modern yanks and unpredicable kickdown?

modern yanks and unpredicable kickdown?

Author
Discussion

steveo3002

Original Poster:

10,637 posts

179 months

Thursday 13th January 2011
quotequote all
i dont own a yank , but have rented them over the years on holidays and keep promising i will buy one

was talking to a friend and we both agreed that you could get kickdown when not expected , for instance bend uphill , need to go 5mph faster and put foot down then it kicks down 2 gears and redlines it

is there a way to press on safley? whats the procedure for wet corners and such?

maudyZ28

133 posts

185 months

Thursday 13th January 2011
quotequote all
well it's not unpredicable, its more unexpected. I know at lest on my gen 4 camaro that all shifts are based upon (other than at WOT) are Speed and throttle position. EFIlive allows you to tune these and see the respective graphs for up and down changes. The more throttle you apply the faster the car will go before an up shift.

As for the down shift it is set at a lower speed than the upshift parameter for a give throttle position. Say upshift 1->2 at 50% throttle is 35mph then you have to drop below say 30 mph for a down shift at the same throttle position 2->1. A very small press on the gas of a few % will be sufficient to move a higher downshift speed. ie press to 55% might mean a down shift below 36 mph, so the car will shift back down.

You just need to be careful not to be too irratic on the throttle in bad conditions. You can easily force the car to upshift by lifting the throttle, but for a downshift you cannot just mash it for a down shift and expect to leave it there without it to rev up.

MoonMonkey

2,219 posts

218 months

Thursday 13th January 2011
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Can't say I've ever really noticed. The kickdown on mine can be a bit annoying when you want to press on, mash the pedal and nothing happens as quickly as I would like but that's partly made better by disengaging the overdrive.

Roo

11,503 posts

212 months

Thursday 13th January 2011
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Haven't noticed it as being different to any other automatic I've driven.

Roo

11,503 posts

212 months

Thursday 13th January 2011
quotequote all
Haven't noticed it as being different to any other automatic I've driven.

LuS1fer

41,495 posts

250 months

Thursday 13th January 2011
quotequote all
You have to be pretty emphatic to get a GM box to kick down, most of the time you're trying to get it not to change up. never had a problem in all my years driving one and there is a kickdown cable which i think is adjustable anyway on older cars that aren't all electronic.

shovelheadrob

1,564 posts

176 months

Thursday 13th January 2011
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When I first bought my current F150 I found the kickdown a bit sensitive, but now I am used to it I find it pretty predictable 99% of the time. Just don't lift off the throttle completely & it will stay in the same gear if you accelerate gently, lift off then accelerate gently or hard & it will kick down. Alternatively if you just want to maintain a constant speed, use the cruise control.

Trooper2

6,676 posts

236 months

Wednesday 19th January 2011
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If you want unpredictable (or shall I say sensative kick down) try an early 2000s Disco II with a ZF autobox in "sport mode". biggrin

dblack1

230 posts

166 months

Thursday 20th January 2011
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Ive owned a few GM vehicles with both electronic and non-electronic automatics. on the newer electronics, if you floor it, it will drop down to the lowest acceptable gear for that speed, the key, dont floor it unless you want that big change. Some of the older electronic transmissions (like the 4t60) had a wire that controlled shift sensitivity, some cars had a Performance/Economy shift mode that you could switch, but cars equipped with the same trans but no sensitivity selection still had this wire.

I rented a v6 mustang once, and it liked to downshift even under light throttle, it was fairly ridiculous, but after driving it for a day it was predictable enough i knew what to expect.

mrobin33

930 posts

229 months

Saturday 29th January 2011
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I have a 2010 Camaro SS with the six speed auto and I find it a bit irritating - especially the low first gear and the fact it changes down to first at low speeds - makes it jerky. Also note it changes down sometimes when it's unnecessary - the engine has so much torque it'd be better to slug it out in my view. Very different from the older four speed GM boxes - seems the fashion for six speeders with paddles is driving them to be programmed to be more 'sporty' which ends up being frenetic. Will get a manual Z28 in 2012...

ecuboss

45 posts

178 months

Sunday 30th January 2011
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mrobin33 said:
I have a 2010 Camaro SS with the six speed auto and I find it a bit irritating - especially the low first gear and the fact it changes down to first at low speeds - makes it jerky. Also note it changes down sometimes when it's unnecessary - the engine has so much torque it'd be better to slug it out in my view. Very different from the older four speed GM boxes - seems the fashion for six speeders with paddles is driving them to be programmed to be more 'sporty' which ends up being frenetic. Will get a manual Z28 in 2012...
Thats the same setup as the VXR8. Many people including myself have remapped them with very good results.

PonchoJ

11 posts

196 months

Monday 31st January 2011
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Never noticed a problem on the yank cars. I've always got annoyed with the German auto gearboxes. I had an A6 as a daily and that was typical of them....wrong gears up hills, not dropping a gear without bootloads of throttle. It's like an economy configuration that forgets what it's doing half the time.

When an engine with 20 valves is coupled to an auto box, the auto has to be pretty special at its job.

I sold the daft thing in the end. lol


That doesn't answer your question does it. haha, sorry.