Westy, optimum power output ?

[AdamR]

Tried the 3.92 Sierra diff and MT box - on track it was just 3rd and 4th for me, the novice

 

Then tried a 3.62 diff ... so then it was 2nd 3rd and briefly 4th - must try harder! Did feel a little slower off the mark, or could have just been me convincing myself. Crused nicely at 70 though on the road!

 

 

Not just you... You effectively lost ~10% 'power' (torque at the rear wheels) with that diff swap.

[Kingster]

Mine's 185bhp, 173ftlb (with a nice wide spread from 3-5k rpm), 3.92 diff, 15" wheels and I'm pretty happy at that (you've been in it at Blyton Adam) - will be putting a BGH E6 in it as soon as I get the time and reckon that will make it a pretty nice combo

 

Not tried many other cars - or been up against that many, but never yet felt the urge for more power (well, not since fitting the current Blacktop anyway).

[Kingster]

Point to add here - following on from other thread discussing power and dynos at length - my 185 might not be the same as Adam's 185 as they were no doubt measured on different dynos etc.

 

But all I know is my car now drives and feels way better than it did with a 168bhp (allegedly) Silvertop. So regardless of headline figure, my "bum" dyno says it's more for sure! However, no idea if I'd like or need a further hike in power/torque - but we shall see

[Cleggy the Spyder Man]

all depends upon the how the car is setup, the ability of the driver and the tyre choice and conditions

 

just had mine in at MNS for cams and now makes 209bhp - car feels fantastic and does not struggle at all but it is very well setup (IMO) and always has good rubber on it - it's not over tyred as well

 

Is it more enjoyable to drive than when it was 180 bhp - no not really

[KugaWestie]

Mine is around 225bhp and 190 ft lbs at the fly (estimated of course)

 

Running a standard MX5 5 speed gearbox coupled to a 3.6 LSD

 

I found with the MX5 box using a 4.1 diff the gears were too short, having to change twice to get past 60mph.

 

Now I can get just past 60 in 2nd and top out at 90 in third and 120 in 4th

 

I definitely would not go back to the 4.1 diff, and dont think I would notice that much difference between the 3.6 and and the other option which is a 3.9

 

All on 195 x 50 x 15's

[Dommo]

Looking at data logs, I was a better driver at 165bhp than 260bhp, then again better at 260bhp than 335bhp. Car gets quicker, driver gets slower

[KugaWestie]

Looking at data logs, I was a better driver at 165bhp than 260bhp, then again better at 260bhp than 335bhp. Car gets quicker, driver gets slower

 

[AdamR]

Looking at data logs, I was a better driver at 165bhp than 260bhp, then again better at 260bhp than 335bhp. Car gets quicker, driver gets slower

That's a good point to raise... I always find the same.

[The Cheese]

Mine was dynod at Northampton motorsports and is 208bhp and 179 torque and I feel that's easy enough and after struggling to get the adrenaline going after coming from motorbikes , this now fills a void

Unless it's wet then I can't use it

[AdamR]

Unless it's wet then I can't use it

 

Why not? Should be loads of fun in the wet!

[The Cheese]

Why not? Should be loads of fun in the wet!

[The Cheese]

Guess I'm still a nunney in the wet I was same on the bike

[B.RAD]

Diff, gearbox, wheels/tyres aside, and assuming the car is set up properly, my response would go like this (based on experience of each type):

130bhp for a road only car. That way you use it all the time and it makes for the most rewarding on the road experience. Windscreen with wind deflectors, sunnies on, still the quickest car out there.

180bhp for road and track. Rewarding and reliable, much more on the road starts to become unusable.

220bhp+ for track only and competition. Then you're into how much you can use based on your talent and what tyres you choose to run.

[Yanto]

180bhp for road and track. Rewarding and reliable, much more on the road starts to become unusable.

 

Point of order, as I tell my Mrs the accelerator is not an on/off switch it can be moderated to any point in between (that is a lie - she is a very sedate driver),

 

My point is that; even for a numpty like me 180 plus is not unusable, in fact the more you have the more usable it becomes as overtaking becomes easier, but if a driver does find it unusable then it is the driver's fault, not the car's 

[B.RAD]

Point of order, you can't use all the power and all the revs beyond the likes of 180bhp unless you speed. Mine is 221bhp and while I love bumbling along at below 3000 rpm, enjoying the induction sound and farts from the exhaust, when I use the loud pedal even in fractional amounts, the closing speeds become dangerous. Mine is unusual as it'll do 50mph in first and over 90 in third. If you do use all the revs, and therefore all the power, it's for the briefest of moments up to 70mph. Unless you've got a v8 where your power peaks at 5000rpm of course.

But thanks for the driving lesson though.