Been having a think RE cams and ratios..

[mardon]

Hopefully gonna be fitting a few mods over the next year or so. Cams and Diff.

Was thinking when Chip Wizards map the ECU to the new cams the rev limiter is set higher to make us of the higher peak power. If I fit the 1.4 XSi final drive to my gearbox when its getting refurbishing will the new limiter allow me to his 60-62 in 2nd gear?

Ratios on standard limiter: -

1.4xsi box
1st to 2nd 32
2nd to 3rd 57

Cheers all

[mardon]

Oh and my reason for asking.. rapid 0-60 times when the car is stripped followed by a good 1/4 time.

[Joesnow]

VTS/GTI @ 7250rpm

1st 34.8mph
2nd 61.9mph
3rd 88.8mph
4th 115.0mph
5th 142.1mph

VTS/GTI with 1.4xsi final drive @7250rpm

1st 31.9mph
2nd 56.8mph
3rd 81.5mph
4th 105.6mph
5th 130.4mph

VTS/GTI with 1.4xsi final drive@ 7800rpm

1st 34.4mph
2nd 61.2mph
3rd 87.7mph
4th 113.6mph
5th 140.3mph

Looks like quite a good combination… what you raising the limiter to? I just guessed 7800 as its quite common. It also depends on what diameter your tyres are these figures are based on the diameter being 56cm? – just guessed that too

[BENSAX3]

surly you should get more power raising the limiter on a standard box as it is faster then the xsi one with it raised aswell

[Ryan]

surly you should get more power raising the limiter on a standard box as it is faster then the xsi one with it raised aswell

changing the box doesnt give you more power ;)

and having a bigger top end in each gear doesnt make it faster! it means the gear is effectively taller.

thus slowing acceleration

[Toad]

VTS/GTI @ 7250rpm

1st 34.8mph
2nd 69.9mph
3rd 88.8mph
4th 115.0mph
5th 142.1mph

VTS/GTI with 1.4xsi final drive @7250rpm

1st 31.9mph
2nd 56.8mph
3rd 81.5mph
4th 105.6mph
5th 130.4mph

VTS/GTI with 1.4xsi final drive@ 7800rpm

1st 34.4mph
2nd 61.2mph
3rd 87.7mph
4th 113.6mph
5th 140.3mph

Looks like quite a good combination… what you raising the limiter to? I just guessed 7800 as its quite common. It also depends on what diameter your tyres are these figures are based on the diameter being 56cm? – just guessed that too


I think these figures are off a tad...

Standard GTI/VTS box does not hit 69.9 mph at 7250 rpm!!! I think I could hit somewhere around 66 at 7800 with my standard GTI box.

Anyway, why are you interested in 0 - 60? It's pontless. It's a bit like peak BHP figures... How many times in a race are you going to be going from 0 mph? Hopefully if you don't crash, just the once. ;)

Also, how many times are you going to be going over 120 mph? Not often... So if you can exchange that pointless topend for some better accelleration low down, you're on to a winner for sure.

Finally, the 1/4 mile. With the standard GTI/VTS gearbox, you will reach about 95 mph in 3rd gear with a limit of 7800. So if your car is fairly quick, you might find that you need to change up to 4th gear before crossing the line. If you have a S1 Rallye box, you will have to go into 4th anyway. So you've actually got the same gear changes to make in a 1/4 mile race.

Hope this helps chap.

[Joesnow]

I think these figures are off a tad...
Standard GTI/VTS box does not hit 69.9 mph at 7250 rpm!!! I think I could hit somewhere around 66 at 7800 with my standard GTI box.
.

now edited - typing error... that was meant to be 61.9mph

[Toad]

now edited - typing error... that was meant to be 61.9mph

:oops: Sorry mate!

[Ryan]

all the information is on ssc..

you dont need to re do it.

its all been done

[mardon]

Not sure what the limmiter would be raised to. But I guess it'd be to suit the new cam profile and its power curve. I was looking into the 1.4xsi box because you'd get good power gains but arround the same top speed per gear as if the car had standard box and limiter (does that make sense LOL). Top end is of no interest to me. Which tracks can you even hit top speed in the UK.

I hadn't thought about the change to 4th on the 1/4 though good point.

[mardon]

On a side note..

When your shifting the power up the rev range and the limiter is adjusted accordingly I take it its still bad to be reving that high even though the engine is still pulling at that point. Should you really be up rating internal parts too?

[Toad]

Mardon, the limiter doesn't even need raising IMO. Obviously depending on what cams you get of course. I'm using 708s, they are similar to the likes of Piper 285 and Newman phase 3. My limiter is 7800, but you don't need to hit it. It can come in handy, for example, if you have both hands on the wheel while cornering and you need to change, thus being able to keep it on full throttle for a little space of time.

If you are defo going for a track set up, get the S1 box, I have got in now and it's awesome! ;)

Don't worry about other internals if you are going with the cams i've listed above, you'll be fine.

[mardon]

So the power band isn't that much higher. I know since I did the mods on mine its not ran out of steam in 1st and 2nd coming upto the limmiter. Not done it in 3rd though.

Problem with the 1.3 box is I use the car everyday on the motorway and the revs'd be to high and the petrol would take a beating.

[Toad]

Track or road car, there's no in between when you start to take your car into the realms of racing. You need to make a decision and stick to it!

No mate, those cams won't change the power band by much. The 106 / Saxo has fairly high lift cams in as standard. It's 120 bhp 1600 cc remember! Hehe. You'll lose a tad at the lower revs, and with a good map, you'll see some nice gains in the midrange and a little at the top.

[mardon]

I'll have to stick to fast road car with a good chassis then :)

Think I may go for the PT-51's with the 1.4xsi box. Thats next year. As well as a quaife diff. This cars a money pit LOL. Thank god for Octobers pay rise!