Why is my car so slow??
#1
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Why is my car so slow??
My car is a 99 Camaro A4
Here are my mods:
Vig3200 stall, 3.73 gears, K&N FIPK, SLP 85mm MAF, replaced steel driveshaft with aluminum one, and the Diablosport programmer. When my car was completely stock it ran a 13.45@103 with a 2.09 60 ft on street tires. After my mods the fastest I've ran was a 13.58@99 with a 1.87 60ft . I run on M/T E.T. Streets so I dont spin. I dont understand why its going slower than it did when it was stock. I know my mph would be slower cuz of the gears and converter and the fact that its not spinning like the stock tires did, but i dont see why my times are not faster. Does anybody have any idea what might be causing this slowness?? thanks.
Here are my mods:
Vig3200 stall, 3.73 gears, K&N FIPK, SLP 85mm MAF, replaced steel driveshaft with aluminum one, and the Diablosport programmer. When my car was completely stock it ran a 13.45@103 with a 2.09 60 ft on street tires. After my mods the fastest I've ran was a 13.58@99 with a 1.87 60ft . I run on M/T E.T. Streets so I dont spin. I dont understand why its going slower than it did when it was stock. I know my mph would be slower cuz of the gears and converter and the fact that its not spinning like the stock tires did, but i dont see why my times are not faster. Does anybody have any idea what might be causing this slowness?? thanks.
#3
Launching!
Re: Why is my car so slow??
Toss the stock MAF back in and see what happens. Most tuners prefer the stock MAF over aftermarket ones. I think it is a hit or miss mod. You may have missed. Its worth a shot. What about the weather? In order to compare times the weather has to be similar as well as the track.
Matt
Matt
#4
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Re: Why is my car so slow??
it was about 15* warmer out but the humidity and pressure were almost the same. But even with my mods shouldnt i have gone faster than a 13.58. I was expecting 13.0's - 12.90 like everyone was saying it would go after the converter and gear. when i got the converte installed i went to the track and it only picked up like .25 and the gear only picked up .1 .I was kinda dissapointed to spen $1500 for .3 something cant be right. I will try to put the stock maf on and see what it does.
#6
Launching!
Re: Why is my car so slow??
I would expect you to be running high 12's with your setup. You don't have a catback correct? Maybe A-tap it and see if that can shed any light. But definately put the stock maf back on. Oh yea, and get a catback or atleast a cutout.
Matt
Matt
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#8
TECH Senior Member
Re: Why is my car so slow??
" I know my mph would be slower cuz of the gears and converter"
A good converter and gears should both INCREASE trap speed, not decrease.
Weather is a huge factor. Don't underestimate that. You should Autotap to make sure everything is in order. Make sure you're not getting some knock retard and that your O2 readings look good. Putting it on a dyno with a wideband O2 sensor wouldn't be a bad idea either.
A good converter and gears should both INCREASE trap speed, not decrease.
Weather is a huge factor. Don't underestimate that. You should Autotap to make sure everything is in order. Make sure you're not getting some knock retard and that your O2 readings look good. Putting it on a dyno with a wideband O2 sensor wouldn't be a bad idea either.
#10
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Re: Why is my car so slow??
i will put the stock maf on tonight. I have the flowmaster american thunder kit.
chazls12002- how do i get it tuned for what i had? and would it be worth it for just the mods i have? i fixed the shifting problem with the predator.
drew778- the car has 50,000 dont know iof it has stock plugs but the wires look stock. I was thinkin about changin the plug probably this weekend. My wires look fine no cracks or nothin.
chazls12002- how do i get it tuned for what i had? and would it be worth it for just the mods i have? i fixed the shifting problem with the predator.
drew778- the car has 50,000 dont know iof it has stock plugs but the wires look stock. I was thinkin about changin the plug probably this weekend. My wires look fine no cracks or nothin.
#12
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Re: Why is my car so slow??
You should post the detail from both timeslips.
You can try to swap out the MAF, but it sounds to me like you have either
-low shift points OR
-car is going into low timing tables OR
-something is mechanically wrong OR
-it's very very very hot in Kansas
The gears will give you mostly MPH ie top end but not help a ton with ET at your power level.
I think you should run 12.7@107mph.
You can try to swap out the MAF, but it sounds to me like you have either
-low shift points OR
-car is going into low timing tables OR
-something is mechanically wrong OR
-it's very very very hot in Kansas
The gears will give you mostly MPH ie top end but not help a ton with ET at your power level.
I think you should run 12.7@107mph.
#13
Re: Why is my car so slow??
Did you have TM deleted. That could be hurting you. Believe it or not, the ET streets might be slowing you down too. Try a buddies nittos or something. I friend of mine has both sets of tires and actually goes faster with the nittos. Like 2 tenths faster. Prolly something to do with taller tire and more rolling resistance.
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Re: Why is my car so slow??
The '98-'00 SLP MAF leans cars out. Predator tune
does not anticipate this and may not play well on
top of false airflow data. Predator does delete TM
and you should first use it to view your WOT O2
voltages, KR, ECT, IAT and upshift MAP values
(telling you mixture, spark setting's
compatibility with it, operating temps' possible
influences and the degree to which the intake
tract may be limiting you).
does not anticipate this and may not play well on
top of false airflow data. Predator does delete TM
and you should first use it to view your WOT O2
voltages, KR, ECT, IAT and upshift MAP values
(telling you mixture, spark setting's
compatibility with it, operating temps' possible
influences and the degree to which the intake
tract may be limiting you).
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Re: Why is my car so slow??
At WOT the KR was about 3.40-50, the ECT was 205*, IAT 95*. What is the KR supposed to be at at WOT? Since the KR is where its at do I advance or retard the timing to fix it(if thats not normal, I dont know. The stock MAF actually flows more air than the SLP MAF did. I think the MAF reading was 30.52 .I really appreciate all the help I'm getting
#16
TECH Senior Member
Re: Why is my car so slow??
KR is supposed to be 0...
what kinda timing are you getting?
I recently ran my car and cut a beautiful 13.3 ... was only getting 12 degrees of timing advance...
KR will hurt you especially if it's that much constant...
My problem was I was getting tossed into the low octane ignition tables plus getting KR taken out... next pass I went 12.3 and picked up over 8mph with timing up to 24 (still having some KR issues)
Before advancing timing make sure it's false knock... put some higher octane (100) in ... if you're still seeing knock then it's prolly false... just be careful not to advance timing too much..
Also may want to try a run w/out the predator tuning in it, then with it... it may be leaning you out too much. Finally... after replacing the stock MAF did you do a PCM relearn? (pull PCM IGN and PCM Bat fuse w/key in RUN... wait a bit then put bat back in then IGN)
what kinda timing are you getting?
I recently ran my car and cut a beautiful 13.3 ... was only getting 12 degrees of timing advance...
KR will hurt you especially if it's that much constant...
My problem was I was getting tossed into the low octane ignition tables plus getting KR taken out... next pass I went 12.3 and picked up over 8mph with timing up to 24 (still having some KR issues)
Before advancing timing make sure it's false knock... put some higher octane (100) in ... if you're still seeing knock then it's prolly false... just be careful not to advance timing too much..
Also may want to try a run w/out the predator tuning in it, then with it... it may be leaning you out too much. Finally... after replacing the stock MAF did you do a PCM relearn? (pull PCM IGN and PCM Bat fuse w/key in RUN... wait a bit then put bat back in then IGN)
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Re: Why is my car so slow??
At WOT the KR was about 3.40-50, the ECT was 205*, IAT 95*. What is the KR supposed to be at at WOT? Since the KR is where its at do I advance or retard the timing to fix it(if thats not normal, I dont know. The stock MAF actually flows more air than the SLP MAF did. I think the MAF reading was 30.52 .I really appreciate all the help I'm getting
ECT is about 10F higher than stock 'stat. Start by
setting your FAN1 on/off to something like 185/180.
This will run your low speed fan full time when
warmed up, and your thermostat will hold you at 195F
or so.
You don't know what the MAFs really flow at identical
pressure drop. All you know is what the PCM interprets
the MAF output frequency as. The MAFs that lean you
out, do so by under-reporting airflow (as a lower-than-
stock output frequency / airflow scaling).
If you must use the SLP then you should adjust the PE
"****" with the Predator to get 900mV WOT O2 voltage
at the top end. This should get you out of any WOT KR
although you will still likely have some transient KR
when you move the pedal, and since KR has a "persistence"
it may cost you a little.
If you can't get over 900mV WOT O2 voltage with the
range the Predator gives you, then ditch that lying MAF
and put on the tried-and-true. Give it some driving time
to get your closed loop relearned, during which you may
see some soggy behavior that eventually goes away again.
Get your O2s right and then dial the spark forward 'til
you start to see KR, then back it off 1% or so.
#19
TECH Senior Member
Re: Why is my car so slow??
Found out why its slow HP=295.8/ TQ 308.6.
Those numbers aren't all that bad... my car stock w/lid and filter put 308/318 and ran 12.85 on street tires (cool day w/light weight driver mod... aka not me drivin)
I know another guy who put similar numbers down and ran 12.7 w/a converter.... lick that KR issue and you'll run alot better....
#20
Re: Why is my car so slow??
Get rid of that MAF, your 99 PCM was designed for a 75 mm MAF and thus its MAF table goes from 1500 to 12000 Hz where a 85 mm MAF was designed to start at 750 Hz.
That MAF will confuse the PCM and you will lose performance with it and there is zero reason for a slightly modded engine to need more (unmetered) airflow to induce more knock and wacko fuel trims.
I spent a solid month testing MAFs and the best results were with the stock one.
That MAF will confuse the PCM and you will lose performance with it and there is zero reason for a slightly modded engine to need more (unmetered) airflow to induce more knock and wacko fuel trims.
I spent a solid month testing MAFs and the best results were with the stock one.