Longer 5th gear for 172 box??

[sammyhale22]

Has anyone built a longer 5th for the 172/172 cup Gearboxes??? In my opinion the top speed is the only thing that lets the 172 and cup models down! I`ve had mine screaming in 5th gear at 140mph, surely there is room for a longer 5th gear? 160mph top speed would be nice so that we can beat the civic type r on the motorway!

Samuel

 

[Goodj]

Damn you're hero.

Anyway, I've been told no to a longer 5th gear before (looking for MPG's over MPH though!)

A longer final drive would work much the same, but could you live with your 0-60 being possibly as much as a tenth longer?

 

[Russ_16v]

Are you kidding? You would need a lot more power to get more top speed, it's not just about the gearing, stick another box in, buying the box, fitting costs + a new clutch = probably £800 gone, for what, maybe 2-3 mph to keep with with a Civic? tyo get any more you need more power. Out of interest what revs are you pulling at that speed?

 

[Russ_16v]

That was a very rushed reply and not very well explained by me lol

 

[Dan]

i dont think you would have enough power just to add a longer gear :S im sure theres a site on the web that does a formula to work out whats needed to increase top speed when drag and all that stuff are brought into it????

 

[Sam@NP]

You will need a lot more power to reach 160mph. The relationship between speed and drag is not a linear one.

 

[Russ_16v]

What i meant to say is with power, gearing and aerodynamics, you need to take in all 3 when wanting more speed (im talking high speed) if you were to find a gearbox that was 'longer' then you would most likely end up at the same speed (maybe a few mph more at very best, maybe a few mph less) as the engine now has to work harder to get you to the same speed due to the longer gearing. So if you had more power combined with that box you could get a bit more out of it, but the cost would be rediculous. You can get the same effect by sticking a silly big set of wheels on which will increase rolling radius and 'lengthen' gearing. Though as said you will be lucky to gain any mph due to the car having to work harder to get there.

 

[Sam@NP]

iirc the gearbox in 1*2s has top speed of around 150mph.

 

[Russ_16v]

Ph1 box is a bit longer than the ph2, but ph1 is speedo drive and ph2 speedo is off ABS sensor so as far as i know you couldn't use a ph1 box

 

[Russ_16v]

Edit, didnt see you had a cup, in that case you 'could' fit a ph1 box, but id be very suprised if you got it any faster - id be swapping my ph1 box for a cup box if i was keeping it, so it had 'slightly' better accelleration, and the extra revs im loosing at top is doesnt matter as you need a load of powe to use them anyway, so top speed will work out about the same

 

[sammyhale22]

I doubt the 172 cup would go anywhere near 150mph, mine is screaming at 140. If i`m not mistaken the ph2/cup had shorter 1st and 2nd gears to improve acceleration? At 140mph I`m around 7000rpm and it seems to hit a point where it will not push any further. I think the limiter is 7200rpm in 5th or something like that??

 

[Dan]

im thinking you will need atleast 250+hp to get anywhere near 160mph :S

 

[Dan]

I doubt the 172 cup would go anywhere near 150mph, mine is screaming at 140. If i`m not mistaken the ph2/cup had shorter 1st and 2nd gears to improve acceleration? At 140mph I`m around 7000rpm and it seems to hit a point where it will not push any further. I think the limiter is 7200rpm in 5th or something like that??

PH2 172/182 has a limit of 7K in 4th and 5th gear from factory

 

[Dan@SJM]

I had my old one pinging off the the limiter @160 indicated. That was ITB'd though.

 

[Russ_16v]

7000 rpm in 5th it should be. If you want to go faster then you need to spend big money mate. The ph2 box is different all through each gear, to give you an idea my old ph1 did 122mph in 4th at 7000 rpm, 142mph in 5th was around 6500 frm memory.

 

[Sam@NP]

A cup wont reach 150 mph unless you throw it off a cliff. You wont reach 160mph in your clio without big power and different gear ratios. Buy another car.

 

[Dan]

PH1 boxes are quite a bit longer then

about 110-115 in 4th from a phase 2 IIRC :S

 

[Dan]

I had my old one pinging off the the limiter @160 indicated. That was ITB'd though.

about 152-155 then when you count in the speedo is a little out

 

[Goodj]

ph.1 boxes were longer because they had less lard to haul over ph.2
Cup ph.2's obviously offset this slightly.

Would weight loss of a Cup help grab a couple of HP, or is that just to improve acceleration not V-Max?

 

[Russ_16v]

Sam's got it right with post 16 lol

 

[Sir_Dave]

Sam's got it right with post 16 lol

Most definately, my cup managed to get to 143 on the GPS, but it was in Germany, down a ruddy great big hill, slip streaming my mates LCR. It also took about 3 hours to get there iirc.

At that speed, it did not feel safe

 

[aucky]

im thinking you will need atleast 250+hp to get anywhere near 160mph :S

And a different car!
Dragging a bubble shaped car past 140mph is pretty counterproductive.

If he wants a better way to lose his licence in a Clio, he should buy a V6

 

[Goodj]

At that speed, it did not feel safe

at 80mph safety swiftly declines

 

[Yellow Dave]

so back to the longer 5th gear question, is one available? I can't remember the last time I went over 100 magic buttons so would be nice to have a longer 5th for motorway mpg

 

[Goodj]

so back to the longer 5th gear question, is one available? I can't remember the last time I went over 100 magic buttons so would be nice to have a longer 5th for motorway mpg

No, but you can chuck a longer final drive.

More MPG's
Less acceleration.

 

[Yellow Dave]

how much and where from? I can't imagine most noticing the drop in acceleration in real world conditions?

 

[shiftspark]

so back to the longer 5th gear question, is one available? I can't remember the last time I went over 100 magic buttons so would be nice to have a longer 5th for motorway mpg

Yes a laguna 5th gear fits, if your serious talk to Mark Fish or Agency Transmission

 

[Ex-User (19928)]

No, but you can chuck a longer final drive.

More MPG's
Less acceleration.

Whilst it's technically possible (and a lot easier than getting a longer 5th) I don't think anyone sells diffs for Clios with longer final drives... Could fit the dci box and then enjoy a ~190mph VMAX. You would not enjoy the drivability though.

 

[tom172cup]

Whilst it's technically possible (and a lot easier than getting a longer 5th) I don't think anyone sells diffs for Clios with longer final drives... Could fit the dci box and then enjoy a ~190mph VMAX. You would not enjoy the drivability though.

Why would it not be very nice to drive then

 

[Chris205]

I did once see 152 in my ph1 172 going down a decent hill but didnt take too long to get there.

MPG is better with the ph1 box but the rpm change between 4th and 5th when flat out takes you nearly out of the power band

 

[mitch1503]

All I know is iv hit the limiter in 5th and as chris said didn't take 2 long to get there.. J

 

[Wick]

I'm sorry, if you purchased a car to chase type R's in 5th then you have the wrong car... A good few hundred quid for an extra few mph top end, no thanks, can think of much better ways to spend it!

The only reason I can physically see feasible to change it would be MPG, but you'd have to be doing 40K miles a year in it to get your money back.

 

[Gildstar]

Maybe a 6th gear ? A friend of mine did the same with his evo 8 because he wanted to try and hit 200mph.

 

[not normal dan]

in my opinion theses cars arn't built for that, there more suited to buzzing down country lanes with there point an shoot abilties. Theres no skill in pulling 160mph down a motorway, tbh its just abit mindless

 

[Goodj]

Whilst it's technically possible (and a lot easier than getting a longer 5th) I don't think anyone sells diffs for Clios with longer final drives... Could fit the dci box and then enjoy a ~190mph VMAX. You would not enjoy the drivability though.

But you could get an existing box rebuilt with a longer final drive maybe?
OP shold speak to Agency and see what they say.

 

[mitch1503]

I'm sorry, if you purchased a car to chase type R's in 5th then you have the wrong car... A good few hundred quid for an extra few mph top end, no thanks, can think of much better ways to spend it!

The only reason I can physically see feasible to change it would be MPG, but you'd have to be doing 40K miles a year in it to get your money back.

Well I'm only 13k short of doing that but sod it if I wanted better mpg I'd buy a diesel

 

[Ex-User (19928)]

But you could get an existing box rebuilt with a longer final drive maybe?
OP shold speak to Agency and see what they say.

Anything's possible... But how much do you really want to spend on something that trivial.. I mean how many times does one wish to go over 140mph?

Might aswell sell the 172 and buy a V6 that can already do 160.

 

[ali_warriner]

OP if you want to 'beat' Type R's go and do some 1/4 mile drag racing.

Very easy with a stripped cup.

 

[Wick]

Well I'm only 13k short of doing that but sod it if I wanted better mpg I'd buy a diesel

Exactly my point.... There is no point lol!

 

[172Ben]

type r top speed is about 146mph anyway, not going off the clocks.

Even supercharged ones only get to around 158mph