Gearbox ratios and shorter 5th

[1985michael182]

Ok so after cadwell yesterday I found that I never needed 5th as when I changed up into it I wasn't pulling as well as 4th as I dropped off the power. What would be the fix? Shorter 5th gear set or leave the ratios and change the final drive to shorten all the gears ? Been talking to northloop and he will rebuild my 172 cup gear box with the bolted diff from the 182, but thinking whilst he's in there I need to change something. Would the m factory final drive kit from PMS fit the 182 diff or do I have to go with the m factory diff aswell?
Need some boffins to give me some info in lamens terms so I can make an informed decision.

 

[Aydon182]

Sequential box

 

[JamesBryan]

I'd leave final drive and do quaife diff and Megane 5th gear.

 

[1985michael182]

Can't stretch to quaife to be honest. Just want more usable power range

 

[1985michael182]

And no to sequential

 

[JamesBryan]

Can't stretch to quaife to be honest. Just want more usable power range

It's not that much more for the Quaife when you factor in the machine work and yoke retaining plate needed for the MFactory. I'm sure it's around £900 by the time it's done. Quaife is £1030 all in.

 

[1985michael182]

Ok so am I right in saying that the m factory final drive can only be used with their diff and no others? If I went quaife the ratios would still be the same but no machining is required to fit. So I would be no better off it here that pitting power to the wheel with most traction?

 

[1985michael182]

@NorthloopCup

 

[JamesBryan]

Not sure on the MFactory FD.

But the Quaife does need the crown wheel from the standard diff machining to fit the Quaife, which Quaife do for you. You'd then add the Megane 5th gear.

That's my suggestion.

 

[Aydon182]

Do you use the car competitively? Any modifications? I haven't often seen anyone overly concerned with the gear ratios that much, I just watched back a video from the 750mc and on the longest straight at cadwell the Clio was only just getting to the limiter in 4th, seems like you'd have your foot on wide open for a couple seconds max if you got the best possible entry to the straight

 

[NorthloopCup]

The last thing you want is a 5.25 ratio. 1st gear will be pointless, so all you would've done is successfully converted the 5spd box into a 4spd with crawler gear. Lol!!

Only option you'd have really is a gripper diff and one of their crownwheel and pinions. Easy way to spend £1500+ though.

My cup on grp n cam timing worked better than the standard setup as it allowed a greater power/torque spread. That's where I'd be looking personally - making the engine more useable.

 

[bashracing]

I did a lot of research on ratios for the hillclimber and what Mark says above is 100%
you can do it on the cheap with the shorter fifth gear set but ultimately the gripper final drive is the way to go for the required results,


''Give a man a fish and feed him for a day, Teach him how to fish and feed him for a lifetime''


--------------------------------

http://johnmaherracing.com/calculators/gear-ratio-calculator/


-----------------------------------

Clio 182
JC5- 130: 1st: 3.091 2nd: 1.864 3rd: 1.321 4th: 1.029 5th: 0.795
Final Drive: 4.067

Clio 172 phase 1
JC5-089: 1st: 3.091 2nd: 1.864 3rd: 1.321 4th: 1.029 5th: 0.795
Final Drive: 3.867

Clio 172 cup
JC5-129: 1st: 3.091 2nd: 1.864 3rd: 1.321 4th: 1.029 5th: 0.795
Final Drive: 4.067


------------------------------
Available gripper final drive Ratios

5.25
4.54
4.28
---------------------------------
All other JC5 ratios
JC5 Renault Gearbox Ratios / Relations
JC5-014: 1st: 3.091 2nd: 1.864 3rd: 1.321 4th: 1.029 5th: 0.794 Final Drive: 4.067
JC5-053: 1st: 3.363 2nd: 1.864 3rd: 1.321 4th: 1.029 5th: 0.821 Final Drive: 4.067
JC5-062: 1st: 3.364 2nd: 1.864 3rd: 1.321 4th: 1.029 5th: 0.795 Final Drive: 4.067
JC5-070: 1st: 3.727 2nd: 2.048 3rd: 1.321 4th: 0.971 5th: 0.795 Final Drive: 4.067
JC5-072: 1st: 3.727 2nd: 2.048 3rd: 1.321 4th: 0.971 5th: 0.738 Final Drive: 3.733 F9Q 736 Engine
JC5-089: 1st: 3.091 2nd: 1.864 3rd: 1.321 4th: 1.029 5th: 0.795 Final Drive: 3.867
JC5-090: 1st: 3.364 2nd: 1.864 3rd: 1.321 4th: 1.029 5th: 0.821 Final Drive: 3.867
JC5-100: 1st: 3.727 2nd: 2.048 3rd: 1.393 4th: 1.097 5th: 0.821 Final Drive: 3.867
JC5-103: 1st: 3.727 2nd: 2.048 3rd: 1.321 4th: 0.971 5th: 0.738 Final Drive: 3.733 F9Q 736 Engine
JC5-106: 1st: 3.727 2nd: 2.048 3rd: 1.393 4th: 1.097 5th: 0.892 Final Drive: 3.563
JC5-107: 1st: 3.727 2nd: 2.048 3rd: 1.321 4th: 0.971 5th: 0.738 Final Drive: 3.294 Megane 1.9dCi F9Q 105hp Gearbox
JC5-113: 1st: 3.727 2nd: 2.048 3rd: 1.321 4th: 0.971 5th: 0.756 Final Drive: 3.563 F9Q 732 Engine
JC5-108: 1st: 3.364 2nd: 1.864 3rd: 1.321 4th: 1.029 5th: 0.821 Final Drive: 4.067
JC5-109: 1st: 3.727 2nd: 2.048 3rd: 1.321 4th: 0.971 5th: 0.738 Final Drive: 3.733
JC5-119: 1st: 3.727 2nd: 2.048 3rd: 1.321 4th: 0.971 5th: 0.795 Final Drive: 4.067
JC5-120: 1st: 3.727 2nd: 2.048 3rd: 1.321 4th: 0.971 5th: 0.738 Final Drive: 3.867
JC5-125: 1st: 3.364 2nd: 1.864 3rd: 1.321 4th: 0.971 5th: 0.756 Final Drive: 3.867
JC5-126: 1st: 3.727 2nd: 2.048 3rd: 1.321 4th: 0.971 5th: 0.756 Final Drive: 3.563
JC5-128: 1st: 3.727 2nd: 2.048 3rd: 1.321 4th: 0.971 5th: 0.756 Final Drive: 3.294
JC5-129: 1st: 3.091 2nd: 1.864 3rd: 1.321 4th: 1.029 5th: 0.795 Final Drive: 4.067
JC5-130: 1st: 3.091 2nd: 1.864 3rd: 1.321 4th: 1.029 5th: 0.795 Final Drive: 4.067
JC5-131: 1st: 3.364 2nd: 1.864 3rd: 1.321 4th: 1.029 5th: 0.821 Final Drive: 3.867
JC5-132: 1st: 3.727 2nd: 2.048 3rd: 1.321 4th: 0.971 5th: 0.756 Final Drive: 3.563
JC5-137: 1st: 3.364 2nd: 1.864 3rd: 1.321 4th: 1.029 5th: 0.821 Final Drive: 4.067
JC5-138: 1st: 3.727 2nd: 2.048 3rd: 1.321 4th: 0.971 5th: 0.738 Final Drive: 3.294
JC5-140: 1st: 3.727 2nd: 2.048 3rd: 1.321 4th: 0.971 5th: 0.756 Final Drive: 3.294
JC5-144: 1st: 3.727 2nd: 2.048 3rd: 1.321 4th: 0.971 5th: 0.756 Final Drive: 3.294

 

[1985michael182]

Ok i understand. Yes was around 110mph before breaking point, going to fith 3/4's up the hill just slowed me down So stayed in 4th scream at me. So the gripper 4.28 would be a slightly better on ratios and not ruin 1st gear but means spending £1500 Just to get the desired effect.
Nothing competitive yet just learning the clio. Mods are stainless 421 manifold and straight through to back box. Ktec induction and remap so far with limiter slightly raised.
With the gripper don't you have to send it to get serviced aswell, where as the quaife can just be left alone?
I think for now the bolted diff will be ok and change the 5th gear for the shorter one then when things get more serious throw a propper diff at it.
With the group n timing is there any parts required or just tweaks to be made?

 

[1985michael182]

http://www.pure-motorsport.co.uk/cl...boxdrivetrain/jc5-higher-fifth-gear-pair.html

O.891 33/37 5th gear set £150
Will this be Ok?

 

[bashracing]

That's the megane 5th that Northloopcup uses,

 

[1985michael182]

Ok that's the plan then. Thanks everyone for your help. Appreciate it

 

[1985michael182]

Whose this guy because the car is rapid and very close ratios

 

[NorthloopCup]

@Russ Rallye

 

[Russ Rallye]

Yeah that's mine, gearbox wise it's got the shorter Megane 5th gear and gripper diff + their final drive. Like mark says the 5.25 final drive will be useless and I suspect is (pardon the pun) geared towards the rally boys probably.
Russ

 

[1985michael182]

Cars bloody quick. Is there anything in his class that's as quick it? Seems to be leaving everything for dead

 

[1985michael182]

Ah hello Russ. Very impressed with your Clio. Which final drive did you go for?

 

[1985michael182]

Where your going through the mountain in 3rd on cam im in second on cam. Tried 3rd just cam off the power. Also what's your entry speed into coppice in 5th? In 4th I was at 100ish depending on how well I came out of barn

 

[Russ Rallye]

Thanks @1985michael172 that was a couple of years ago so should be a bit quicker now or will be once it's back in one piece. Will have to check which Cw/p it is but it's either the 13/59 or 14/60 mate.
Russ

 

[Russ Rallye]

Where your going through the mountain in 3rd on cam im in second on cam. Tried 3rd just cam off the power. Also what's your entry speed into coppice in 5th? In 4th I was at 100ish depending on how well I came out of barn

Would have to have a look at my data from my dash to be honest, the fastest lap that weekend was a 1.42 something but it'll go a fair bit faster as that wasn't fully dry and on R888's.
Russ

 

[Goodj]

If you can get into 5th at Cadwell, you'll be clean out of gears 1/2 way down the Bentley straight, and have detonated your engine at the end of Hangar

 

[1985michael182]

I'm coming from an impreza to the Clio and I have to say having alot more fun! Just testing the water at the minute, but from research on here changing diffs and ratios are a massive improvement mod and pound for pound one of the most performance enhancing to keep on the power and pulling through the corners. With the gripper do you have to get it serviced every so many miles?

 

[Russ Rallye]

If you can get into 5th at Cadwell, you'll be clean out of gears 1/2 way down the Bentley straight, and have detonated your engine at the end of Hangar
:wink:

Changing 5th gear for a longer one is only a minor job that can be done in the car if need be. With this gearing the car will pull a genuine 133mph @7800rpm on 15's. There isn't that many places in the uk where we race that you'll need more than that in a Clio.
Russ

 

[Russ Rallye]

I'm coming from an impreza to the Clio and I have to say having alot more fun! Just testing the water at the minute, but from research on here changing diffs and ratios are a massive improvement mod and pound for pound one of the most performance enhancing to keep on the power and pulling through the corners. With the gripper do you have to get it serviced every so many miles?

I have my gripper serviced at the end of each season and it always needs new plates fitted, standard service is approx £120.
Russ

 

[1985michael182]

Do you still nacker synchros then like 3rd or second ?

 

[Russ Rallye]

Do you still nacker synchros then like 3rd or second ?

There's always a synchro or selector fork to change when the box is apart.
Russ

 

[NorthloopCup]

There's always a synchro or selector fork to change when the box is apart.
Russ

That's why I had the improved synchro rings sorted out for 3rd/4th gear.

 

[1985michael182]

I'm learning, this is good. What setup do you have engine wise Russ?

 

[Russ Rallye]

I'm learning, this is good. What setup do you have engine wise Russ?

That's a fairly standard engine in the video, 421 cams and jenvey throttle bodies. Circa 215bhp.
Russ

 

[1985michael182]

That's not fairly standard! Thats like £2500 of mods!
Fairly standard is an induction and manifold with a map at about 175/180.

 

[Russ Rallye]

Well you know what I mean, standard internally bar ARP con rod bolts and just the usual exhaust with cams and bodies. £2500 is small change compared to what its cost to build. Full thread is HERE if you want to have a look, some big updates coming shortly when it all goes back together.
Russ

 

[1985michael182]

So really in that video the gearbox changes made the car as quickness it was

 

[1985michael182]

Quick*

 

[Aydon182]

Quick*

it's 215 bhp itb'd , its going to climb rpm's much faster than std, in my turbo 1st gear is almost redundant

 

[JKING3008]

Bump on this thread.

My gearbox is getting pulled apart to replace the selector seal shortly, and I am also looking at the shorter 5th gear or gripper final drive (13/59 or 14/60).

What would would be the recommendation?