45 mph in first gear....01 grand am

[john_V63400]

ok so i started to tun my car and i changed my shift points and highered my rev limited. I extended my 1st gear to 45 mph. Is that a safe speed. If not what is. And im allso reving at 6400 in first gear so what mph should i match with it. Cause i noticed when i just changed the rpm the engine just hung at the speed and reved up. So i realize i must chage both mph and rpm. What is usually a good rule for rpm to mph change?

[Fedaykin]

If you adjust the RPM on the engine you have to remember to adjust the MPH on the transmission accordingly, otherwise you will just rev without going anywhere. To adjust your MPH you need to have a buddy drive at the RPM you want in first gear, while you hang on from underneath and adjust the largest bolt on the transmission, try turning it clockwise. You need to do this while you're driving for each gear you want to adjust RPM and MPH.




seriously, what is this guy talking about?

[SappySE107]

I dont know how its going to rev the motor but not gain MPH without toasting your transmission from all the heat. I have no idea what the RPM setting does but its at 6000 on OBD1 when you can go to whatever MPH was listed regardless of RPM limits (other than rev limiter in gear or P/N).

Unless you made something worse than stock, it will rev to 7000 and not blow the bottom end. I have no idea when your valvetrain floats or it starts to drop power.

[john_V63400]

I am not floating at 7000 but i seem to loose momentem that high so im looking at 6500 rpm ? My question is if i set my tranny to shift at 45 mph will it be safe. Will it nor blow my tranny instantly. Does anyone else have there tranny set to shift that high.

[SappySE107]

Im sure the transmission won't like 7000 RPM too often but I couldn't tell you what MPH you need to set it to vs RPM.

[john_V63400]

so you do need to adjust the first gear mph as I raise the rpm limit ? Its just not raise rpm and that's it.

[SappySE107]

I don't know. On OBD1 you leave the RPM limiter vs gear alone cause it doesn't do anything. I only change the shift points vs MPH, and the rev limiter if the RPM will be higher than the limiter at the mph set for shifts.

[john_V63400]

I guess my question is now is can my tranny go 45 safely in first gear with no reprecutions if my engine can handle the rpm's safely??
01 grand am gt

[strtrydr]

i get 40mph in "1' on my 3400 alero but that is almost bouncing off the limiter

[john_V63400]

I have already been 47 mph in first, but is is safe on the tranny, i can handle the RPM

[SappySE107]

The trans doesn't care what MPH it is.

[john_V63400]

So 47 mph in first is relatively safe? That is my main question. My engine rpm can handle it.

[Azrael]

The biggest question is whether or not it's beneficial to shift at that speed. If the engine RPM before/after the shift is too far from your peak power then you'll be hurting your acceleration. A dynograph is almost necessary for tuning shiftpoints.

[torq455]

my 3400 only has the FFP pulley, a cone filter, 180 stat and a pcm tune from Milzy. it shifts at 5800 1st and 2nd and that's all the higher my powerband will allow. it quits gaining at 5500, and keeps me pinned till 5800. any higher rpm i found seems slower.

are we talking about a stock 3400?

[john_V63400]

Far from stock. Beefy valve train, headers, 15 psi of s/c boost, forged pistons, cam, and the hole 9 yards. My cam seems to love high rpms. I have a apointment at the dyno next week so i will c what rpm i should shift at. But it seems like my engine starts to sore after 5500 to 6600!