My MY11 Evora S; the next chapter(s).

[Bravo73]

I have now had my MY11 Evora S for nearly a year and we all know what wonderful cars they are. I have done a few, minor interior mods (steering wheel, gear knob & gator) to help match the interior to the SR exterior. However, it's now time to do some more significant mods in order to get the V6 breathing more easily. My long term intention is to update the airflow, all the way from the intake, through the manifolds, cats and then out of the backbox/silencer. I intend to try and run a powercheck before each section is added, in order to serve as some sort of reference to which mods actually help with the power delivery and which are more, er, 'cosmetic'.

So, with this in mind, this box arrived a few days ago:

 

The contents are currently being fitted so, hopefully, I will be able to pick up my car later today. However, here is a little teaser as to it's contents:

[JayEmm]

Tidy

[PaulCP]

Looking forward to your views on the difference on the 22nd at Snetterton 

Is Dave doing the work for you?

 

[theelanman]

ah!!!....a cup holder......

lol

seriously tho' which komotec bit is that?

[Bravo73]

16 minutes ago, PaulCP said:

Is Dave doing the work for you?

He would be if a) his dyno was operational by now and b) he returned my calls! Hangar111's dyno isn't quite operational yet either.

So, this first stage is being done in town at a well regarded dyno operator, Clive Atthowe.

13 minutes ago, theelanman said:

seriously tho' which komotec bit is that?

All to be revealed later today (I hope).

[Colin G]

Am I the only person that's a bit irked by how they've tacked their nameplate on to what is no doubt an expensive item?

 

[theelanman]

its not the best........

I wouldn't have sent it out like that......

just a cheap way of doing it I guess........laser etched plate that can be tack welded onto anything

[CocoPops]

Maybe they don't make it?

They just stick their name on it before sending out of the door?

[theelanman]

what....????......outsourcing to china........surely not.......lol

[CocoPops]

3 minutes ago, theelanman said:

what....????......outsourcing to china........surely not.......lol

I know!! Outrageous!

German built is MUCH better than China

Anyway, back on topic!

Is it a valved system? Sound/video clips please

 

[Bravo73]

Well, no prizes for guessing what was in the box. A Komotec valved silencer/backbox:

 

So, my car went from this:

...to this:

 

So, what are my first impressions? Hmmm, I guess that unfortunately I'm slightly underwhelmed. It was chucking it down for most of today so I didn't really get a chance to test it properly however, in essence, the sound does't seem to be that much different to the MY11 OEM box. It is definitely a different type of sound (slightly more raspy) but, at a guess, the volume is much the same. There also doesn't seem to be as significant a difference between the valve open & closed sound. There is definitely a difference but it is much more subtle than the OEM system. However, the Komotec definitely wins on weight. According to the Komotec figures, it saves 2.7kg.

So, what about the important numbers? Firstly, I must stress that I wasn't expecting the silencer to produce much (if any) performance improvement. Those will come from the intake, manifolds and cats. I was also hoping that Clive would produce a 'before' and 'after' graph to make the comparison obvious. Instead, he plotted all 3 lines on the same graph (OEM/stock: blue, Komotec with sport off: red and Komotec with sport on: orange).

So, what can we deduce? Well, by looking at the 'headline' figures only (Engine BHP), then as stock, my car was putting out a similar figure to lots of other Evora S: 316bhp (obviously well below the quoted Lotus figures of 345bhp). The Komotec improved things ever so slightly: 318bhp with the sport button off. However, the calculated figure with the sport button on was ever so slightly lower: 315bhp (although the wheel figure was ever so slightly higher. The correction factor was obviously different though).

I'll report back in a few days once the exhaust has had a chance to settle in a bit. I suspect the sound might change once it has heated up and cooled down a few times.

A couple of further thoughts. The twin pipes definitely look better than the OEM pig's snout. However, the pipes seem to stick out quite a bit more (in line with the diffuser):

Maybe they fit flusher on the Exige but, to be honest, I'm not wild about how much they stick out.

And finally, you can't deny how practical an Evora is!

 

 

Oh, re a sound file or video: it was way too wet to think about that today. I don't have a GoPro (or equivalent) but once I've worked out how I'm going to do it, I'll try to post something up.

[JayEmm]

Less than 320bhp at the flywheel? Blimey, that is pretty poor for a 3.5l FI motor...

[CocoPops]

Maybe your car is actually down on power Jonny? Might explain the lack of any gap at Snetterton last year? (Ignoring the fact you were on decent tyres and my NA was on normally Pirelli).

Worth investigating further?

[Whitey]

Yellow ones are always faster 

[C8RKH]

I do think the twin exhausts look a helluva lot better than the standard S pigs snout Jonny. A nice mod which may deliver more with the other changes you have planned.

[Stuno1]

Great write up! 

 

This is the problem with rolling roads... Maybe not knowing is better! Have to say I'd be pretty annoyed if mine dynod that low at the fly wheel. 

[K666ADM]

This is very interesting thread, very many thanks for taking the time to post it and keep us all updated.

Does seem like a low increase at a slightly lower rpm, but this is on the breathing out - pretty sure a forced induction engine will have greater gains when you help loosen up its resistance on the breathing in; the induction mods will hopefully see the numbers increase - has your car had a service recently? perhaps you can get the numbers up with just a quick plugs, fluids and filter clean.  Then a performance remap that recognises the new additions to ensure you are getting maximum benefit.  Interesting you did not go for induction modification first,  is that because the parts arrived faster for the exhaust?

 

[PaulCP]

Jonny, a couple of thoughts 

The sound may improve after the box has done a few miles. This was certainly the case with the Milteks on the VX where the sound deepened noticeably after around 1000 miles.

Re the power gains, in addition to Adam's thoughts on the induction side, maybe one big restriction is the manifolds with their built in cats. Changing the manifolds, albeit a much more expensive option, would probably show far better results and assist in the sound dept.

[Bravo73]

2 hours ago, CocoPops said:

Maybe your car is actually down on power Jonny? Might explain the lack of any gap at Snetterton last year? (Ignoring the fact you were on decent tyres and my NA was on normally Pirelli).

Worth investigating further?

My car is booked into Motorsports in a couple of weeks time for it's annual service. I'll see what they have to say about it.

(I think that it was only putting out about 100bhp last year. I'm pretty sure it was like that at Snett... ).

 

1 hour ago, Stuno1 said:

This is the problem with rolling roads... Maybe not knowing is better! Have to say I'd be pretty annoyed if mine dynod that low at the fly wheel. 

Get your car on a dyno then! Judging by previous threads, it's not unheard of for Ss to be putting out 315-320bhp.

 

1 hour ago, K666ADM said:

Does seem like a low increase at a slightly lower rpm, but this is on the breathing out - pretty sure a forced induction engine will have greater gains when you help loosen up its resistance on the breathing in; the induction mods will hopefully see the numbers increase - has your car had a service recently? perhaps you can get the numbers up with just a quick plugs, fluids and filter clean.  Then a performance remap that recognises the new additions to ensure you are getting maximum benefit.  Interesting you did not go for induction modification first,  is that because the parts arrived faster for the exhaust?

I am fully aware that the backbox wasn't going to give any performance improvements. It was purely for aural reasons. However, during my brief drive yesterday, there didn't seem to be a significant difference from the OEM system (yet).

I'm planning on doing the mods on a 'bit by bit' basis for a couple of reasons. Firstly, I have a genuine interest to see exactly what each component adds to the system (in terms of performance). There is so much written on forums about the various elements and some of it is based on fact but most of it is based on opinion, feeling or just plain bull. Secondly, it will help to spread the costs out. The backbox (including fitting and power runs) has already cost me £1400. The other elements are only going to get more expensive!

The next stage is an 'interim' intake option - a K&N panel filter. Then after that, manifolds & cats (including a remap, probably). Then, a proper intake. Depending on the numbers produced at this stage, I'll then look at changing the supercharger/crankshaft pulley wheels. By this time, it should be in the region of the Komotec 430bhp kit. FWIW, my target is 400bhp.

 

33 minutes ago, PaulCP said:

The sound may improve after the box has done a few miles. This was certainly the case with the Milteks on the VX where the sound deepened noticeably after around 1000 miles.

Re the power gains, in addition to Adam's thoughts on the induction side, maybe one big restriction is the manifolds with their built in cats. Changing the manifolds, albeit a much more expensive option, would probably show far better results and assist in the sound dept.

Absolutely. Depending on how things go (and cash flow etc), manifolds and cats are planned for either the end of this season or the beginning of next.

[Bravo73]

It's much drier today so I've just been out in the car again. My initial impressions are much the same as yesterday. From inside the car, there isn't a great difference in the volume. The sound has definitely changed to a more metallic rasp when under load but it doesn't sound much louder when driving. But from outside the car? Phooey! There is a big change, both in terms of volume, tone and pitch. It sounds much, much better. Phew.

 

 

On 9 March 2016 at 13:34, CocoPops said:

Is it a valved system? Sound/video clips please

So I thought that I'd try making a recording, using my iPhone 6. All was going well until I pushed the sport button and opened the valve. The iPhone mic couldn't handle the levels so tripped out! So this recording is just with the valve closed. Has anybody any suggestions for making a decent recording using my iPhone? (I don't have a dedicated mic, GoPro or other dedicated audio equipment). I tried moving the iPhone further away but it was still tripping it at about 5 metres!

 

 

 

Komotec 2.m4a

[JayEmm]

Toilet paper in front of iphone mic?

I've found with a few german cars they are so well insulated that sports exhausts can't be felt too much inside the car, until they become unbearably loud and just drone inside the cabin. A window slightly down can help though!

[Bravo73]

22 minutes ago, JayEmm said:

Toilet paper in front of iphone mic?

Thanks for the suggestion. Tried it but no joy.

[quantum2000]

Try turning the iphone around so the mic isn't facing the exhaust, or move it to the side of the car rather than having it at the back

Edited March 10, 2016 by quantum2000

[JayEmm]

21 minutes ago, quantum2000 said:

Try turning the iphone around so the mic isn't facing the exhaust, or move it to the side of the car rather than having it at the back

This

[Bravo73]

Tried both but it's still tripping it for some reason. I'll try other options tomorrow because I think the neighbours are getting a bit bored of my revving the car so much.