200 gear in a 197?

[oferh]

I understand that Renault changed the gear ratios in the 200 and shortened 1st through 3rd. Is it possible/any good to change the gear ratios for a 197 to those of the 200?

 

[StevoR27]

Doubt it, the 200 has a new gearbox, remapped ecu (possibly a different ecu) and also a larger cylinder head...

 

[Foxspeed]

externally the 200 engine and gearbox is the same

changes are internally - ie different gears and changes to the cylinder head

the ecu is just mapped differently

so you can fit a 200 g/box to a 197 and fit a 200 head or engine to a 197

 

[StevoR27]

I think the question was is it feasible to carry this out, changing the engine or cylinder head and replacing the gearbox is probably gonna be a big task. Better to get either a later 197 or a 200 and swap the nose if you don't like it

 

[richandgem]

would be a lot of work for 3bhp, and isn't the 200 box just the revised 197 one?

 

[StevoR27]

Not sure....does the revised 197 one have shorter 1-3 gearing. The 200 gears definitely feel alot different around town.

 

[R32pete]

The 200 has different ratio's to the 197 hence contributing to the faster 0-60, If you could get hold of a gearbox froma 200 you could bolt it straight on, ecu and so on would be irrelevant, Not sure how the shift light would be effected though,

 

[StevoR27]

I think the ECU and mapping would be quite significant to the results of putting a 200 gearbox in a 197.

The 200 behaves quite differently to the 197, 20lb of extra torque is delivered smoother and lower down the rev range, taking advantage of the shorter ratios of gears 1-3. Peak torque is also lower than the 197 at around 4500rpm (the 200 gearbox is setup to take advantage of this).

Ultimately it's not going to be an easy job. New gearboxes aren't cheap, and getting the 197 engine running in exactly the same way as a 200 engine won't be possible without physical modifications.

 

[R32pete]

Surely the 197's lower torque low down will benifit more from the shorter ratios, that way when you shift in 1st 2nd and 3rd your back into the power band faster? this is why I never put longer ratios into my supercharged r32 because it ment on changing up I would come back in with less rom's and ultimately less boost that with tfe closer ratios,

I was always of the impression closer ratios suited lower power cars?

Pete

 

[StevoR27]

Shorter ratio do increase acceleration but you can't just throw a short ratio box in a car and expect it just give you better results. The torque and timing is different which is why the 200 has a different box.

The ratio's of the 200 box would cause a 197 to have more flat spots when exiting corners and changing up. The 197 is less responsive lower down and does not hit peak torque until above 5000rpm. The ratios in the 197 box are design to take advantage of this as you shift up the gears and drop into this range hitting peak torque through each gear.

The ratio's in the 200 are set to take advange of peak torque being lower than 5000rpm so the top two gears can be taller.

 

[R32pete]

Ahh that makes sense, so with the right mapping the 197 could still benefit from closer ratios though? I guess if Renault thoughttgey could make it faster ther would have originally,

Pete

 

[StevoR27]

Exactly mate, the 200 block is clearly capable of producing more power for less emissions.

The only way you can really push the power up on the 197 is by adjusting the injection timing, raising the rev limit and burning more fuel (and oil!)

Whether you could get this to work with the 200 box I don't know. You'd probably need a better ECU for a start