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casper is correct. Common sense says if your telling the SCT tuner you have 4.10s, then it's telling the computer u have 4.10s. That is why the one fellow didn't have a problem because you had changed it. This is not a fact just thinking; i would assume in most case with leaving the tranny in D it would be short shifting, as in manually shifting would over rev your tranny, thus the reason your times were slower. is that correctc asper?
 

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^^^^^^Casper is always correct.

he's like the Jazzer of auto transmissions. :lmao

reppin' cause i love learnin new stuFF. :D :rockon
 

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Discussion Starter #24
Tuner back in

Got the tune back from sct. Took the car out and ran her hard. Then did 3 est 1/8 mile runs on a clear highway. All is well runs like a mustang should
 

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SO IF YOUR WANTING TO RACE 1/8 MILE MAKE SURE U GET A TUNE WITH THE GEARS OR U ARE WASTING UR MONEY JUST FYI:yes
:no

With the auto trans tuning issues aside, you won't be "wasting" your money on gears if you don't get a tune.

This is more for the manual crowd, but don't be scared from getting gears if you don't have a tune or tuner. You're not going to be slower in the 1/8 or 1/4 mile by putting in steeper-than-stock gears. I'm guessing the reason this guys wife's car is slower because they went from a performance tune to a stock tune.
 

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by your shift point comments I have to assume the car is an auto, if thats the case, quit driving it without a tune for the gears unless you want to put a trans in it (if it's not to late already).

electronic automatic transmissions use numerous inputs to opperate (from battery voltage to throttle posision to road speed & everything in between) the cannot tolerate a gear swap without a tune immediately (ie. have the tuner in your hand ready to install the tune before you drive the car for the first time with the gears).

I hope it works out ok for you, but quit driving the car till yo have the tuner.
Digging back into this because I was thinking about it. Hopefully Casper comes back in here to answer. But WHY does it matter to the tranny what the ratio is? It doesn't seem to me that it would matter. What tranny input is effected by changing the ratio? :dunno

The ratio is changed after the tranny. It's essentially like saying changing your tire size can destroy your tranny. :confused:
 

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I'm really glad i learned about this...idk how long the previous guys had gears in but i know he had a s/c on the car before trading it in.

When i got the car the speedo was off though and has been since 24k miles and im up to 43k...no problems though! I'm gonna be ordering a tuner though friday when i get my paycheck :D

If i normally run the 87 octane, will a "performance tune" for the 87 not make much difference at all? I dont ever drag or anything. So i was thinking about getting and 87 octane economy type tune, 87 octane performance, and the a 91 octane performance just for kicks...
 

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This is to SonicBoom, and I'm just spitballing. If I'm completely off base I'm not going to be sad.

I would assume it's bad for the transmission to take in your rpm, throttle position, load, etc. into consideration and then make it's calculations based on a vehicle speed that is different from the actual speed the vehicle is going.

This is a stretch, and I doubt if my numbers will be right but it's just an example. If you put in gears and don't tune it, your speedo might say 55 when you're really going 45. So if you get into the throttle (like to pass someone), your trans will think it has to downshift to pick up speed since it thinks you're going 55. But since you're actually going 45 you'd probably be okay staying in the gear you're in, but when the trans downshifts it might grenade.

Also, it could be that when you're going 60 and your rpms are at 2500 rpm the trans will be "confused" on why the rpms are so high at that speed with such a low throttle position. Then it'll be like "WTF you should be going 70 at those RPMs! I don't know what to do, ahhhhhhh!" and then it starts breaking ****
 

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bahahahahah^^^^^

good explanation.
sounds about what i was thinking, but couldnt put into words. :lmao
 

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Discussion Starter #30
:no

With the auto trans tuning issues aside, you won't be "wasting" your money on gears if you don't get a tune.

This is more for the manual crowd, but don't be scared from getting gears if you don't have a tune or tuner. You're not going to be slower in the 1/8 or 1/4 mile by putting in steeper-than-stock gears. I'm guessing the reason this guys wife's car is slower because they went from a performance tune to a stock tune.
She was running slower or just about the same her personal best stock with drag radials is 8.92 her best with gears and same tires is 8.96. Now that the tune is back in it it feels like it gained 50 hp but I know it's got to due with the cai and the different shift points and she has over 60 passes so she knows what she is doing
 

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Your entire first post is completely misleading. The entire time you're basically telling people that you went to 4.10s and now your car runs .2 slower in the 1/8th


MY WIFE TOOK HER 07 TO THE TRACK WITH THE NEW 410'S WHILE HER TUNER IS BEING UNLOCKED ( SEE PREVIOUS THREAD FOR WHY ITS LOCKED:mad:). HER BEST TIME WAS 9.17. SHE WAS RUNNING 8.9-9.02 WITH STOCK GEARS.
You forget to mention the little tidbit where it states you had a performance tune on the car before, and now you're running a stock tune. The slower times are a result of the change in tunes, not the change in gears.


SHE SAID THAT IT DOES NOT GET GOING TILL THE END OF THE TRACK.
Unless you're just spinning through the first couple of gears, you should take off from the line a lot better with a steeper gear. Once again, the reason the car didn't get going until the end of the track was because of the change in the tune.


I just want to make sure that noobies and whoever else is reading along doesn't get turned off of steep gears because of this thread.
 

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Discussion Starter #33 (Edited)
Your entire first post is completely misleading. The entire time you're basically telling people that you went to 4.10s and now your car runs .2 slower in the 1/8th




You forget to mention the little tidbit where it states you had a performance tune on the car before, and now you're running a stock tune. The slower times are a result of the change in tunes, not the change in gears.CASPER IS RIGHT it messes everything up on an auto. my car which is a 5 speed no tune i have no problems. I promise i am not misleading anyone




Unless you're just spinning through the first couple of gears, you should take off from the line a lot better with a steeper gear. Once again, the reason the car didn't get going until the end of the track was because of the change in the tune.


I just want to make sure that noobies and whoever else is reading along doesn't get turned off of steep gears because of this thread.
NO, im not misleading anyone --with 410s and no tune it ran a best of 8.96. the tuner was locked when the dealer flashed it. we got it back ck engine light was on and speedo was off. with completly stock it ran a best 8.92 this car has not gone down the track with the tune.
 

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Also, it could be that when you're going 60 and your rpms are at 2500 rpm the trans will be "confused" on why the rpms are so high at that speed with such a low throttle position. Then it'll be like "WTF you should be going 70 at those RPMs! I don't know what to do, ahhhhhhh!" and then it starts breaking ****
The first part would just grenade because of extra shifts. I wouldn't really say that's due so much to the gears as just too much use.

The part of the quote I left it what I initially thought. But lets say you go from the stock gears (something like 3.27 or whatever) to 4.10s; not tuned.

With stock gears, lets say you're spinning 2000 rpms at 70 mph. But when you switch to 4.10s, lets say you're spinning 2600 rpms at 70 mph. Now the initial assumption is that the tranny would wonder why it's spinning 2600 rpms at 70 mph. But since it's NOT tuned, it will actually think it's spinning 2600 rpms at 80 mph (since the speedo hasn't been corrected) and everything is normal.

The way I see it, all the inputs are still the same. The only difference is the final speed of the wheels. But I think I'm missing something b/c I don't know a ton about tranny's and Casper does. :confused:
 

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I'd like to hear a better answer than "a bunch of magic happens" and "you'll blow your tranny"

The speedo is an output from the transmission, that's why you need to recalibrate it with the tuner.

I asked BANMA this very question, hopefully they will reply.
 

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This is to SonicBoom, and I'm just spitballing. If I'm completely off base I'm not going to be sad.

I would assume it's bad for the transmission to take in your rpm, throttle position, load, etc. into consideration and then make it's calculations based on a vehicle speed that is different from the actual speed the vehicle is going.

This is a stretch, and I doubt if my numbers will be right but it's just an example. If you put in gears and don't tune it, your speedo might say 55 when you're really going 45. So if you get into the throttle (like to pass someone), your trans will think it has to downshift to pick up speed since it thinks you're going 55. But since you're actually going 45 you'd probably be okay staying in the gear you're in, but when the trans downshifts it might grenade.

Also, it could be that when you're going 60 and your rpms are at 2500 rpm the trans will be "confused" on why the rpms are so high at that speed with such a low throttle position. Then it'll be like "WTF you should be going 70 at those RPMs! I don't know what to do, ahhhhhhh!" and then it starts breaking ****
this is pretty much on the right track.

the trans opperates of the tps, ect, tct, precieved speed (where the gear/no tune problem is the greatest), line pressure, etc.

when you change gears, it throws off the precieved speed & the trans can't figure out how to shift propperly..

the whole tune thing is being blown out of proportion though, I guess a better way to say it would be the speedo needs recalibrated with an auto that has gears.
 

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MM elder
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I'd like to hear a better answer than "a bunch of magic happens" and "you'll blow your tranny"

The speedo is an output from the transmission, that's why you need to recalibrate it with the tuner.

I asked BANMA this very question, hopefully they will reply.
the reason I try to keep things as simple as possible is because very few people understand how an electronic automatic transmission works.

since you seem to know so much about them, mabie you should explain to these guys how they work.
 

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Funny ****. I take my SCT and change the gears and the tire ht and the beast runs hard.
These 05+ autos are touchy. If you understand how the tranny works. Shift point is MPH, with the od off it goes up to a higher mph to give you higher rpms. If you change the ratio of your rear gears the program might not shift with the proper line pressure and at the right time and will not do the job right....boom
Small changes like a 1/2 inch shorter tire wont hurt much but if you go from a stock ratio to the 4.10s it will be quite the jump.

Read the shift point road test in the Service Manual, Throttle Position is pointed out as is Overdrive Position ‘‘D’’, Axle Ratio and Shift Speed in mph. If you upset the balance of any of these your car will not perform as it was designed and it will fail.

Do the test with the OD off and the car acts differently than it will in "OD" If your going to do work on a 05+ auto gt you best be sure to get someone whom is in the know....Like Casper. The car shifts when the program (set values are correct) tells it to. With the sct you can go up in mph shift point and you can go down mph (WOT) if your tps is not reading WOT your car will not shift like it is supposed to at WOT and will shift early and the car will be slower. When you do a mod and flash the computer re cal the peddle and look to make sure the throttle plates are at WOT. If they are not do it until it does go to WOT and if that dont work call your tuner.
If your throttle goes past WOT get it corrected.
Protect your investment and don't mod and replace after you screw the pooch...unless you have the means to support stupidity or like living on that edge or are a racer knowing the risks. Don't change the settings on your tune you get from your tuner until AFTER you talk to them.:mad:
 

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Discussion Starter #40
Darwin that was well said. Thanks Casper and u guys for the info like I said we put the tune back in and we got lucky no damge that I know of. Can't wait to get my wife to the track with it. Im hoping she will run 8.75 or better
 
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