206 GTI 180 gearbox

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David Floyd

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Tadpole
Tadpole
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Hi there folks, this is my first post to the forum, from a quick look it has lots of good information thanks.

I have three Pugs including a 206GTI180, a great little car. But it needs 6 gears- not possible so has anyone fitted a taller 5th gear or is it possible to get one made?

[I also have 306 xsi and about 20 years ago had a taller 5th from a 405 fitted to that and it was a significant improvement.] Any feedback much appreciated! Thanks
 
I haven't heard of a 6 speed BE.

The EP6 engines can use the BE 5 speed box in naturally aspirated models and the MCM 6 speed box in the more powerful EP6DT turbos. The 6 speed was made to handle the increased torque. The clutches differ and you might need to sort out the final drive. I don't know if your existing flywheel suits.

I don't know if the fixing holes match but you can compare with this pic:


mcm-2.jpg
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The construction of the boxes
 

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The simplest way to increase the gearing will be larger rims/tyres. There may be provision in the BSI to specify the size so the speedo reads correctly. Nexst is to find the same gearbox from another model, but with a taller final drive ratio. You'd need to go digging around the parts listings. These two changes would be easier than finding a 6 speed that can be retrofitted.
 
seasink said:
The EP6 engines can use the BE 5 speed box in naturally aspirated models and the MCM 6 speed box in the more powerful EP6DT turbos. The 6 speed was made to handle the increased torque. The clutches differ and you might need to sort out the final drive. I don't know if your existing flywheel suits.
Click to expand...
The 207 GTi has a 5sp BE gearbox.

There is even an eTuners page on a longer 5th gear mod for the 207, but I'm not sure if it would be appropriate for a GTi180.

eTuners link
 
I was referring to cars like the Citroen C4 B7 where the EP6 engine can have a BE 5 sp fitted, and the DS3 turbo EP6DT with the same block which always has an MCM 6 speed. C4s can also have the piloted version of the 6 speed, EGS.

I haven't compared, but perhaps the fixing hole pattern matches for both types, which would make a swap worth checking.

Does David Floyd want a longer top, or a spread of six ratios?
 
My 306 S16 has a modified BE3/5 gearbox. From memory, it's got the standard ratios for 1/2, lower ratio for 3/4, and standard ratio for 5th. I can't remember exactly what donors the pieces were assembled from; I bought the box complete.

What the gearbox ends up feeling like is the BE3/6 speed from the 306 GTi6, but without a 5th gear. Effectively like having 1, 2, 3, 4, 6. Great for city driving, and wherever there is a speed limit. I'd definitely feel that gap on a higher speed track, though.

Here is some information on the internet relevant to the older BE1 and BE3 gearboxes. Might give you an idea of some of the things that are possible, but there are some differences to the BE4/5 in the 206 GTi180.

As above, you're likely to have a much easier time with tyre sizing and final drive replacement.

What is the usage case? Reducing RPM at 110km/h? The engine is happy to sing all day at 3,000-4,000rpm. Some additional sound deadening may achieve the outcome, and additionally isolate some road noise.
 
Strange. If anything, I always thought 5th in a GTi180 was too long.
 
The gti 6 gearbox is a BE 6 speed….

Its not actually an extra gear but closer spacing in between gears.

You can fit a longer 5th gear in the be4r that you have.
 
David S said:
Next is to find the same gearbox from another model, but with a taller final drive ratio.
Click to expand...
Isn't a different FD the difference in the gearing between a GTI and a GTI180 (3.79 v 3.95)? I think all the 206s other than the 180, including the diesels, had a 3.79 FD.

Maybe you could put the gearbox (or the 5th - 0.68) from a diesel into it...
 
I am going to fit a diesel 5th gear to my Be3 to give it far longer legs, economy on open road. They are available on the net. It has been done before locally.
 
Why do you think the fuel economy will improve? The load on the engine won’t change. ie the road frictional losses + wind load + force due to gravity, remain the same, provided you’re still at peak efficiency. A perfect example of this is an Mi16, which runs at 31.4 km/h/1000RPM yet can easily manage 6.6 L/100km at 90 km/h.
 
I'm guessing that the 'provided you’re still at peak efficiency' qualifier is where the difference emerges. Friction; intake air throttling; maybe other things probably vary with RPM.

I guess first you work out how much power is required to keep your car running at the speed you want (say 100k/hr).

Say we're in a Mi16 at sea level.
c (drag) 0.34
Frontal area 2.4m^2

P = 0.5 * c * D * A * v^3
= 0.5 * 0.34 * 1.25 * 2.4 * 27.8^3
≈ 11 kW atw
≈ 13 kW at the crank (say)

Then work out what RPM for 100 kmh:
PeterT's Mi16, in 5th = 3184
Same car with a diesel (0.68) 5th = 2857

Then calculate torque (Nm) = 9.5488 x Power (kW) / Speed (RPM)
Stock Mi16 = 36 Nm
Diesel 5th Mi16 = 40 Nm

Then check the Brake Specific Fuel Consumption for the particular engine at those two points:
3184 RPM, 39Nm
2857 RPM, 43.5Nm

and then you'll have your g/kW hour. Times by 13 for g/100km, divide by 737.22 for l/100km.

I reckon the BSFC will be (slightly) less at the lower RPM/higher torque point.

Now, has anyone ever seen a BSFC plot for an XU10...?
 
That's my thinking, just got a new appreciation / love for mech eng!
 
Put more simply, Power (W) = Force (N) x velocity (m/s). If the forces and velocity don't change, then the power required doesn't change. I would expect frictional forces from transmission & tyres and wind forces, far exceed other changes in friction from a drop of a few hundred rpm.
 
And the motor can certainly take 3500-4000 at 120kph all day!

Its obviously a little louder…just turn the beats up!
 
PeterT said:
Put more simply, Power (W) = Force (N) x velocity (m/s). If the forces and velocity don't change, then the power required doesn't change. I would expect frictional forces from transmission & tyres and wind forces, far exceed other changes in friction from a drop of a few hundred rpm.
Click to expand...

Yeah, for sure. If the BSFC from a Saturn I4 1.9l DOHC is anything to go by (sorry - that's the best I could do with Google), it looks like a difference of <10% (<0.5 l/100km, or ~$1/100km in Melbourne atm).

BBWi6.png
 
My 16v 205 has diff 4.063 with 5th 0.757. & pulls like a bull. Fitted with 205x50x15s and weighs 1000kg

Mid October '22 I drove from Brisbane to Sydney down the coast road, if 5th was any shorter it would have completely driven me nuts.

In 2008 I drove it to Mt Gambier at around 90kph all the way. 47mpg. (sorry about the units)

I would not hesitate putting a diesel 5th (0.658) in my 205.
 
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