drive or over-drive
- Thread starter Gr33n
- Start date
QUICK STORM
B.A.M.F. BMW Tech
Re: drive or over-drive
search ownz joo. everyone has a different opinion on the matter.
search ownz joo. everyone has a different opinion on the matter.
Black Knight
I Glow Therefore I am
Re: drive or over-drive
Hey John I thought you told me not to even worry about shifting into OD unless you were trapping 115+ mph? Did I misinterpret what you were saying?
Hey John I thought you told me not to even worry about shifting into OD unless you were trapping 115+ mph? Did I misinterpret what you were saying?
blk00z28
Forced to by choice
Re: drive or over-drive
I remember someone stating that as well. Not sure if that mph is correct or if Waller was the one that said it.. But I remember none the less.
How hard was it to search for this.. Type in "Boost Launching" and holy shit.. what do you know.. http://www.syty.net/forums/showthread.php?t=29049&highlight=launching
Black Knight said:
I remember someone stating that as well. Not sure if that mph is correct or if Waller was the one that said it.. But I remember none the less.
How hard was it to search for this.. Type in "Boost Launching" and holy shit.. what do you know.. http://www.syty.net/forums/showthread.php?t=29049&highlight=launching
turbodig
Active member
Re: drive or over-drive
Easier way to interpret...
Watch your tach. Start in D, shift to OD when your tach says about 48-4900 (stock stuff).
If that happens after the traps, it isn't helping you.
Cammed/Heads motor will be different.
I shift 2-D-OD, but that has to do more with where/how my TCC locks up. (Function of the governor calibration)
Later,
blk00z28 said:
Easier way to interpret...
Watch your tach. Start in D, shift to OD when your tach says about 48-4900 (stock stuff).
If that happens after the traps, it isn't helping you.
Cammed/Heads motor will be different.
I shift 2-D-OD, but that has to do more with where/how my TCC locks up. (Function of the governor calibration)
Later,
jwaller
Evil Genius/SyTy Guru
Re: drive or over-drive
that is correct. leave it in D until you "need" OD. leaving the trans in D will engauge the overrun clutches and help hold the back side of the forward sprag. when you run out of RPM's in D (about 115mph) then bump it into OD.
Black Knight said:
that is correct. leave it in D until you "need" OD. leaving the trans in D will engauge the overrun clutches and help hold the back side of the forward sprag. when you run out of RPM's in D (about 115mph) then bump it into OD.
jwaller
Evil Genius/SyTy Guru
Re: drive or over-drive
dunno( I do shift around 7000rpms though). I dont have a speedo and fast doesnt log mph. suffice it to say the rpm you shift at will depend on your build(head and cam combo). so, when you run out of power whatever rpm that may be you need to shift. is that simple enough?
It's just a six said:
dunno( I do shift around 7000rpms though). I dont have a speedo and fast doesnt log mph. suffice it to say the rpm you shift at will depend on your build(head and cam combo). so, when you run out of power whatever rpm that may be you need to shift. is that simple enough?
Black Knight
I Glow Therefore I am
Re: drive or over-drive
By him do mean me?? If so mine is nothing compared to John's. He was simply telling me how to race the truck when you are in near stock form, you shouldn't even need OD. We were saying you don't need another gear till about 115mph.
By him do mean me?? If so mine is nothing compared to John's. He was simply telling me how to race the truck when you are in near stock form, you shouldn't even need OD. We were saying you don't need another gear till about 115mph.
George Blake
DONATING MEMBER
Re: drive or over-drive
I agree, start in Drive or Manual 2nd. Line pressure is boosted in manual second, shift to Drive once you've met the limit of your powerband. Manual 2nd and D will engage the overrun clutches. That's one benefit, the other is that you are in a 1 to 1 ratio. So your converter is locked up, your output shaft is spinning at the same rpm as the engine, and your engine stays loaded. This makes the turbo happy. Shifting to OD is completely dependent upon what your engine needs. Try to AVOID shifting from OD down to D. You do this and you go from the forward sprag being overrun to a full load 1:1 and at the same time engage the overruns. Don't use the trans to slow you down. Upgrade the brakes if you need that. :2cents:
In the 4L80e, it's the same. I've been told by two different owners now that when the 4L80e hits OD, it feels like you hit a nitrous button. Both used the exact same description so upshift to OD on the 80e is a go as well.
I agree, start in Drive or Manual 2nd. Line pressure is boosted in manual second, shift to Drive once you've met the limit of your powerband. Manual 2nd and D will engage the overrun clutches. That's one benefit, the other is that you are in a 1 to 1 ratio. So your converter is locked up, your output shaft is spinning at the same rpm as the engine, and your engine stays loaded. This makes the turbo happy. Shifting to OD is completely dependent upon what your engine needs. Try to AVOID shifting from OD down to D. You do this and you go from the forward sprag being overrun to a full load 1:1 and at the same time engage the overruns. Don't use the trans to slow you down. Upgrade the brakes if you need that. :2cents:
In the 4L80e, it's the same. I've been told by two different owners now that when the 4L80e hits OD, it feels like you hit a nitrous button. Both used the exact same description so upshift to OD on the 80e is a go as well.
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JSM
Active member
Re: drive or over-drive
Stock turbo motors don't like to spin hard. Peak torque is ~3600 rpm. Theory is shift 110% of peak.
I have found on Jeremy's the sooner we shift the faster the truck goes. We are shifting into OD at 80mph, rpm drops down to ~3200 rpm and it feels like a rocket just lite under the seat. Now this is NOT truck for bigger turbo's etc. Found out your own torque curve and play. That is part of tuning.
Stock turbo motors don't like to spin hard. Peak torque is ~3600 rpm. Theory is shift 110% of peak.
I have found on Jeremy's the sooner we shift the faster the truck goes. We are shifting into OD at 80mph, rpm drops down to ~3200 rpm and it feels like a rocket just lite under the seat. Now this is NOT truck for bigger turbo's etc. Found out your own torque curve and play. That is part of tuning.
ghettosled
SYTY SUPERSTORE
Re: drive or over-drive
when my Ty was stock motor'd it went the fastest keeping it in "D" all the way down and the trap speeds were 111mph @ 4900-5000 rpm. If i shifted into OD prior to the finish line it slowed down.
when my Ty was stock motor'd it went the fastest keeping it in "D" all the way down and the trap speeds were 111mph @ 4900-5000 rpm. If i shifted into OD prior to the finish line it slowed down.
wantingasy
Active member
Re: drive or over-drive
I think I would have had a heart attack if I didnt' shift into OD at 4900 rpm!!!
ghettosled said:
I think I would have had a heart attack if I didnt' shift into OD at 4900 rpm!!!
ghettosled
SYTY SUPERSTORE
Re: drive or over-drive
it pulls a little different with a larger turbo.. TE45 at the time. now my motor just starts to come alive at 4900
it pulls a little different with a larger turbo.. TE45 at the time. now my motor just starts to come alive at 4900
jbone
Member
Re: drive or over-drive
:hijack:
sorry but I have to throw in a question of my own: When racing from a roll (stock motor/tranny) what gear do you choose? Do you leave it in D or OD and let the tranny do the shifting or do you put in 2nd??
( Disclaimer: I am a firm believer that racing from a roll is gay. Nevertheless, some people think they have a better chance from a roll against the ty and I like to prove them wrong. :lol: )
:hijack:
sorry but I have to throw in a question of my own: When racing from a roll (stock motor/tranny) what gear do you choose? Do you leave it in D or OD and let the tranny do the shifting or do you put in 2nd??
( Disclaimer: I am a firm believer that racing from a roll is gay. Nevertheless, some people think they have a better chance from a roll against the ty and I like to prove them wrong. :lol: )
wantingasy
Active member
Re: drive or over-drive
If I'm going 50mph or slower I keep it in D. Over 50 I'm in OD so it kicks down pretty hard. I try not to race from a roll though, possibly because I'm overboosting right now :tdown:
If I'm going 50mph or slower I keep it in D. Over 50 I'm in OD so it kicks down pretty hard. I try not to race from a roll though, possibly because I'm overboosting right now :tdown:
93TyphoonPacetruck
Member
Re: drive or over-drive
defnately D, I don't trust the OD, I used to shift into 2 all the time, then to D, but I just leave it in D and let it downshift itself. Hope the TY is coming along good Jay :tup: my SY needs a new front right axel :rant:
defnately D, I don't trust the OD, I used to shift into 2 all the time, then to D, but I just leave it in D and let it downshift itself. Hope the TY is coming along good Jay :tup: my SY needs a new front right axel :rant: