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Car tuned by Mike Moto-East, 160 kw atw around 265 NM.
Car drives very nicely indeed and I am happy with Mikes work.
However, I am seeking quicker acceleration without going build engine internals.
Thinking
1) lightened flywheel
2) cams
3) further tuning
Emphasis is on acceleration not power figures.
Any ideas welcomed.
Novice1 aka Ron

Power= acceleration.

You're going to want compression, cams, gears, porting or a bigger pulley.

I'd want it to breathe at the top if I was worried about breaking the engine, so slap in the biggest blower cams you can find.

Change diff ratio from std 3.66 to 4.1

Changing a diff can help, however WEIGHT (loss of mass) will have a bigger impact on acceleration as Force = mass × acceleration. Therefore reducing mass will allow faster acceleration for the same amount of force.

These calcs are based on my car's torque curve.
Acceleration (6,250 rpm, 1.646 gearbox ratio, 4.1 dif)
1100 kg = 3.83 m/s2
1000 kg = 4.21 m/s2
_900 kg = 4.68 m/s2

The extra 200kg equates to 4.25m over 5 secs.

Acceleration (6,250 rpm, 1.646 gearbox ratio, 4.3 dif)
1100 kg = 4.02 m/s2
1000 kg = 4.42 m/s2
_900 kg = 4.91 m/s2

The extra 200kg equates to 4.45m over 5 secs

You would need a combination of weight reduction, diff ratio change and Dann's suggestions to get a noticeable change. In addition I would add swapping to E85 as this will allow a wider option in the tune to get more power where you want it, mid range.

What has Moto-East suggested?

Magpie wrote:Changing a diff can help, however WEIGHT (loss of mass) will have a bigger impact on acceleration as Force = mass × acceleration. Therefore reducing mass will allow faster acceleration for the same amount of force.

Weight may well be the better option.

But it's a lot easier to slap in a shorter diff than it is to take out 100kg (if you want to retain many features... if you're OK with gutting the car weight loss becomes easy)

hks_kansei good points

The good thing about weight loss is that it doesn't compromise performance anywhere and improves it everywhere whereas a shorter diff shortens the gears.

The low hanging fruit of weight savings are carbon hardtop (25kg), battery (5kg) and stereo (6kg), I've done all of those savings and felt that It was worthwhile, the stereo is pretty extreme though haha..

While the weight saving doesn't sound like much when you just write it down as numbers like that you need to consider that a stock NB8B is only 18kg lighter than an NC so even a carbon hardtop makes your NC lighter than an NB8B.

Cams are probably a good investment for engine performance, I've got a set sitting around to go in my car after I get some other work done on the engine. Mike from MotoEast publicly talks about the gains of his cams and my tuner has proven gains out of the cams he uses. Since Mike tunes your car I'd ask him about it.

For really big improvements a 2.5L engine or a Fab9 turbo kit would probably be the move but that is $$.

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Unfortunately weight loss only option is trimming down the driver. Car is roadster and exhaust fully done and running Enkei RPF1 wheels.

Thanks guys for the suggestions. I had the 4:1 diff in the car when it was putting out 120 kw atw and found myself hitting the rev limiter far too often.

Surprised noone has mentioned lightened flywheel.

Will let u know what I decide.

First thoughts are to contact Mike at Moto East again and see if he thinks there are any gains to be made. If Mike is too busy Jay from Tuning Done right is an option.

Novice1

Novice1 wrote:Surprised noone has mentioned lightened flywheel.

You asked for stuff that will make an appreciable difference.

How much lighter is the flywheel? It will make the engine a little more free revving but not what you are looking for on its own.

Magpie wrote:How much lighter is the flywheel? It will make the engine a little more free revving but not what you are looking for on its own.

Same flywheel as in Danny,s NC x5 plus.

No idea re weight difference.

Novive1

In the words of the guy who built my Evo - 'how fast do you want to spend'?

Have you considered a 2.5L swap? I know you don't want to build the engine but just dropping one in without building the increase in torque will be huge and I think for $/results it's likely going to yield the best outcome.

This thread on the Miata forums makes it look like a good combo http://forum.miata.net/vb/showthread.php?t=556444

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Novice1 wrote:I am seeking quicker acceleration without going build engine internals.

This excludes an engine swap as well as possibly changing boost levels.

I'm assuming that the solution is work with what is already there however changing final drive is an option but custom gearbox ratios are not .

Smaller diameter wheels.

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Magpie wrote:

Novice1 wrote:I am seeking quicker acceleration without going build engine internals.

This excludes an engine swap as well as possibly changing boost levels.

I'm assuming that the solution is work with what is already there however changing final drive is an option but custom gearbox ratios are not .

Yeh I thought that would probably be the case, it will be interesting to see what Mike suggests he does (I'd assume he'll say Cams).

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