Topic: Auto trans shift RPM

[SKY888]

oh ok!

I think I know that table you're talking about.....I do the same thing with my manual using HPT.


I just don't know why the car of Josh (project scarab)...even when the TCM was sent to Lyndon,  its not working properly.    That's why I would like to know what's going on.

[TC-GXP]

TC-GXP.....how far are you from Bellingham/Hopedale, MA?

Probably around 45 minutes. What do you have in mind?

[Gentleman Jack]

oh ok!

I think I know that table you're talking about.....I do the same thing with my manual using HPT.

Can't you do this with your feet in a manual?  Why would you tune your shift points with HPTUNERS if you have a manual?  I'm totally confused

[SKY888]

Can't you do this with your feet in a manual?  Why would you tune your shift points with HPTUNERS if you have a manual?  I'm totally confused

GJ....I'm referring to the rev limit per gears on a manual.

so for example, the rev limit in 1st gear is only 6500rpm.....you can adjust it to be at 7000rpm.   
Same thing with the other gears, you can adjust the rpm limit reasonably.


I wont adjust the rpm limit to 7500rpm......without supporting mods such as upgraded valve springs etc.....

[SKY888]

Probably around 45 minutes. What do you have in mind?

Oh ok!

I actually live in Woonsocket, RI which is 10 mins away from Hopedale, MA where SMG motoring is located.  The shop that tunes and take care of my car.    Project Scarab also goes there for tuning his fully built engine as well.   

so if you want tuning by a reputable ECOTEC tuner......SMG is the place to be.

And maybe next year you can join the KRONUS group (kappa owners of new england) with their runs and gatherings!

[Sol Asylum]

GJ....I'm referring to the rev limit per gears on a manual.

so for example, the rev limit in 1st gear is only 6500rpm.....you can adjust it to be at 7000rpm.   
Same thing with the other gears, you can adjust the rpm limit reasonably.


I wont adjust the rpm limit to 7500rpm......without supporting mods such as upgraded valve springs etc.....

So how does the ECM know what gear you are in with the manual?  I don't recall there being some sort of sensor to tell what gear the trans is in for the manuals, maybe I am wrong.

How does that work anyway when you are between shifts which has been the case the few times I have had the rev limiter kick in, missed a shift but stomped the gas and guess what?

[SKY888]

ON HPT software

Under  "fuel cut-off RPM vs Gear" table

                       RPM Limit
Park/Neutral     6500
1st Gear           7400
2nd Gear           7400
3rd Gear           7400
4th Gear           7400
5th Gear           7400
Reverse            6500

[Sol Asylum]

That's fine but if there is no way for the car to know what gear the trans is in how does that work?

[Gentleman Jack]

888,

Totally understand rev limiter.  I was totally confused how you tuned the shift points

Must be a sensor to tell the car what gear?  It certainly knows when it is in reverse

[DaveOC]

That's fine but if there is no way for the car to know what gear the trans is in how does that work?

If the ECM/BCM knows how fast you're going and the RPM, it has a very good idea of which gear you are using.

[Sol Asylum]

888,

Totally understand rev limiter.  I was totally confused how you tuned the shift points

Must be a sensor to tell the car what gear?  It certainly knows when it is in reverse

Reverse sensing is usually a switch that the gear lever actuates when in reverse so as to turn on the back up lights.

[TC-GXP]

Haven't got it to the dealer yet but I floored it today and it went to 6500 and started faltering like it was shutting off the fuel or pulling timing out or something. I guess that's the engine shut off protocol in the ECM keeping it safe. Interestingly enough it appears to do it pretty much only on the first full throttle run of the day. I floored it again later and it shifted at 6000 RPM like most other times. Weird. I need to call the dealer after Christmas I guess.

[tazz]

With the GMPP tune fuel cuts off at 6500 and it will stumble and boost will drop to zero for a fraction of a second.  Try a roll from 20-22 and floor it with TC turned off you will hit the Rev limiter and it will stumble and boost will drop to 0 then it will pick back up again.
Depending on the condition at least with an Auto it may or may not shift at 6500 and may shift at a lower RMP even at WOT.  A roll from about 18-22 and flooring it will make you hit rev limiter and the conditions you described.
I raised mine to 7000 and now it never hits the limiter and stumbles like that and if it does it's very minimal and shifts smoothly.

[TC-GXP]

Other than the occasional over revving in 1st gear it usually shifts around 6000 RPM so I'm typically under the rev limiter for the most part. I've never noticed any difference whether it was in Competitive Mode or not but I'll pay attention to that next time I drive it. My biggest worry is the dealer will not be able to duplicate it and will give the car back to me as it is after beating the crap out of it all day. As a mechanic I understand if they can't see it they can't fix it but I thought the OBD2 ECM's kept a "record" inside that shows all the times you've floored it, how long it's been idling, everything. If they accessed that they'd see it had over revved a few times and try to figure out why it happened. I'll email them about it now to get them thinking about it.

[tazz]

Do you have time to take a ride with the Tech that will be working on the vehicle?  That would be the best way if you can.
If it does I don't think the dealer can "see" that info since they would begin to wonder why everything is "zeroed" out for those that upload the stock tune before they take it in for service.  Some ECM's do keep a log of sorts but it's really key cycle limited before it resets and even if it does just say you disconnected the battery at that point and that's why everything is zeroed out.