View Full Version : Another Gearbox Thread
krobinson
06-06-05, 09:34 PM
Now that my engines away getting sorted. I'm undecided as to which gearbox i should source/run.
I have a WR F10 with a 4.18FD, and a WR F13 with a 4.18FD in the garage.
But i always felt that the F10 made the car too overgeared, especially with running the 16's.
Any suggestions for the best possible box from the vaux range i can run? And what car's i can source them from?
Keith
Surely an F13 CR box with a 4.18FD would be beautiful? Thats definately what i'd go for..............
Snowface
06-06-05, 10:32 PM
shouldn't be any difference between the two gearing wise.
I'd like to use an F13 CR 3.74 instead of the F13 WR 3.74 i have. It would be a good middle ground where i get the close ratio gearing but also get a fairly low revving engine at crusing speed.
I hardly ever get into 5th gear on the current box.
The F13 WR with 4.18 is also a good choice i suppose with similar attributes to the above mentioned.
I'd use the F13 meerly cause its stronger and you have it there incase you want to stick a larger small blcok engine in (16v) in future.
the F10 and F13 clusters are identicle (bar ratio changes) so how is the F13 stronger than an F10? hmmmm ;) ok
get an F13CR with a 3.94/4.18/4.29 FD and it will be fine.
if you really want to find out the speeds etc, measure from the centre of the hub to the floor of one of yer fornt wheels (obv level ground helps) and post it here (in mm) and i shall post some numbers when im at work tomorrow.
krobinson
06-06-05, 10:51 PM
F13 CR found in a GTE? If so, what FD does it come with?
If i can find one, and fit my 4.18FD, i recon i'd be onto a winner!
Keith
Aragorn
06-06-05, 10:56 PM
im gonna be fitting a WR4.18 to my 16v soon
it has slightly closer 1st-3rd than the CR3.74 but 4th and 5th are a little bit longer to help with crusing
http://kevingalloway.myby.co.uk/gearbox%20graph.xls
if u open that in excel u can plan with the ratios and final drives (theres a selection for WR and CR boxes at the bottom and u can key in the final drives and produce a graph
F13 CR found in a GTE? If so, what FD does it come with?
If i can find one, and fit my 4.18FD, i recon i'd be onto a winner!
Keith
Yep as found in most gte's and gsi's (i think some gte's came with a F13 WR box). They have a 3.74FD as standard.
Snowface
07-06-05, 06:57 PM
when i say stronger i don't mean physical strength, more of a metaphor.
i.e. Micheal Jacksons prosecution has a 'Strong' case.
:roll: :roll:
nathan.
07-06-05, 09:55 PM
Ive just changed my gears and final drive. Was WR, 3.74. Now its CR, 4.18.
Unbelievable difference. 5000rpm @ 90mph in 5th.
Really depends on what you want to use the car for? 1/4 mile? trackday's? just cruising?
I used the f10 cr gearset and a 4.18 found from a mk3 astra
Snowface
10-06-05, 08:25 PM
i bet their is a big difference, my WR 3.74 pulls past 100mph in 5th Gear at only 4000rpm.
nathan.
11-06-05, 09:59 AM
the revs hardly drop when changing from 3rd, 4th and 5th (about 500rpm)
so you are always within the 'powerband'. so it pulls very well through all the gears.
It does about 115mph red line in 5th
If i can find one, and fit my 4.18FD, i recon i'd be onto a winner!
Keith
Dan and I* have this set up to Keith, definatley the one to go for. If you want a higer top end speed you could always change the 5th gear to one from a WR cluster, however you will still be capable of around 120mph with the 16" wheels, not that you ever need to go above 70 of course.
Like Nathan said, you are constantly in the power band.
Jim
* I'm changing to a newer F13CR cluster which has a slightly longer first gear and sticking a 4.53FD in the gearbox. It'll be interesting to say the least, lol.
mikey14sr
11-06-05, 02:19 PM
I cant even remember how or where to find the gearbox code or how to decipher them, can anyone help?
keith, will a low geared box be a good idea with regular trips to the ring in the pipeline?
Aragorn
11-06-05, 05:36 PM
any car thats driven on public roads would be a total pig to drive with a CR 418 imo
if u take your existing WR418 box and drive around using 4th as the highest gear then that will give u an idea of 5th on a CR418 (they are the same ratios)
4th on my current box is too short for me and thats the same as 5th on a F20, get on a motorway and its screaming along at amillion rpm
iirc a cr418 at 70mph is at around 4000rpm which is just useless for any kinda long distance driving (90 will be nearing 5k)
the thing someone mentioned about fitting 5th from a WR box could be interesting tho. i thaught u couldnt change the gears themselves within clusters, only the final drives?
/me goes off to look into CR cluster and WR 5th gear
nathan.
11-06-05, 05:45 PM
I drive mine everyday to work. although I don't go down motorways, bypass's etc.
If you do alot of motorway driving, don't go for the cr 4.18.
I was deaf when i got to PVS after travelling down M1 for an hour at 5000rpm. :lol:
Aragorn
11-06-05, 05:49 PM
yep thats why i decided i wanted the WR418 however looking at things if i can fit a 5th ratio from a WR box and use the CR cluster that might give me excellent accelleration and a lovely 5th to drop it into on the motorway
mikey14sr
11-06-05, 06:35 PM
that realy would be the best compromise for people who only realy need fith for long journeys, if most of your driving is in-town, under 50mph you'll only need four shortish gears most of the time, and on the occasional long run to the shows and stuff a nice, low-revving and more petrol friendly fifth.
Aragorn, it was me that mentioned fitting a WR 5th gear. This was actually stus idea, and he has pretty good knowledge on gear boxes, so i assume it can be done. You may want to speak to him about it in more detail.
As for how the car drives, I've gotten use to it now. I'm never going to want to drive around 100+ mph all the time, so cruising at 70mph at 4000rpm isn't too bad, I think it may be slightly higher than that actually, lol.
However, the long journeys that I've made in it are not the greatest, lol. My ears were ringing when I got out of the car. Earplugs ar a must! Saying that, the car is striped out with no sound deadening at all.
Jim
Snowface
12-06-05, 11:17 AM
Yeah, 5th gear is seperate, so with a WR 5th gear in a CR 4.18 you would be going from 4000rpm in 4th to about 2650rpm in 5th if you change gear at 60mph.
Which isn't bad really.
Think i'm just going to find a CR with 3.74 as i'm going to be using it 99% on the Public road where i don't need the little bit xtra a 4.18 gives.
Aragorn
12-06-05, 11:33 AM
some graphs for comparison:
(all assuming 195/45r15 tyres and 6800rpm rev limit)
http://kevingalloway.myby.co.uk/graphs/cr374.jpg
http://kevingalloway.myby.co.uk/graphs/cr418.jpg
http://kevingalloway.myby.co.uk/graphs/wr418.jpg
http://kevingalloway.myby.co.uk/graphs/cr418wr5.jpg
krobinson
13-06-05, 06:07 PM
Aragorn, it was me that mentioned fitting a WR 5th gear. This was actually stus idea, and he has pretty good knowledge on gear boxes, so i assume it can be done. You may want to speak to him about it in more detail.
As for how the car drives, I've gotten use to it now. I'm never going to want to drive around 100+ mph all the time, so cruising at 70mph at 4000rpm isn't too bad, I think it may be slightly higher than that actually, lol.
However, the long journeys that I've made in it are not the greatest, lol. My ears were ringing when I got out of the car. Earplugs ar a must! Saying that, the car is striped out with no sound deadening at all.
Jim
Thats some good advise, thanks!
With regular trips to the ring, i still think the CR4.18 is the best option, as when i get there, the car will be so much more usable on the track. Expecially with its new spec, which will allow it to rev past 8k safely. We drove alot of the way last year at 65/70mph, so i cant see a problem sitting at 4-5k in 5th.
The pro's outweigh the con's really.
Keith
its just noisy lol, get ear plugs ;)
I run a F15cr ona 4.18 and for motorway cruising it's not the best, I can boot it in 5th at 70 and if she goes, but I'm already at 4k so engine wear is not too ncie prolonged over 5k
the best option imo is to have a F10WR cluster, and mod the chassi leg to be able to swap clusters without touchign the engine mounts. jack up car, remove pass wheel take of turret, slide out cluster swap over pinion, and slide in other. 20mins tops, so when you knwo you'll go on a long trip, ring etc. bang in the F10 and put the 13/15/17 cluster in a bag with you and swap it the evening/morngin before hitting the ring.
that way you get good cruise economy and a better gearset for the track not a halfway house.
i see a lot of grasstrackers etc do that dependning on the length of the straights etc.
even dropping the engine down it only takes an hour TOPS, which isnt too bad in all fairness.
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