Trapping too low?

[ChrisMustang]

Is my car trapping too low?

Mods are magnaflow catback, unknown possibly steeda cai, 2.81" pulley, tr6ix plugs and mail order tune. Nothing else, no idlers or anything.

Before my pulley and tune I was able to get a 12.998@109mph.

Now after the pulley my best time was [email protected]. I had a couple runs that were 112.

But shouldn't going from stock pulley and tune to a 2.81 and tune net me more than 3mph?

On my runs with the pulley I had a shorter tire, about 1 inch shorter, would that effect my trap speed?

 

[96stanggt]

Yes, unless you live at a crazy high altitude you're trapping low. Have you datalogged your car or put it on they dyno to check power/afr after the pulley and tune?

 

[derockgt]

that does seem low, When i missed fourth(grinded..) i still trapped 112. usually see 117-118. it could be a really safe tune and pulling timing. i would go get it on a dyno and have the tune looked at.

 

[ChrisMustang]

Thanks guys. I will datalog and see what i get. I was hoping not to dyno tune it until my next batch of mods.

 

[mach1033]

Who did the mail tune? You might be running a conservative tune that is way rich. Do you have a wide band and boost gauge?

 

[earico]

I'd datalog IAT2s on the big end of the track. PCM might be pulling timing at the end of the run. Could be intermittent IC pump.

What was the 1/8" MPH? If it's near normal then I will bet on the IC pump theory.

 

[ChrisMustang]

Who did the mail tune? You might be running a conservative tune that is way rich. Do you have a wide band and boost gauge?

American Muscle/BamaPerformance I do not have a wide band or other than stock boost gauge.

I'd datalog IAT2s on the big end of the track. PCM might be pulling timing at the end of the run. Could be intermittent IC pump.

What was the 1/8" MPH? If it's near normal then I will bet on the IC pump theory.

1/8 mile was always around 88.50.

 

[earico]

1/8 mile was always around 88.50.

That's within a couple mph of the normal pace for a pullied car. I bet your IC pump is weak and IAT2s are high by the middle of 3rd gear.

How long did you let the car cool down between runs?

 

[ChrisMustang]

Didn't, I hot lap the thing. all runs were 111-112 mph.

 

[earico]

Didn't, I hot lap the thing. all runs were 111-112 mph.

There is the problem. If you would let it cool with the hood open for 30-40 minutes between runs it would trap higher. Welcome to the wonderful world of PD blowers and heatsoak. It's just par for the course.

 

[Kwik03DSG]

There is the problem. If you would let it cool with the hood open for 30-40 minutes between runs it would trap higher. Welcome to the wonderful world of PD blowers and heatsoak. It's just par for the course.

Well depends on what he trapped first. I remember when I first ran at the track, even hot-lapping in 85-90* humid south Texas weather I would trap 121, 119 118, 117, 114.5 hot lapping all 5 runs. MPH sank 1-1.5 each run.

Never saw a trap that low lol. I'd bet it's a combination of factors but he still needs to data log and check that IC pump.

*disclaimer* my 12.09@121 was on a tune that wasn't exactly safe. 2.76 upper, jlt intake, bbk xpipe, accufab intake and plenum... Lean ass diablo tune 12.5 AFR and 24 degrees timing.. :dw:

 

[ctgreddy]

yeah the previous owner of my car when it was the same mods as yours along with a catless midpipe, trapped consistently in the 113-114 area until he let it sit for a little over an hour(no ice just sitting on a 70* day) and after that it trapped 117.8. so next time let it cool for aobut 45 minutes, throw some ice in your intercooler reservoir and go run and i bet you it's a better trap.

 

[lucheski]

i had an issue with the iridium plugs breaking up at WOT in the higher rpms. Make sure they are not gapped too wide. For a few dollars you can put in the NGK TR6 standard plug gapped at 030 and re-run the car.

 

[ChrisMustang]

My plugs are gaped too wide, My idle is rough after switching to these plugs, but the car always seems too run fine anything above idle, so maybe I am seeing some issues in the top end too.

 

[ChrisMustang]

I wasnt sure what to data log so i logged fpdc and iat and rpm

Fpdc seems to be maxing out. at idle its around .200 then around 3800 rpm it gets to .2980 then from there it spikes to .4999 by 5400rpm sometimes, but other times when running to 6000 the fpdc stayed between .4650 to .4740.

I really dont know if im reading this stuff right or not, first time trying to log anything.

 

[ChrisMustang]

I'd datalog IAT2s on the big end of the track. PCM might be pulling timing at the end of the run. Could be intermittent IC pump.

What was the 1/8" MPH? If it's near normal then I will bet on the IC pump theory.

I cant find a IAT2 on the tuner(sct livewire). Only has one intake air temp.

I can log 6 at a time. choices are.

-Battery voltage
-coolant temp
-desired idle rpm
-fp duty cycle
-idle spd valve dc
-intake air temp
-load
-lt fuel trim b1
-lt fuel trim b2
-maf counts
-maf voltage
-maf cts (03-04 cobra)
-rpm
-short term trim b1
-short term trim b2
-spark
-thrt pos absolute
-vehicle speed
-v speed(03-04 cobra)
-thrt pos absolute... (not sure why its listed again)

 

[earico]

I cant find a IAT2 on the tuner(sct livewire). Only has one intake air temp.

I can log 6 at a time. choices are.

-Battery voltage
-coolant temp
-desired idle rpm
-fp duty cycle
-idle spd valve dc
-intake air temp
-load
-lt fuel trim b1
-lt fuel trim b2
-maf counts
-maf voltage
-maf cts (03-04 cobra)
-rpm
-short term trim b1
-short term trim b2
-spark
-thrt pos absolute
-vehicle speed
-v speed(03-04 cobra)
-thrt pos absolute... (not sure why its listed again)

Link:

http://www.svtperformance.com/forums/engine-tuning-214/591470-datalog.html

 

[ChrisMustang]

Any thoughts on this?

Fpdc seems to be maxing out. at idle its around .200 then around 3800 rpm it gets to .2980 then from there it spikes to .4999 by 5400rpm sometimes, but other times when running to 6000 the fpdc stayed between .4650 to .4740.

I really dont know if im reading this stuff right or not, first time trying to log anything.

 

[ChrisMustang]

Sorry to bump my own thread, can anyone give me insight on my FPDC? Does all that mean I am maxing the pumps?

 

[Swervedriver]

How much gas was in the tank? Yes .4999 is pegged.

My car had a leaky PPRV so when I put an early apten port and 2.76" pulley on it the AF would swing above 12:1 above 5k rpm and would get up to 13:1 lean above 6krpm.

A simple boost a pump took care of the lean issue until I dropped the pan to install GT pumps several years later.

It even dynod 545rwhp on a small 50 shot with those stock pumps, 60lbs injectors, and the BAP.