Transmission gearing questions

[Naumoff]

I just made a nice trip to Carlisle. 160 miles one way. Lots of Highway driving. I kept it under 70 on the way up. On the way back I was running 80 at 3500rpm with the toplaoder close ratio and 3:31.

She was just cruising at that RPM. And I don't need to risk getting another ticket.
I still think I would prefer 3.54 or 3.77 for all around street use. I don't do much highway and my engine likes 2800rpm or better.
I wore earplugs for the long trip. I have Tendenitice(sp?) in my right ear and the cold wind slapping on my ear will make it sore after a while.
Not being able to hear the exhaust so much I was able to pay attention to the pull of the engine as I hit the gas as compared to the lumpyness of the cam with no earplugs. The engine pulled smooth and steady under light acceleration.
On another note when I was leaving Carlisle through the fairground and on my drive today. If I am trying to creep real slow I have to constantly push my clutch in and out so I can keep the speed down. The engine idle is set at 900rpm as the engine builder recommends.This is really annoying and a shorter gear would be nicer for that.

[scott h]

"tinnitis", ringing of the ears

[Slither]

paul....

you are making this waayyyyyy more complicated than it needs to be....
only 2 questions need to be answered...
1- how much freeway running will you honestly do ??
2- what rpm can you live with going down the freeway ??
not much freeway..go with a toploader...
are you honestly going to climb in the cobra and do 700 plus miles like i
did on wed and sunday ?? if so then go for the overdrive(.64).

as for gear spreads....who cares ??? you are talking about a 2400lb car
with most guys running 400+ ftlbs of torque. the drop off between gears
is not a issue. ask brent how much mine drops off from the first(3.27)
to second (2.20?) shift..not enough to even notice.

chris

This is the kind of info I was hoping to get from the gang. I suspected that gear split did not make much of a diference in these cars. I imagine that most guys could literally melt the tires off of them in the first three gears... pretty much at will.

I drive a whole lot... that said, I don't think I would be intimidated by a 350 mile (one-way) trip in a Cobra, but 700 miles might be a different story, yet...?

as for diff ratios,
3.54+bfg 295/50/15 is identical to
3.73+quick time 295/50/15
the hoosiers are roughly 2" taller.

i have driven a unique with a 408/tremec/3.31 posi,does it pull hard ??
yep...does it pull as hard as mine...nope. is it a great driving car ??
yes. all the combos will work great...just be honest about what you
intend to do with it....

chris

Yep, but all 408's are not created equal... don't know about the one you drove, but I doubt it was anything near what you are runnin' in yours, so I believe in your observation.

I can see that it is a compromise regardless of choice. If a close ratio toploader with a .68 overdrive were available then it would be a no-brainer... that and a 3.54 or 3.77 gear set would be the ticket. (And yes guys, I know that there are 5-speed racing trannies available for gobs of cash.)

You did not mention what gear set you have...

[Slither]

Chris, Brent, and anyone else that might know:

For the Windsor project, I got the Comp Cams #35-426-8 cam, which has a 2200-6200 rpm operating range for use with the stock displacement.

I am under the impression that stroking the engine out to 408 will move that power band down in the rpm range. I am curious as to how much you would expect that shift to be based on greater than 16% increase in displacement?

Thanks!

[Brent]

I do not think it will lower the powerband in direct relation to the percentage of displacement increased.
I figure it will lower the powerband 7.3285636352%
Or about 491.235858236 rpm

If you run a SW tach you will never know it anyway.

[chris knueven]

brent,

you'll just have to get very good at tapping the glass on the tach
like i do.....

chris

shifting at the miss

[Slither]

!!!!!!!!!!!!!

[Justin Upchurch]

Paul,

When in doubt always go with a larger cam............. If the tac isn't accurate just set your MSD limiter as your shift point.

Justin

[chris knueven]

justin,

see,one weekend around me and i have already corrupted ya.......

i have been reading up on some combos,i think your motor ought to
be in the 400's somewhere,maybe even around 450 rwhp. just dont be
afraid to rpm it......

chris