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Fastest launch 86.5 aut in 2nd??

 
Old 07-04-2010, 12:58 PM
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rexpontius
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Default Fastest launch 86.5 aut in 2nd??

Afer the T-belt and Porkensioner upgrade and correction of incorrect timing, my 86.5 now drives like a dream.

I noticed the car is (a lot) faster from the line when I put the gearselector in 2.

It seems when it is in D it usually takes off in 2nd gear.
I also adjusted the bowden cable to remove the slack, and noticed when it is too tight it will hold the 1st gear too long when driving normally (upshift at approx 3.000 rpm)

Is it normal behavior its faster from the line with selector in 2?

cheers
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Old 07-04-2010, 01:02 PM
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GlennD
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I am thinking something must have changed when the work was done. My 86.5 launches in first when in drive ("D"). When I put my selector in 2 it also launches in first but holds it until high revs or I manually select 3.

Glenn
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Old 07-04-2010, 01:19 PM
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rexpontius
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It is certainly not related to the t-belt change, the gearbox behaviour is the same as it was before the job, but I just did not feel confident enought to try to launch a many times with no info on the condition of the t-belt.

When would the gearbox normally upshift from 1st to 2nd ?

cheers
Michel
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Old 07-04-2010, 01:38 PM
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it starts out in 1st when the selector is in D
S4 starts out in second when in D
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Old 07-04-2010, 01:56 PM
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rexpontius
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Hmm, could it be the PO changed the gearbox with an S4 box?

I'm sure they did some work on the car removing at least the complete selector assembly and some other parts (they unfortunately did not reassemble everyting as they should, but thats sorted now).

can I check partnumbers somewhere?
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Old 07-04-2010, 02:02 PM
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Landseer
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Yes, underneath transmission there will be a number on a cross brace part of the box itself.

Post the number and we can cross-check.

S4 torque convertor is 1 inch wider in diameter, making it a tight fit in the tunnel of the earlier body.

Second gear start was a phase-in during the 87 model year. Some with it, some without.
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Old 07-04-2010, 07:14 PM
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rexpontius
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Thanks, will check the number as soon as the car is on a lift again.

Took it for a drive this afternoon and after carefully warming it up, I checked again just to make sure.

When it is in D and I "floor it" from standstill it will shift up to the next gear well over 65 mph, so it seems to me that must be 2nd gear.

With the selector in 2, it will get off the line signficantly quicker,even with some tire screeching, and upshift around 70 or 80 km/h and approx 5500 rpms), so unless I am really imagining things, this means it takes off in 1st gear.

With normal driving (in D), the car never feels slow, has plenty of torque and shifts quite nicely up and down the gears. (sometimes at lower speeds still a bit clunky, but surely acceptable and I quess I cannot compare it to a modern car)

Does this behavior seems similar to S4 behaviour (at least the ones which are supposed to take off in 2nd)?

Cheers
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Old 07-04-2010, 07:40 PM
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I have an 89 gearbox. It starts in second unless given >3/4 throttle. If it gets that kind of throttle, it starts in first.

If it I don't give that much throttle pulling out, but then floor it, it will downshift into first.

All the above is with selector in D.
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Old 07-07-2010, 06:06 PM
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Spent some more time driving the car around, drives perfect, but I just cannot get it to use the 1st gear with the selector in D.

Also with the bowden cable very tight it will never use 1st gear.

I am not really familiar with automatic gearboxes, but perhaps there are some auto gearbox guru's who can tell me what makes the gearbox choose what gear from takeoff??

With the selector in 2, as decribed above, the car will still take off in 2nd when driving off with little throttle, and it will use 1st gear with approx >50% throttle.

When accelerating flat out it will upshift from 1st to 2nd gear earlier in the revs (at approx 5500 rpm I think) than in other gears (in other gear it pulls until approx 6500 rpms). Is this normal behaviour?

Cheers
Michel
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Old 07-07-2010, 07:21 PM
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Mine do the last part, upshift 1 to 2 where you said, and third at redline, not sure of rest.
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Old 07-07-2010, 07:35 PM
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taffelman
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Originally Posted by rexpontius View Post
Spent some more time driving the car around, drives perfect, but I just cannot get it to use the 1st gear with the selector in D.

Also with the bowden cable very tight it will never use 1st gear.

I am not really familiar with automatic gearboxes, but perhaps there are some auto gearbox guru's who can tell me what makes the gearbox choose what gear from takeoff??

With the selector in 2, as decribed above, the car will still take off in 2nd when driving off with little throttle, and it will use 1st gear with approx >50% throttle.

When accelerating flat out it will upshift from 1st to 2nd gear earlier in the revs (at approx 5500 rpm I think) than in other gears (in other gear it pulls until approx 6500 rpms). Is this normal behaviour?

Cheers
Michel
This is exactly how the S4 box works.
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Old 07-07-2010, 10:41 PM
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Originally Posted by Landseer View Post
Yes, underneath transmission there will be a number on a cross brace part of the box itself.

Post the number and we can cross-check.

S4 torque convertor is 1 inch wider in diameter, making it a tight fit in the tunnel of the earlier body.
<snip>
I think the 86.5 is the same belly pan as the S4, so the S4 TC should fit the same.
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Old 07-07-2010, 11:47 PM
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86.5 is same body as 86/5/4. S4 TC will fit, but its very tight.

But on heavy throttle the S4 also goes to first in D.

2nd gear start wasn't introduced until Spring 87 production, maybe for some late 87 S4-S, but for the 88 model year particularly, and it still starts in first anyway when D is selected during heavy throttle.



So the question is really one for Steve Cataneo -- why does this man's 86.5 not propel the car in 1st gear from the line when floored in D?

Last edited by Landseer; 07-08-2010 at 12:05 AM.
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Old 07-08-2010, 12:22 AM
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The underbody has the same part numbers '86.5-'89: left 928 501 953 04/right 928 501 954 04

Attachment points for the aluminum trailing arm mounts, raised rear seat bottoms, rerouted fuel lines, etc. - all to fit the dual exhaust and giant 86.5/GTS resonators.



That said, I don't know for sure if the TC hump was changed until '87, but I'm guessing it was part of the package.
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Old 07-08-2010, 12:45 AM
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Rear seats were supposedly changed in S4 to match tunnel.

Transmission should still start in first, 86, 86.5 or 87.
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