When I got my z it felt really quick, but after riding in a few other z's mine feels really sluggish in comparison. my z now has a plenum spacer, throttle body spacer, test pipes, y pipe and exhaust, but it still feels slower than my friends bone stock z. My car is on 20's (not my choice, just havent felt like dropping money on 18's) but when i put on my friends stock 17's it still didnt feel any faster, and still felt slower than other z's that ive ridden in. I know I need a tune, but having my car feel slower than others just like it has really gotten me down, any suggestions on things to test/check/replace? I don't really care about my car being fast, I'm all about fun and driver experience, and i just wish my z would put me back in the seat like the others ive driven/ridden in.

Thanks,
David

 

clean the throttle body if its dirty. makes a noticeable difference

 

I already cleaned it using one of the writeups on here, wasnt very dirty and i didnt notice any difference...

 

Thanks for your quick response though!

 

air leak anywhere?

 

What kind/grade of fuel are you running?

 

No vacuum leaks or anything, it idles perfectly fine and drives perfectly fine. i run only premium. it just doesnt ever put you back in the seat the way other 350's do. i always thought it was the big heavy 20's that made it feel slower than the others, but when i put on the 17's it still felt sluggish.

 

You answered your own question.
You need a tune.
When did this "sluggesness" start?
Have you checked compression and what others have mentioned,
vacuum leaks?
Just for the heluva it,I'd put some Seafoam in your gas.
See if any changes...



With all your bolt-on mods,your car needs to
be brought in balance to take advantage of the parts.
Some things like a throttle body spacer are marginal in
doing anything.
I'd bet you are getting poorer mpg too...
The size of wheel is not the problem.To be sure,say 18's would
be better.But,you are not gonna track your car,right.
Simply,a engine is a air pump.It appears that you are getting air
in&out(I'm assuming you also have the obligatory CAI/CAI'S?).
But,there is something in the process that is not as efficient
as it should be.Is there a good Z tune shop near?Charlotte?
Z-1 is in Atlanta.The guys there will find the HP that you are hiding.
Good luck

 

The car felt sluggish in stock form compared to other stock z's, I guess i wasnt very clear. I bought the car, everything was fine, then my friend bought a stock z and his felt much much quicker than mine did. THEN i modded mine, and it still feels exactly the same. Everything is fine as far as i can tell, and there are definitely no vacuum leaks. TB is clean, MPG's are great (26 combined). I just dont want to go tune it (i know a shop in charlotte that a couple friends have gone to) and have poor numbers because of something i overlooked. I'm going to change the spark plugs (car is at 112k miles, dont know if they were changed at 100k) then set up an appointment to get it tuned and hope for the best. on a side note, if anyone has any stock touring v2 wheels, send me a PM :P

 

Your feelings are important to you but mean little to me.

Performance measures such as 1/4 mile ET are also of limited value. Without dyno results we have little to work with.

 

Dyno time with a tune...proper AFR, timing...ESPECIALLY if you have the original plugs at 122,000 miles.

 

with that many miles on your car, try a sea foam treatment.

 

Um, TP's lose power and torque low down.

TB spacer has been tested to give no gains, i wouldn't be surprised if it was causing problems.

Have you performed any servicing on the car, plugs oil changes etc. Have you checked for binding brakes?

Your 20's will kill it, don't care if it still feels slow without them, they're killing it.

 

Some people have serious comprehension problems. THE CAR FELT SLOW COMPLETELY STOCK. The test pipes didn't cause me to lose torque when they weren't installed on the car. Yes I have done all of the maintainence, changed out the plugs today, change oil every 3750. Changed the brakes a few months ago, no binding. Again, I understand that the 20's are killing it, like I originally posted. And davidv, the car feels sluggish to the point where other people wonder why it isn't as quick as another z. I just don't want to dump money into a tune when something clearly isn't right. Any other input on the TB spacer? I have no opinion on it, Its on there because the previous owner put it on and I didn't ever notice. Guess I'll remove that and see if it feels any different, though I doubt an inch and a half of extra intake is really gonna make a difference.

 

David throw your car on a dyno. It costs like $40 and you will see what kind of numbers you've got and then that'll tell you if it just "feels" slow or if something is actually wrong. I think you just need a tune. Mine was the same way then CIN tuned it and now it feels a whole lot better.

 

nobody has mentioned the MAF sensor yet. Dont know if you cleaned that the same time u did the TB. IMO its helped recapture some of the HP in my car that has 86k miles on it

 

I guess I'll go ahead and call CIN, I think I've just been getting cold feet about getting it tuned. I want a ride in yours by the way, I've never been in the 5AT. Thanks guys, sorry for the hostility it was 3am and I was aggravated with my car already haha.

 

Just a quick follow-up, i removed the TB spacer just for the heck of it, and theres definitely a difference. Throttle response is much better and it definitely pulls a tad harder. Looking inside the TB spacer it seems very restrictive, it has a lip that goes around the inside that's significantly smaller than the intake is.

 

Yeah not all mods are beneficial.

 

Motordyne tested TB spacers etc, they found nothing to be gained from that area at all.