence makeing for a slow car.

The TPS went out on my 01 z28 m6, didnt throw and SES codes either. All it did was raise my RPM, it kept telling the computer that the throttle was open more then it actually was. I would be driving along press in the clutch, while off the gas and the RPMs would surge.

When a TPS goes out, it causes all different types or erratic behavior. The TPS is just a potenimeter that cost about $33.00 at autozone. Easy to install too, just two screws on the side of the throttle body.

**Ayeris** · 10-05-2005, 08:46 AM

sounds like you got a big dud there. are you sure you have a LS1 in there not a 6 banger misbadged?

**Vision** · 10-05-2005, 09:21 AM

Thanks, I'll try some of the easier things suggested.

I'm kinda leery of Speed Inc. Seems people either love them or HATE them. I've heard almost as many horror stories as good with them. Guess that's any business. I really just don't have time to take it anywhere.

Clutch has maybe 2.5k miles on it along with the pilot bearing, throwout bearing, flywheel, and pressure plate. Hey, my car's so slow- I didn't have to worry about beating on it during the clutch break-in. The car has 71k on it.

**02z28ls1** · 10-05-2005, 04:59 PM

At 85 mph you throw it into 3rd?What rpm is that?Anyway if it were running right like mine you wouldn't need to downshift that far-it would pull like a striped ass ape in 4th or 5th-and yea -it would continue to pull past 150.

**Redegal** · 10-05-2005, 06:37 PM

If I were you I would try to narrow down the symptoms first before dropping it off at a speed shop and telling them it's "slow". Could it be a clogged catalytic converter or maybe even a clogged airfilter? How many miles are on the car? It could be TPS. Good luck and try not to lose patience.

**mogs01gt** · 10-06-2005, 09:49 AM

sell it and buy another one

.

**Vision** · 10-06-2005, 11:04 AM

Originally Posted by 02z28ls1

At 85 mph you throw it into 3rd?What rpm is that?Anyway if it were running right like mine you wouldn't need to downshift that far-it would pull like a striped ass ape in 4th or 5th-and yea -it would continue to pull past 150.

Actually, I was going closer to 75 by the time I changed lanes. 3rd gear at 85mph would be around 5000rpm I think.

**sscrazy** · 10-06-2005, 06:28 PM

Originally Posted by 02z28ls1

At 85 mph you throw it into 3rd?What rpm is that?Anyway if it were running right like mine you wouldn't need to downshift that far-it would pull like a striped ass ape in 4th or 5th-and yea -it would continue to pull past 150.

hmmmm, my 3rd gear pulls past 95 mph. oh ya i go to 7000 rpm lol

rays00ramair · 10-19-2005, 05:36 AM

unhook the batery overnight.pul the pcm fuse under the hood.this clears the temporary fuel and spark tables then fire it up.well start it and when it idles shut it off,sets the idle table up.then go hammer the shit out of it.i do this b4 i go racing the next day.have seen a coupla tenths doing this.or maybe the weather but it feels stronger.

sickbitch02 · 10-19-2005, 12:11 PM

well, from experience, i would try disconnecting the battery overnight - sometimes the computer just needs a good reset, but if you're not throwing any codes, i would seriously take it somewhere that you trust and just have them take a look at it. it may have to do with the timing. also, check the wires to make sure they are in good condition, you know, not showing arking signs or have any cuts or frays. thats all i can think of right now, but if i come up with anything, i'll let u know. cuz somethings not right with that. =(

**Formula** · 10-19-2005, 03:08 PM

Check your throttle cable:
Open the hood and have a frend press the gas pedal all the way down and make sure your throttle fully opens (the cable is adjustable.)