Gearbox advice sought

[Tony C]

I'm about to swap my 1.8 K-Series (150 bhp) engine for a 230 bhp 2.0L Duratec.

 

People seem to specify a 5 speed box with a Duratec.

 

I have a 6 speed box which is now sitting on the garage floor ready to re-instal. The box has done 43,000 miles since May 2003, mostly on the road. There are no apparent problems with it - the change is nice and there are no strange noises. (Aren't earplugs worderful?) Mind you, a couple of curly pieces of steel swarf came out with the oil

 

Even though the 6 speed box is not necessary with a Duratec, I don't really want to spend money on a 5 speed unecesarily - I don't mind changing gear and I could always miss a gear or two.

 

Current thought process:

 

1. Clean-up the 6 speed and reinstal it.

2. Send it off for a check and refurbish (BGH or Road & Race - phone on Tuesday for advice & cost).

3. Part exchange it for a 5 speed (Looks like close to a grand).

 

Any thoughts or previous experience?

 

BRG Brooklands SV 😬 It seems that perfection is achieved not when there is nothing more to add, but when there is nothing more to take away. (Antoine de Saint-Exupery)

[F355GTS]

Tony

 

I think the issue is more the gearing in top, at 1 to 1 in 6th the 6 speed is considered too manic for more powerful engines, having said that I'm using one to good effect with a 3.62 diff in my car but then I only use it on track. If you are interested in a 5 speed we may be able to do a deal, I have a Quaife 5 speed semi helicoil box sitting a Road & Race not doing anything

 

Mark

 

Edited by - F355GTS on 30 Dec 2006 20:00:14

[Tony C]

Thanks Mark.

 

As the 6 speed is now out of the car this is the time to make the decision. I'd hate to put it all back together and THEN wish I'd gone for a 5 speed.

 

I have a 3.62 diff - I think!

 

I've noticed that the BGH 5 speeds have an overdrive 5th. Apart from that, comparing the ratios in the 6 speed, there's not that much difference.

 

I don't want to spend £1000-ish for a 5 speed for nothing, particularly as I think for my use the 6 speed will be OK.

 

If you don't mind, could you drop me an e-mail concerning the Quaife 5 speed; and what is a semi helical box?

 

BRG Brooklands SV 😬 It seems that perfection is achieved not when there is nothing more to add, but when there is nothing more to take away. (Antoine de Saint-Exupery)

[Jason Plato]

I'm also doing a 230bhp 2L nail and using my 6 speeder with a 3.62 diff.

 

If you do some research on a gear calculator ( the one on Arnie Webs site is good) then you will see that we will be doing about 4500 rpm @ 80 mph on the motorway with R888 tyres on. I think thats fine, and also it will achieve 138 mph at 7500 rpm, that should also be fine for all UK circuits.

 

I had my 6 speeder overhauled by R&Rt 2 weeks ago and it had a lot of wear, mainly from sprinting with cold oil and quick gearchanges. But it should be ok to handle the revs and 175lb torque from the nail . i look at it that with a 6 speeder you will have the better choice of ratios for every corner vs 5 speeder . But the motorway revs will be a little higher . I found the 6 speeder to work well with my previous 247bhp / 178lb K and I expect it to work well with the nail

 

I get the impression that most of the people who say the 5 speeder is "better" mostly cruise on the road and are a bit lazy in gear changing

 

here is C7 TOP

Taffia Area Rep

[John Howe]

For my two penneth... stay with the sex speed and use a 3.62 dif.

 

DJ comments are right on the button and the six speed gives you well spaced ratios, which to me is what the car is about, rather than an overdrive high 5th

 

JH

Deliveries by Saffron, the yellow 230bhp Sausage delivery machine

[Tony C]

Thanks Dave and John.

 

I'd pretty much decided to stay with the six, though I think a service might be adviseable. I'll give R&R a call on Tuesday and maybe they can fit a short shaft too

 

BRG Brooklands SV 😬 It seems that perfection is achieved not when there is nothing more to add, but when there is nothing more to take away. (Antoine de Saint-Exupery)

[Tre Zarcoff]

I hear that six speed box servicing can be expensive after it has been subjected to sprinting etc. 😳

 

I like cream...

[Tony C]

You again

 

BRG Brooklands SV 😬 It seems that perfection is achieved not when there is nothing more to add, but when there is nothing more to take away. (Antoine de Saint-Exupery)

[Jason Plato]

yeah - pain the ass isnt she 😬

 

yep big bills on my box Emma ..... power, revs, cold oil, thrashed = ££

 

all Ok now tho

 

here is C7 TOP

Taffia Area Rep

[Dobuy]

Keep the 6th speed, if you have one, why change. One thing I noticed on my car is what a big difference tyre size makes, even on the same rim size. I changed from 13" Hoosiers to Avon slicks and was finally able to use 5th convincingly on the Dubai Autodrome. And that was just a change in profile.

 

Duratec SV, built in Dubai