9 replies to this topic

[MinBinPat]

Decided that the Vauxhall C16se is the most practical way to go for me, with cheap engines available etc 100 bhp available and of course 5 speed box.However I cannot find much info here about which is the best box to use with 10" wheels. I understand it is a toss up between an Astra Diesel F13 w or an F15 from Corsa TDi. Has anyone in here used either of these boxes and got any feedback on how they run, things like revs in gears top speed acceleration etc?

Regards

[The Matt]

I've got an F15WR on mine, I'm running 165/70R10s.

I did an Excel spreadsheet for the F15WR (wide ratio from the astra TD) and the F15CR (from the Corsa petrols) and plotted the gear ratios and assumed both had a 3.55 FD ratio.

It's not 100% accurate, but it's pretty close from the info I had. If you want me to send the spreadsheet through, I can, but here's a screen grab that may help

Attached Files

•  f15WR vs F15CR.jpg   115.36K   47 downloads

[The Matt]

The other things to consider:

Get the earlier gearboxes and a flat flywheel, not a pot type flywheel. The earlier gearboxes make is SO easy to change the clutch in-situ.

There was an access plate underneath the bellhousing, four M6 bolts and that comes off, the new clutch kits came with a series of clips... you spin the flywheel round, get a mate to press the clutch pedal, put teh clip on the clutch plate nad pressure plate, spin the flywheel around get a mate to press the clutch....repeat until all four clips are on and the clutch and pressure plate are then held together in the disengaged position. Undo the 6 M6 clutch retaining bolts....

You then pop a cap off the end of the gearbox, pop a circlip off and withdraw the input shaft enough to be able to drop the clutch and pressure plate down through the access hole.

Then transfer the clips onto the new clutch plate and pressure plate, slide that back in, pop the shaft back in through the centre of the clutch plate, pop the circlip on the end of it, pop the cap back into the end of the gearbox casing.....

Tighten the 6 retaining bolts into the flywheel, release the clips, re-fit the access plate and it's all sorted. Literally takes half an hour to change the clutch then.

The other thing you'll want to do is NEVER try and get the cable type clutch working, hydraulic is so much better, so get a gearbox with the hydro slave.

[The Matt]

Like the attached piccy.

Now, the difficulty is finding a box with a hydraulic slave cylinder AND the aforementioned access plate... I don't think you will find one, so if you look at the picture I've attached, you can see that the hydro slave fits in place of the normal release bearing, you can even see the hole in the gearbox where the pipe passes through is the same hole as the normal mechanical clutch arm.

IMO, you want an F15WR with a longer diff ratio than the 3.55, but I don't know where you can get that, so it may be a case of finding the F15WR and 3.55:1 combo that I've got. Don't get me wrong, it's OK, but I'd like to be able to get to 30+ in first and 60+ in 2nd. I think something like a 3.3:1 would be OK for me really.

http://oege.ie.hva.n...ing Corsa B.jpg

There's a link to various Corsa B gear options, have a look there and find what's most suited to your needs/driving

Attached Files

•  slave.jpg   18.17K   9 downloads

[M J W J]

An F17 WR has the same first and last gear as the F15WR. There are also the new F17+WR V1 and F17+ER gearboxes that have really tall fifth gears. Doesn't fully cure the final drive problem but it will give you a higher top speed in theory just slower acceleration.

The casings are the same as well as the differential so you can swap the mechanical speedometer drive over if needed. Also F17 gearboxes usually now come with the hydraulic clutch release mechanism fitted. Don't press the oil seal out in them though. They are near impossible to get a replacement. They are a special seal that only Vauxhall seems to have but won't sell you separately.

Check out this link for the gear rations (apologies its all in German).

http://www.opel-info...triebe/f17.html

Also don't make the mistake I made. You can't fit an f16, f18, f20 or f28 to a small block engine without modification to the flywheel and clutch.

[kappa]

What about a f13c box, as this is one I bought to run in my mini which has already got a f13 box in there. Also is this box a close-ratio box, or does the code need to be f13cr?

Will the f13c box work well with my engine and I am running 6 x 10" rims with 165x70x10's on there.

Cheers

Bobby

[BenH]

Hi Matt or Mike could between the pair of you sort of compare the f13wr and f15wr, iv got the f13 wr in mine but if the f15 will fit the e16se im up for trying that, im struggling with top end speed, cant seem to get over 100mph, 4th sees me to 95mph 5th drops my revs but only gains me the other 5mph, been told im overfuelling so may be down to that but Matts figures seem quite impressive

[M J W J]

Ben you need a taller final drive. You will loose the acceleration (sub 600 kg mini with 120 bhp will still shift) but you will gain top end speed and should help with the wheel spin.

I posted up how to work out all the gear ratios on your build thread on 16v. I know its long winded but it is the way to find the absolute best gearbox. There is a link on that post with loads on info on vauxhall gearboxes.

You need to find out exactly what f13 wr gearbox you have as there are a number of different 5th gears. Some have the same as the F15 so if they have the same final drive then it will make no difference to your top speed.

As for first and second gear it depends again on what f13 wr gearbox you have. Some have the same 1st and 2nd as the f15 so you would have the same wheel spin problems with either.

I am guessing that you have a shorter final drive than Matt. Either a 3.94 or even 4.18 which would be terrible.

I've got a 3.74 final drive and internals from an F17 CR box somewhere if you want it. The cluster won't be great but the final drive may be better. Its a hassle but you could swap just the final drive of your F13 WR box. The joys of rebuilding vauxhall gearboxes . Make sure you have a good set of pullers to hand.

All the odd number gearboxes (and f10) are interchangeable and the casings are the same. My F17 is built from 3 others.

By the looks of it if I have problems with wheel spin I am best to put the 1st gear out of my f10 gearbox I have into the F17 I have built up. It all depends on whether it can take the torque from my engine. Long way to go though.

[MinBinPat]

Wow, guys this is getting as clear as mud by the minute. So there's really no definitive answer other than suck it and see. I have really been struggling to get hold of an old vauxhall round my way, Biggleswade Beds, but i did get a Honda B16a2 locally so I think this is the way to go. Unfortunately I only got the engine and I am now thinking I really need a complete car for all the silly little odds and sods. I'll think about it while I continue welding which is going on forever...but the end is coming closer.
Great forum.

Pat.

[M J W J]

MinBinPat

It really depends on what you want from your mini. No one can give you a clear answer as everybody has different driving styles. If you spend most of your time in town driving then a shorter ratio gearbox would be better. If you spend a lot of time on motorways and a roads then a longer ratio gearbox with taller final drive would be better. It also depends on what rpm you engine revs to and at what rpm maximum torque and maximum power is made at.

X series vauxhall engines such as the x16xe are easy enough to find. Look for mk 4 astras, corsa sri's etc. Z series engines are the same just with a different manifold and ecu set up. if you are going to throttle bodies and a megasquirt kit then it doesn't matter.

Getting a final drive gear ratio that works well for a honda engine is more difficult. With vauxhall engines you want a gearbox from a diesel. For honda engines you will need to most likely buy a custom final drive ratio.

The link below is to BenH's build diary. I explained on that how to work out the optimum gear ratio.

http://www.16vminicl...t=24993&page=21