Where is my MPH going.....?
Where is my MPH going.....? Well, after the recent round of mods, I am not to impressed. Last year, with a lid, 3.23's, smaller converter (MW 3400), and exahust, my car went 12.7@107 on a 1.8 60'....fast forward to now. I now have LS6 intake, ASP pulley, cam (232/238 112LSA), bigger converter (PT4000), slicks and skinnies, LS1 Edit (this is where I am probably not setup good at), still on 3.23's (probably gonna upgrade to 3.73's this winter) and probably a few other things...my best so far is a 12.2@111.5 on a 1.7 60'...I have it shifting around 6300 now, which is probably leaving a bit out, but with 90,000 on the motor, I dont want to spin it much more. Advancing the cam should bring the power curve down in the RPM range right? I might try it.Raceweight everytime has been around 3500-3600. Does that seem right..? Maybe some/alot of it has to do with tuning. It seems to run pretty well, but I have yet to dyno tune it...
I see all these stock internal A4 cars running 11's @ 115. Hell, I had a buddy here in OKC run 12.3@113 on a 02' WS6 M6 with lid, headers, and tuning. How much could be do to the DA? The regular altitude of the track is around 1200 ft, and I think I calculated a DA of 1600 or so last time out. Surely it isnt killing it that bad.
Any ideas....?
EDIT: a TNT 75 shot pushed it to a 11.7 @ 117
I see all these stock internal A4 cars running 11's @ 115. Hell, I had a buddy here in OKC run 12.3@113 on a 02' WS6 M6 with lid, headers, and tuning. How much could be do to the DA? The regular altitude of the track is around 1200 ft, and I think I calculated a DA of 1600 or so last time out. Surely it isnt killing it that bad.
Any ideas....?
EDIT: a TNT 75 shot pushed it to a 11.7 @ 117
Last edited by JxxxOxxxE; Nov 5, 2003 at 12:50 AM.
I was just looking at some ATAP logs, and I am only getting around 25*-26* of timing, doesnt that sound a little low?
I am also noticing about a 100 Mv difference in the O2 sensors....?
Loco, what do you MPH at?
I am also noticing about a 100 Mv difference in the O2 sensors....?
Loco, what do you MPH at?
Last edited by JxxxOxxxE; Oct 31, 2003 at 02:03 AM.
TECH Resident
Joined: Jan 2002
Posts: 922
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From: In front of my computer
Lots of things could cause it. Tune, tune, tune!!!!!!!!!!
What size slicks you runnin. I always MPH better on drag radials than slicks. That big of a stall is gonna lose some MPH. Looks like you added alot of things at one time. Give yourself some time to figure out your combo. It shall come. Took me 2 years to figure out my combo.
Good luck.
BTW: Thunder valley isnt the best track.
Stu
What size slicks you runnin. I always MPH better on drag radials than slicks. That big of a stall is gonna lose some MPH. Looks like you added alot of things at one time. Give yourself some time to figure out your combo. It shall come. Took me 2 years to figure out my combo.
Good luck.
BTW: Thunder valley isnt the best track.
Stu
Well I would have to ask a couple Q's here first.
1) What size slick are you running?
-if you are running a 28" slick, its going to hurt your MPH compared to a 26" tire. My car saw 2MPH more last year when I tried some 26" tires for a couple passes.
2) Locking the converter? And at what point in your pass?
3) Getting any KR??
4) The LS1 Edit tuning of course could be part of the issue, as well as the shift points.
1) What size slick are you running?
-if you are running a 28" slick, its going to hurt your MPH compared to a 26" tire. My car saw 2MPH more last year when I tried some 26" tires for a couple passes.
2) Locking the converter? And at what point in your pass?
3) Getting any KR??
4) The LS1 Edit tuning of course could be part of the issue, as well as the shift points.
I am running a 26" tire
I am never locking the converter, I have thought about it, but havent found a good diagram on how to wire it it in.
No KR on the runs I was describing
I know I need to play with Edit a whole lot more.
So does the amount of timing seem sufficient? What about the big difference in the O2's?
I went to the track on my 18" ZO6 wheels with Kuhmo tires, and ran a 12.8@111 with a 2.0 60'. The later switched to the slicks, it definitely helped the ET, but I thought I would see some more MPH outta that too. Guess not
I am never locking the converter, I have thought about it, but havent found a good diagram on how to wire it it in.
No KR on the runs I was describing
I know I need to play with Edit a whole lot more.
So does the amount of timing seem sufficient? What about the big difference in the O2's?
I went to the track on my 18" ZO6 wheels with Kuhmo tires, and ran a 12.8@111 with a 2.0 60'. The later switched to the slicks, it definitely helped the ET, but I thought I would see some more MPH outta that too. Guess not
Last edited by JxxxOxxxE; Oct 31, 2003 at 10:33 AM.
A car that spins will often see a higher MPH at the end of the track then a run in which it hooks. Be happy with you times and not so concerned with the mph.. All your slips are telling you is that you are putting the power to the ground.
I think the main problem is that you need to "Tune"... Good luck and let us know how you make out..
-George
I think the main problem is that you need to "Tune"... Good luck and let us know how you make out..
-George
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Verdad Gallardo I have to disagree about not worrying about MPH. To me and most people I race with MPH is what indicates if the car is making any HP or not.
Not locking up the converter on a stock bottom end/compression car is going to cost several MPH from my experience with these cars.
You lock up the 'verter and I bet you'll trap a few MPH more right away just from that. We've gained even more in the past by just making passes and messing around with it and locking it up at different points going down the track..locking it like the top of 3rd gear seems to be a good starting point for most cars with a good sized stall.
Not locking up the converter on a stock bottom end/compression car is going to cost several MPH from my experience with these cars.
You lock up the 'verter and I bet you'll trap a few MPH more right away just from that. We've gained even more in the past by just making passes and messing around with it and locking it up at different points going down the track..locking it like the top of 3rd gear seems to be a good starting point for most cars with a good sized stall.
You are running a huge cam and a stock gear, and a big but not really big converter.
Does the cam have any advance?
I have friends going 113-115 mph with light cars and stock internals.
Do me a favor and post a whole slip.
Does the cam have any advance?
I have friends going 113-115 mph with light cars and stock internals.
Do me a favor and post a whole slip.
I need to get a diagram to wire up a lockup switch. I wonder about longevity of the converter with it being forced to lock up like that. It seems like it would be pretty violent, going from say 5000 rpm to 3000 or so...like a jolt...
The MPH was was I was worried about for the reason Silverghost posted, that I wanted to know what kind of HP the car was making, since putting an A4 with a 4000 stall on the dyno wouldnt tell much.... According to some of the calculators I have come across, and inputting the 12.2@111.5, they state I am putting down around 380-385 HP at the wheels....
The MPH was was I was worried about for the reason Silverghost posted, that I wanted to know what kind of HP the car was making, since putting an A4 with a 4000 stall on the dyno wouldnt tell much.... According to some of the calculators I have come across, and inputting the 12.2@111.5, they state I am putting down around 380-385 HP at the wheels....
well joe I am in the same boat you are!!!
my car is having the same kind of probs
here is my slip
60....1.713
1/8...7.812
mph..87.5 .....what a turd!!!
1/4...12.2949
mph..109.65......again turd
I have a 98 formula
probably weighs 34-3500 w/me
slp longtubes,y/pipe slp dual on the left cat back
yank tp 4000 stall
asp pulley
373 gears
I am shifting the car at 6300 also in first 6250 in 2nd
my car is having the same kind of probs
here is my slip
60....1.713
1/8...7.812
mph..87.5 .....what a turd!!!
1/4...12.2949
mph..109.65......again turd
I have a 98 formula
probably weighs 34-3500 w/me
slp longtubes,y/pipe slp dual on the left cat back
yank tp 4000 stall
asp pulley
373 gears
I am shifting the car at 6300 also in first 6250 in 2nd
TECH Senior Member
Joined: Nov 2001
Posts: 9,246
Likes: 3
From: Troy, AL
6300 with THAT cam? I was shifting at that RPM (and higher) with the STOCK cam and running 113 MPH at your raceweight. Your gearing is low, your shifting is low, your mileage is WAY high, and your converter is so-so for that cam. Your tuning may be way off for all I know. It all adds up but I gotta agree with you, you are leaving alot on the table right now.
I know there is alot left. Its gonna take some time for me to sort everything out.
I will be upgrading to 3.73's this winter, and hopefully doing some dyno tuning somewhere in there.
Heads are getting put on soon too, as I am just waiting for the intake valves to show up
What shift points would you reccommend with that size cam Colonel? I have the rev limit at 6600. I just dont have the money to fix something that breaks right now, by running the car to too high of a RPM. I know, breaking stuff is racin, but I would rather just be smart and safe about it for now. What do you think a stock bottom end 98' with 90,000 can withstand...?
If I advance the cam, won't that bring the powerband down in the RPM range some, to save me from some of the high RPM's...?
I will be upgrading to 3.73's this winter, and hopefully doing some dyno tuning somewhere in there.
Heads are getting put on soon too, as I am just waiting for the intake valves to show up
What shift points would you reccommend with that size cam Colonel? I have the rev limit at 6600. I just dont have the money to fix something that breaks right now, by running the car to too high of a RPM. I know, breaking stuff is racin, but I would rather just be smart and safe about it for now. What do you think a stock bottom end 98' with 90,000 can withstand...?
If I advance the cam, won't that bring the powerband down in the RPM range some, to save me from some of the high RPM's...?
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Joined: Mar 2002
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From: Your Reality Check Bounced...
Shifting that low is killing you...I ran almost .5 quicker shifting around 6800 than I normally like to shift around 6400 cause of the mileage of the motor....I mean you're leaving a lot of power in the lower gears.....
