Ok...so I took my 07 automatic tC to the track when it was stock, right out of the factory, and ran a 16.3 1/4 mile at 84. Now, after this list of mods my car is slower (16.6 at 82) and I am troubleshooting this problem as we speak. Any help or suggestions would be much appriciated, thanks.

Mods:Weapon-R short ram intake, House of billet throttle body spacer, Weapon-R intake manifold, DC Sport Header, Invidia Downpipe, Tsudo midpipe no cat with resinator, Greddy Evo 2 axel back with bigger muffler, house of billet crank pulley, radiator air diversion plate, back seats removed, passenger seat removed, spare tire and accesories removed, carbon fiber hood, 18" light weight wheels, kuhmo spt tires.

The car is not tuned and I do have software coming in the mail that will allow me to tune the car so there is no limits to troubleshooting.

 

Apparently you need to keep your foot on the throttle.

I keed. I keed.

 

9 times out of 10, it would be the driver, not the car. No matter how many mods you have, you're better off improving your driving first.

 

throw the throttle body spacer out it does jack for the tc and two it could possibly be from your rims. although they are light weight you did just up the rotation mass that the tc is used to (17 ") so that could play a part in it

 

Ditto on the TBS. Worthless.

What wheels are they anyway? Like, how much is "light weight" for an 18? The OEM 17s are about 21 lbs or 23 lbs. Could definitely go with some better tires as well.

 

Ur number 1 problem there is you have an automatic!

 

yes sell it get a 5spd

 

The TBS is pointless..also..isn't the intake manifold meant for boosted aplications? And don't you have to be tuned to run it properly?

 

I think you can use the manifold for NA... but ya, you won't get crap out of it unless it's tuned. Not to mention the auto part.

Why people think it is worth taking an auto to a track is beyond me... I mean, I've seen very few people even autox an auto. Sometimes you can get away with it there more than some other types of racing... but damn.

 

Normally, yes... but since he has an automatic, all he has to do is press the 'go' pedal when the light turns green.

Unless they're OZ or something, I kinda doubt your 18" rims are lighter than the stock 17s. Your tires are garbage, too. These two things effectively cancel out the diet you put your car on. One thing that could be causing time discrepancies is fuel load, too. What's your tank looking like when you run?

Oh, and I'm bringing in my crusade against aftermarket pulleys. Take yours off if you like your block.

 

like most people here said 1 st issue and auto....cant do much with them..not meant too be...you did all that work to improve your performance even though you know its and auto...ive read many threads on here people mods auto which is fine but you wont see a big difference as you would a 5 speed...i say trade it in get a 5 speed if you know how to drive one...more control on the car and escpically your speed

 

1. Stock wheels are 19lbs
2. The fact he has an auto is irrelevant


what are your 60ft times?

also try cleaning your MAF and check to make sure your spark plugs aren't fouled. I just had this same issue and spent all of Saturday trying to figure out why i couldn't break 11 sec in the 1/8. Turned out one of my front calipers was not operating properly and was getting stuck from where the brake pistons were dirty and my ceramic pads were dragging

you should be in the mid 15s or so. maybe even slighty lower

 

Intake manifold and throttle body spacer will not do much unless you get your car tune and even after that the TBS might not do anything at all, it might evem hurt you, they are meant for boosted applications.

 

What were your 60' times

Also take off TBS
Make sure your rims are actually light weight
Good tires
Take off intake mani
Send back whatever you just bought to tune your car
Put your passenger seat back in
Try it again, Its probably just your 60' that sucked.

 

remember, even if your rims are "lighter weight" you put on bigger tires that probably weight more than the stock tires, so it wasn't a big deal.

 

Ok so I know the 18" rims may slow me down a little thats why I posted it to show everyone all the facts but they shouldnt slow me down that much. They are motegi ff7's, is that lighter, im not sure?

Why are kuhmo spt a bad tire and what do you suggest?

Dont make me laugh when you say bad driver, it's an auto you brake launch and hold the throttle to the floor, not rocket science.

Stock 60 FT:2.4933
New 60 FT:2.5111

Steventc07: I recently cleaned and oiled the intake, when you say clean the MAF do you mean the actual sensor or did you just mean the intake? Also, how did you come to the conclusion that your caliper was getting stuck and whats the best way to check the spark plugs?

I have read that the throttle body spacer and the crank pulley are both bad ideas. But, with the tune will that help the throttle body? Also, I put my car up on a couple stands yesterday, took off the passenger tire to get to the crank. I was going to take off the crank and put the stock back on but I couldnt find any place to rent an impact wrench on sunday.

I am going to find one though and test my car in a 0-85 mph run with and without an aftermarket crank pulley to see the difference if any. But, the results may no be accurate for all tC's seeing that something is wrong with mine.

On the stock run my car was at a 1/4 of a tank maybe a little lower on 93 octane. On the new run I did a couple runs on 93 octane at 1/8 of a tank then mixed race gas with that to a 1/4 of a tank. Never broke 16.6 either way.

Reguardless if the car is automatic or standard there should still be an increase in performance. I am trying to figure out what is hindering this performance not that this performance could be better if the car was standard.

What is TBS?

 

Sorry I feel dumb TBS = Throttle Body Spacer

 

lol, why did you put race gas in an automatic tC?

 

I put race gas in for fun.

Update, Not sure if this is of importance or not but I went to Auto Zone and got an OBD II scan and came up with these results.

1) Catalyst system efficience below threshold (well this is obviously because I have no cat).
2) Evaporative emission control system incorrect purge flow
3) Evaporative emission control system pressure leak detected - large leak

I know what is wrong in #1 but can someone enlighten me with #'s 2 & 3, and would it have any effect on acceleration?

 

#2 and #3 are from having a loose gas cap, most likely.