Bottom transmission number effect?

  • Thread starter Thread starter ripcurl
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ripcurl

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ripcurlgti
I have been tuning for awhile now but never truly understood how the bottom mph number(not the graph) affects how the car runs.

I tune for 3k, so from the beginning the bottom mph number is usually at the lowest because that seems to be the setting to get the longest 1st gear.

But I don't always have to do that for lower hp cars or AWD cars that don't need that long a 1st gear.

Not sure how if the effect is the same on 1/4 as it is on 3k/tunnel?
 
transmission tuning usually has 3 base numbers to go off by.
1. mph by the graph
2. final number
3. mph below the final number
 
You're talking about the top speed slider? From what I've come to understand, it's just a ballpark on what the top speed will be without changing the final ratio. The only reason we slide the final gear is to compensate for space between the gearing that would create shift lag.

For example, having an Indy tune for a 10 sec car would be ~140 at the shadow, 150-155 on the top right mph(give or take). You can set it that way with the bottom MPH at 150-160, with stock final gear; or at the lowest mph and slide the final to the left. The difference is the way the gear ratios relate to one another. They will be the same spacing throughout all gears with stock final gear & mid-range top speed slider, or wider in the first few and tighter in the back-end when stretched with lowest top speed.

Can't use any real-life scenario to describe it more clearly because you can't stretch gears in real life; but you'd still match up transmission gears to rear-end to make your car top-out on whatever finish line you're tuning for, whether it be 1/8, 1/4, or 1/2 mile.
 
I have actually never used any other top speed setting other than the lowest. When 1/4 mile tuning. If I didnt get the desired top speed I would move the final gear higher then reselect the lowest mph setting and try again. I have begin to tune for tunnel (1 mile or more). Gotta find a room that doesnt contain slipstreaming noobies who havent figured out the tuning methods and are determined to make themselves look like idgets. Anyhoo, I recently tuned a Subi for the tunnel and it was bogging, even after having 1st gear set to far right. I decided to try a diffrent top speed, instead of 112mph I chose to start at 168mph and then lowered my final gear from 5.000. While I still had the 201mph top speed my 1st gear ended up closer to the left side of the graph which eliminated my bog and made for an intresting learning experience for me.
 
I think I have seen you in the tunnel before.

The number in the bottom may effect low end, mid range or top end, just not sure how or if its true?

A lot of the lower hp cars or awd, if i flip the transmission using the lowest mph(slider) 1st gear ends up too long, even if its maxed out short, its still too long(bogs) so i tend to use a higher mph(slider)
 
ripcurl
I think I have seen you in the tunnel before.

The number in the bottom may effect low end, mid range or top end, just not sure how or if its true?

A lot of the lower hp cars or awd, if i flip the transmission using the lowest mph(slider) 1st gear ends up too long, even if its maxed out short, its still too long(bogs) so i tend to use a higher mph(slider)
Click to expand...

Exactly what I think. Maybe it will help using this method even for 1/4 mile cars that you have to set 2-6 gears to far right for. S2000 being one that comes to mind. (Before you noobs tell me the S2000 has 7 gears or if you launch in 1st your doing it wrong) I am reffering to the actuall Honda S2000 not the Amuse. Remember those of us that have been tuning and became sucessful at it decided to tune slower cars too, because its fun.
 
ripcurl
I think I have seen you in the tunnel before.

The number in the bottom may effect low end, mid range or top end, just not sure how or if its true?

A lot of the lower hp cars or awd, if i flip the transmission using the lowest mph(slider) 1st gear ends up too long, even if its maxed out short, its still too long(bogs) so i tend to use a higher mph(slider)
Click to expand...

interesting, maybe this method can be used for lower hp cars that have a bog tendency in the 1/4
 

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