3 Speed Automatic vs 8 Speed Automatic

[Michael_]

Hi,

Past Weekend i and a friend rented a 2017 Dodge Challenger SRT-8 with about 500hp and the 8 Speed Automatic. I was pretty impressed by its performance on our german autobahn (i live in germany).
You always have power even if you drive already 120mph this thing still pushes forward real quick if you hit the pedal. Also handles and stops very well.
Yeah if new car than mopar or no car i guess.

But to my question, i am actually saving to buy a 1969 Dodge Charger with a 440 and 727 3 Speed Automatic. want something with 500 or 600hp (either buy something thats already built or get it built.)

So i was pretty impressed by the 500hp in the 2017 challenger but i am now wondering how much credit the 8 speed automatic has in the whole performance of the car.
I also think the 727 will shift way slower?

Can you compensate the lack of the modern transmission/technology by adding more HP? and if so how much?

Kind Regards,
Michael

 

[Cranky]

The Hellcat Redeye has nearly 800 horse power and comes with the 8 speed....but not sure if it's the same trans or not. You can add a Gear Vendor's overdrive to the car with the 3 speed and it'll take the 500 hp easily.

 

[steve340]

A car will only go as fast as the gearing allows it go.
More horsepower accelerates the car to that point quicker.
Extending the rev range of the engine allows you to go faster.
That is why the modern transmissions are so good, they allow you to in effect change the gearing.
If you are buying a transmission I would not get a 727 but if you are old school get a 4 speed one with overdrive 4 TH gear.
Silver Sport Transmissions do a kit that looks good.

 

[Hey-O]

It's no secret the more gears you have the easier it is to keep the engine in that sweet spot that the car pulls better at. Drag car with major HP pull a two speed transmission and with that much HP that many gears are not needed. I had a car with around 525 HP and a three speed transmission and it pulled great, but, it was terrible on the highway. Living in Germany and being able to drive at higher speeds, you will get sick of listening to the engine scream at higher speeds. If it's 500 to 600 HP you would like to have, you could get by with a highway gear and a Gear Vendor overdrive. I had one and it's about 3000 dollars and as Cranky said it will handle up to around 1500 HP and never break. So, with a 727 3 Speed Automatic, which is cheap to replace or repair, compared to these new 8 or 10 speed transmissions and a GV overdrive that you will never break, which is about a 23 % overdrive, you should be able to have the best of both worlds!

 

[Michael_]

Maybe i can get the chance to drive a Stock 68/69 Charger with the 440 and 727 to see how it compares (acceleration).

But driving fast on the Autobahn isnt the only thing i want to do. this car will be my daily driver. So shouldnt be a dog in the city etc.
So Highway Gear / Overdrive still a good idea or no way around adapting the 8 speed from the new challenger?

Well more HP is always better but if it performs like the new Challenger SRT-8 im fine with 500-600 definitely.

PS:
Im a fan of the old technology also so i do not really want things like computers, injection etc. in the car if not needed.

 

[steve340]

The 8 speed would definitely be computer controlled.
The Gear Vendors unit or an overdrive auto sounds right for you.

 

[Dipstick]

It's no secret the more gears you have the easier it is to keep the engine in that sweet spot that the car pulls better at.

Yep, ask any trucker.

 

[Michael_]

The 8 speed would definitely be computer controlled.
The Gear Vendors unit or an overdrive auto sounds right for you.

Yeah i know but at least only the Transmission and not the Engine would be computer controlled.
I want to avoid if possible but performance comes first of course. But it seems i do not need it anyway.

Thanks for all your replys.

 

[Bobby Sixkiller]

3.23 gears and a gear vendor would be great.

 

[Michael_]

Also did a little research it seems that nobody was able to get the new 8 speed to work in a old car and an old Engine. Seems that there is no Controller available.
So you would have to adapt also the Engine and Dash and all that, i wouldnt do and want that.

But i guess i will go for the GV Unit anyway.

 

[Hey-O]

Also did a little research it seems that nobody was able to get the new 8 speed to work in a old car and an old Engine. Seems that there is no Controller available.
So you would have to adapt also the Engine and Dash and all that, i wouldnt do and want that.

But i guess i will go for the GV Unit anyway.

I thought so.

 

[Hey-O]

Hallo, ich heiße Ulli. Ich bin in Deutschland geboren. Sie werden es hier mögen, viele talentierte Leute.