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Gear Ratio Recommendations

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66brm Seriously Crusin Dubber

140 posts · joined Nov 2009 ·

#761062
I'm in the process of finishing off a 2176cc type 1 engine that will run 8.9 compression, c45 cam, 42mm intake 37.5mm exhaust and CB fuel injection. I'm looking for some advice on having a gearbox built for it, obviously fitting a super diff etc is anticipated, but what r and p and ratio's?? Car is an oval that will be used regularly on the street, so not after a close ratio screamer, I just want to make best use of the extra power and torque.

Thanks

trickysimon 100km/h is only 9 seconds away

1,473 posts · joined Dec 2007 ·

#761076
My gearbox has:
R/P: 4.125
1st: 3.78
2nd 2.06
3rd: 1.32
4th: 0.89
Super diff and HD sidecover.
Can't recommend it highly enough. Nice short gears, nice highway rpm and strong.

66brm Seriously Crusin Dubber

140 posts · joined Nov 2009 ·

#761078
Tricky, can I ask what rpm you are doing at 100km/h and the size of your rear tyres?

trickysimon 100km/h is only 9 seconds away

1,473 posts · joined Dec 2007 ·

#761086
100km/h is at around 3100 and im running 195 65 14 (23.98 inch tall) tyres.

grogy Custom Title Time!

1,000 posts · joined Aug 2007 ·

#761096
howdy, sorry to hijack u thread a bit, just some past experience wit da c45cam. maybe it was just my setup but it ran hot until i changed cams. [i had 10to 1 comp} i didnt change the comp i actually upped it when i changed cams, and it ran cooler. hope you dont have same problem. regards grogy

trickysimon 100km/h is only 9 seconds away

1,473 posts · joined Dec 2007 ·

#761097
You probably had too much C/R for that camshaft. 10:1 seems alot for a c45.
Going off what I've read, you have to match your camshaft to your C/R.

ttriebler Officially Full-On Dubber

321 posts · joined Jan 2008 ·

#761117
What about
1st 3.454 = 51 kph at 6000
2nd 1.947 = 91 kph
3rd 1.366 = 129 kph
4th 0.972 = 182 kph
5th 0.738
Final drive 3.9
At 100 kph in 5th you're doing 2500 rpm
This gearing in a bug with 110hp motor and those tyres should get you 0 to 100kph is 7.4 sec, 1/8th mile in 9.7 sec, 1/4 mile in 15.0 sec.
Reversed gears for Subaru transmissions.
Fit a Subaru 5 speed to your rear engined car
www.subarugears.com

66brm Seriously Crusin Dubber

140 posts · joined Nov 2009 ·

#761120
And where does the fifth gear come from??, reverse wont go that fast

VWCOOL 23 Windows of Awesome

5,158 posts · joined Jun 2003 ·

#761122
66brm wrote:And where does the fifth gear come from??, reverse wont go that fast
It's the next one after fourth 😂
Pay your debts, CxxT

66brm Seriously Crusin Dubber

140 posts · joined Nov 2009 ·

#761124
If its being suggested that I cut up the back of an oval to fit a Berg5 then no, I considered it but wont be making any changes that aren't easily reversible in the future

hellbugged 48's and straight cuts

5,080 posts · joined Apr 2003 ·

#761127
Well there goes my recomendation 😁

66brm Seriously Crusin Dubber

140 posts · joined Nov 2009 ·

#761128
So lets get the topic back on track, ratio and r and p suggestions for a four speed swing axle please, will be running 15" rims with probably 195/65R-15 tyres

hellbugged 48's and straight cuts

5,080 posts · joined Apr 2003 ·

#761129
You know how much work to fit the five speed?........it is just a nick from the torsion housing and a dimple under the back seat where no one will see it anyways. Five speeds really are the best of both worlds combining close ratios with usable top gear. If your budget does allow it, i would most certainly say go that way

What "trriebler" is talking about would be the subaru 5 speed he is working on using a flipped diff.......which he says fits in the frame horns with no cutting to it

Anyways if at all possible, i would highly recomend driving the car with the engine to learn where it works and what rpm range it likes........with the EFI the bottom end will be very very smooth, allowing ratio choice perhaps with larger 'drops" than what would be the norm for the combination.

Choose your fourth gear and work back from there.

66brm Seriously Crusin Dubber

140 posts · joined Nov 2009 ·

#761131
But the added cost? can it really be justified? And when you say "just a dimple" how big?

hellbugged 48's and straight cuts

5,080 posts · joined Apr 2003 ·

#761135
I have run standard boxes and a close ratios boxes with nutbag low fourth gear........i wanted something that ran hard and fast like the close box BUT also a daily driver so yes i believe it was justified for what i wanted to do.

With 700rpm less at 100km/h i expect longer engine life as the majority of time is spent coasting in top gear, temps were better and fuel economy improved........so eventually it will earn it's keep........but at the same time the enjoyment and performance of the close first four gears is priceless. Win win situation

Yeah i hear what you are $aying and pondered on that question with several mates........but now it's done, I do mark it as the single best modification i have done hands down.

matberry Moderator Go hard or go home

8,114 posts · joined Mar 2006 ·

#761136
Daimo's 5 speed surely is NICE to drive 😍😍😍.

One day he might get a real engine too.😂
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE

66brm Seriously Crusin Dubber

140 posts · joined Nov 2009 ·

#761139
Ok so say I do go down the Berg5 path, what ratios should I be looking at and who will build a beast like that, plus supply a RHD berg5 shifter?, total cost of the conversion in the $5-6000 ballpark?

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 ·

#761181
after having a ride in daimos bug i gotta say a 5 speed box is on my wish list too

i did the nutbag low 4th once too.
0.89 4th in a freeway flier....ooops was that a mistake
think normal 5 speed car going from 3rd straight to 5th 😂

66brm Seriously Crusin Dubber

140 posts · joined Nov 2009 ·

#761195
Hellbugged, can I ask who built your 5 speed? And if possible what ratio's you have?

colonel mustard Son of Jim - Creator of Good

2,829 posts · joined Feb 2009 ·

#761197
word on the street is that rod penrose picked up some Berg 5 speed stuff when he was in the states. give him a call 🙂 02 4272 9920

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 ·

#761284
According to the "internet" a 195 65 15 tyre is 24.98 inches tall,
so at 100km/h, (62mph),
just for reference,
1500 beetle box would be: approx 3050rpm

40hp box would be: approx 3230rpm

L-bug box would be: approx 3000rpm

A good option would be to use 1500 beetle third and fourth ratios,
and a custom ordered Albins first and second set that are taller,
and thus close up the gaps.
Your larger torque should make the taller 1st and 2nd gears quite nice to drive.

EG, 3.444 first gear, and 2.00 or 1.93 second, all using the most common 4.125 ratio diff.
westi wrote:That's mad Alan.

66brm Seriously Crusin Dubber

140 posts · joined Nov 2009 ·

#761951
DB did you recieve my PM?

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 ·

#761968
Nothing my end....it was full the other day, but there is some room now.
westi wrote:That's mad Alan.