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Phil S1

A Tale Of Two Manifolds, Two Throttle Bodies And Two Rolling Roads.

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Some of you may remember, back in 2013, I made a number of performance mods to my car, as detailed here:-

 

http://www.midlandslotus.co.uk/forum/topic/61646-emerald-installation-and-rolling-road-mapping/

 

The resultant spec at that point, from inlet through to exhaust, was as follows:-

  • Standard airbox modified to receive a 100mm diameter cold air feed
  • K & N panel filter
  • De-wedged 48mm alloy throttle body
  • VVC plenum

Sabre Heads supplied parts comprising of:-

  • KR1 ported cylinder head
  • Newman Phase 2 cams
  • Turbo Sport Vernier pulleys
  • Emerald K6 ECU

Plus on the exhaust side:-

  • Larini 4-2-1 manifold and link pipe
  • Standard Catalytic converter
  • Larini Club Sport exhaust.

Once fully mapped at Emerald and using V-power fuel I ended up with a more than reasonable 157.0 BHP at 6960 rpm combined with a max torque value of 139.l lbft at 4947 rpm.

On one of my trips to see Roger Fabry at Sabre Heads at that time he commented on the fact that my Larini 4-2-1 manifold was in fact a large bore manifold, better suited to 200+BHP applications than my own. I had bought the Larini some years earlier and at that time it was the only one they produced, unlike today when they now sell both large and small bore manifolds. So up till then I was none the wiser. Given the expense I had already incurred at that time with all the aforementioned mods I decided to stick with it anyway and see how it went.

 

It went pretty well all in all but the following year I started to tire of the additional noise the overall combination of mods had introduced so chose to swap out the Larini Club Sport exhaust for the Larini Sports exhaust with extra silencing. This I found much more appealing to my ageing ears, on the downside though it was considerably heavier.

 

Then, earlier this year I also decided to dispense with the de-wedged throttle body. It was fine when you were ‘on it’ but in everyday traffic the slightly ‘hair-trigger’ effect, brought about the removal of the wedge, became rather tiresome. I therefore decided to revert back to my standard 48mm alloy throttle body instead. This instantly felt smooth again but I realised this particular mod was going to ultimately require some re-mapping to let the Emerald ECU know there wasn’t going to be as much air flowing in as there once was.

 

Mapping sessions aren’t cheap so I thought - What else am I likely to want to change? Answer – I really need a small bore 4-2-1 manifold. A few emails and phone call to Roger later and a very reasonably priced Piper small bore 4-2-1 manifold and link pipe was winging its way to me.

Here’s a few photos showing the differences.

Larini on the left and Piper on the right:-

 

IMG_20160923_184355762_zpsciudumtz.jpg

 

and vice-versa:-

 

IMG_20160923_184217361_zpstxgf2ffe.jpg

 

You can probably see in the above photo that the bores on the Larini were so large that Roger had previously arranged to have them locally built up with weld to ensure a good sealing face with the head.

The bores of the Larini measured around 42mm:-

 

IMG_20160923_184724510_zps6gwrhmwy.jpg

 

 whereas those of the Piper measure around 38,50mm:-

 

IMG_20160923_184901026_zps2pwrbz3i.jpg

 

My old Larini has now incidentally already found itself a new home already, soon to be fitted to a hillclimbing S1 Exige in France. (Funds from the sale of that and my de-wedged throttle body also happened to nicely cover the cost for mapping).

 

The Piper manifold is listed as being for the S2 Elise and I believe these brackets are to secure the heat shielding when used in that application:-

 

IMG_20160923_185423840_zpsiz4sfar6.jpg

 

For the S1, they are not required since the heat shielding is mounted differently. The brackets didn’t affect the installation in the S1 so I guess I could have cut them off and saved a bit of weight there but never mind smile.png

 

For those not familiar with fitting a 4-2-1 manifold, apart from removing the undertray obviously, you’ll also need to remove the heat shielding and oil filter. Don’t forget to disconnect the battery too or you run the risk of shorting it out across the alternator terminals whilst wrestling with the manifold. It also makes life a lot easier if you disconnect the bottom engine mount. Doing so allows the engine to be levered away from the bulkhead, providing more clearance when feeding the manifold up and into position.

 

Whilst removing the bottom engine mount I took the opportunity to clean up the sump bracket that I’d not got round to previously. Once removed, I cleaned it up and gave it a fresh coat of black paint, looks much better now:-

 

IMG_20160924_095940195_zps5rqg4ltt.jpg

 

With the new manifold fitted it was time to get the car back on a rolling road. Previously I had taken my car to Emerald themselves at Watton near Norwich who did a great job but I didn’t particularly relish the thought of the journey there and back again, particularly at this time of year. A few people on MLOC have recently used DynoTech at Ripley, Martin R for one, and rated the job they do there.

http://www.dynoremapping.co.uk/

Since they are on my doorstep it seemed the obvious choice.

 

I called by one afternoon and had a chat with Kev, explained what I had done and that I was looking for good driveability more than anything. He seemed to know his stuff and I subsequently booked the car in. There was around a two week waiting list at the time so business seems good.

I dropped the car off for opening time at 8.30am. Due to other commitments I was unable to stay there with the car so awaited a phone call later that afternoon. Phone call received I headed back, had a look at my new performance figures (which were surprising) and then Kev asked me to take him out for a test drive. This was with his laptop still plugged in to ensure all was well and that I was happy with how the car was behaving. The heavens had decided to open and the afternoon traffic didn’t make for the ideal test drive but nonetheless, driveability was fine and the engine was particularly lively. I had hoped for more torque and I’d certainly got it. There was a noticeable surge at around 3000rpm and again further up the rev range but conditions just weren’t right to exploit it to its full potential. I paid my dues and had a lively drive back home.

 

All that remained then was to re-fit the undertray. (I had left it off purposefully for the rolling road session, it helps with finding suitable points to anchor the car down and aids cooling). The Piper manifold downpipes sit a little lower than the Larini did previously so I had to cut a little more of the undertray away around the keyhole slot and chamfer a corner off one of the NACA ducts but that aside fitting was pretty straight forward all in all. It also helped this time having the proper tool for swapping the lambda sensor over from one manifold to the other smile.png

 

So what about the rolling road figures I hear you ask?

 

Here’s the figures from before at Emerald with the Larini large bore manifold and a de-wedged throttle body

 

157 BHP and 139.1 lbft :-

Emerald-RR-Result27Mar2014_zps092b4885.j

 

And here’s the figures from DynoTech with the Piper small bore manifold and a standard 48mm throttle body

 

170.1 BHP and 150 lbft :-

 

Power%20v%20Torque_zpszwhfkzik.jpg

 

Plus a separate AFR graph:-

 

Power%20v%20AFR_zpsd5ejzplq.jpg

 

 

And here’s an overlay I've made of the two, showing where the differences occur:-

 

RR%20Comparison_zps1pjw1xot.jpg

So there you have it, more torque over most of the rev range and 170BHP! This is a figure not even Roger has seen previously with this suite of mods so there may well be some variation between the DynoTech rolling road and that of Emerald.

I had been expecting to lose a little power by removing the de-wedged throttle body but that certainly does not seem to have been the case. And the max power is now achieved at just 6250rpm rather than 7000rpm previously.

I had been hoping for more torque from the Piper and that certainly is the case with increases at 3250rpm and again at 5000rpm.

 

All in all, a great result, albeit not quite the result I had been expecting smile.png

 

Thanks to Kev at DynoTech and a big thanks as always to Roger at Sabre Heads thumbs_up.gif

http://www.sabre-heads.co.uk/1.html

 

 

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Wow! That's fantastic news mate. And a great write up.

It's food for thought. I might ask Dyno Tech to put mine on the rollers to see what the new engine is making.

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Phil, good work. Rog always does say a small bore manifold improves the torque a lot in all but the big power K. I have gone from a big bore to a EP on mine. It seems livelier. We need a rolling road day or evening. We must arrange one. 

 

Where did we do the one with Marcus?

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Great stuff Phil :)

 

I too have recently fitted a small bore piper manifold but a solid version which was as typical interesting to install!

 

Martin offered me it after trying a large bore janspeed exhaust from Kurt which turned the engine power her flat.

 

It took me awhile to install but as you mention Phil it's now a monster even with a moderate 135 cam install with no head work and std pullies it used to go well now t goes very well ;)

 

I've not rolling roaded mine yet.

 

Martin we went to Dyno Daze in Hinkley which is a good place although mine prob won't fit on now with the front splitter.

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If i get a chance i will give them a buzz   :)

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Phil you running a Cat??

 

 

Good figures!

 

I'm thinking of turning down my elise too as also road use only now and the 52mm throttle body is a bloody nightmare in traffic sometimes, near stall followed by loads of revs! Haha!

 

Also want it easier each year for the MOT as finding friendly MOT stations these days is tougher.

 

Not sure if I'll need cam timing doing too to get it to pass MOT, or whether it can just be done on the fuel map...Answers on a postcard....Martin???

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Stu, i must have a standard ally 48mm TB somewhere if you want one? If you run an emerald you can have an MOT map at probably about 14.7 AFR?

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Phil you running a Cat??

 

 

Good figures!

 

I'm thinking of turning down my elise too as also road use only now and the 52mm throttle body is a bloody nightmare in traffic sometimes, near stall followed by loads of revs! Haha!

 

Also want it easier each year for the MOT as finding friendly MOT stations these days is tougher.

 

Not sure if I'll need cam timing doing too to get it to pass MOT, or whether it can just be done on the fuel map...Answers on a postcard....Martin???

Stu PM me I can help on the MOT front

Very good write up phil. The piper small bore exhausts are brilliant! Very impressive figures.

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Phil you running a Cat??

 

 

Good figures!

 

I'm thinking of turning down my elise too as also road use only now and the 52mm throttle body is a bloody nightmare in traffic sometimes, near stall followed by loads of revs! Haha!

 

Also want it easier each year for the MOT as finding friendly MOT stations these days is tougher.

 

Not sure if I'll need cam timing doing too to get it to pass MOT, or whether it can just be done on the fuel map...Answers on a postcard....Martin???

Hi Stu, yes I've always run with a standard cat but still had problems with the emissions on occasion. My MOT is due so I'll see how I get on this time.

 

Thanks for all the positive replies guys. Could be interested in a rolling road day sometime to see how mine compares and whether the figures are repeatable smile.png

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Stu, i must have a standard ally 48mm TB somewhere if you want one? If you run an emerald you can have an MOT map at probably about 14.7 AFR?

 

 

 

Hi Martin, I have the original I took off somewhere.......Not sure where, but, its on the house somewhere... If I've been in it a lot actually get used to it again and get smoother with it, jumping from a diesel auto van to the elise is quite a change of drive. Went out on Sat for a blast round the peaks and fell in love again with the elsie. New tyres made a huge difference. Rest of car really tired looking now. 

 

Last map I had makes it drive really nice and smooth, but, think its pretty rich as the zorst is sooty, where before after a good thrashing it was like virgin steel. I think what I'm looking for is a compromise map that is road legal and can run a cat and deal with the odd track day.

 

Getting a bit bored having to find friendly garages / remapping / popping cats in and taking them out once a year etc. Had car for nearly 10 years now and the annual faff is annoying!! Lol!

 

Alex B I'll pm you....!

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Hi Martin, I have the original I took off somewhere.......Not sure where, but, its on the house somewhere... If I've been in it a lot actually get used to it again and get smoother with it, jumping from a diesel auto van to the elise is quite a change of drive. Went out on Sat for a blast round the peaks and fell in love again with the elsie. New tyres made a huge difference. Rest of car really tired looking now. 

 

Last map I had makes it drive really nice and smooth, but, think its pretty rich as the zorst is sooty, where before after a good thrashing it was like virgin steel. I think what I'm looking for is a compromise map that is road legal and can run a cat and deal with the odd track day.

 

Getting a bit bored having to find friendly garages / remapping / popping cats in and taking them out once a year etc. Had car for nearly 10 years now and the annual faff is annoying!! Lol!

 

Alex B I'll pm you....!

Just had mine MOT'd this afternoon Stu, I had really struggled last year so asked DynoTech to ensure this latest mapping would be MOT compliant and I'm pleased to say it went through first time smile.png

 

The figures were as follows:-

 

Fast Idle Test:                                                           PASS

Engine Speed      2500-3000rpm      2755rpm           PASS

CO                       Max 0.20%            0.00%               PASS

HC                       Max 200 ppm        7 ppm               PASS

Lambda               0.97-1.03              1.03                   PASS

                                               

Natural Idle Test:                                                      PASS

Engine Speed      450-1500 rpm       750 rpm            PASS

CO                       Max 0.30%            0.00%               PASS

Overall Result:   Basic Emission Test Result:       PASS

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