Duratec Elise to Motorsport/Exige

[Emiel]

Hi all,

Introduced myself long time ago. Some know me from seloc. As I found lots of information here in the past decade, and I have the window banner of exiges.com on the front, I need to put my car here

After stopping with driving cars on track in 2000 I started driving motorbikes. Fast road, track and the ring. After losing a bunch of mates on and off the ring and mates stopping with trackdays I sold everything and started with cars again.

S2 135R was great but it did not catch me

I made side step to an Evo 6. Some trackdays, the ring and snow tyres in the german mountains later I sold it. Fast and fun but also getting bored.

I wanted an original Exige S1 but I did not want to make a tracktoy our of an original exige s1.

A noble but an idiot mistake as back then they where 18-20k…

So bought the Elise, like pictured below. Lots of osmose and paint chips but with an old Duratec installation that was reliable and worked but was far from optimal. Exhaust header very narrow and lots of heat next to drive shaft, intake that sucked in lots of warm air and very very noisy. Cooling was ok but not perfect.

Picked it up near London, drove it on the train and back home through France, Belgium and into Holland.

Couple of weeks later a trip to the ring.

On my way home I noticed my ears started to have a beep and the passenger had the same fun. Also noticed the lack of power due to heat soak, car peaked at 200km/h.

So it was a fun day but it needed an Exige body and the conversion needed improvement.

Short search made me rent a van and drive to, if remember correctly, to the west midlands to pick up copies of the exige clams with a motorsport roof and engine cover.

Also later bought from him a motorsport rear wing and supports and good to go!

Couple of months later it rolled out of the garage.

And months and months later, with an new used 2l duratec as the first one killed itself (camshaft did not get oil so got stuck) and a full over the subframe 4-2-1 with repackable exhaust, jenvey airbox on the ITB’s, lightweight flywheel and replaced the old nitrons with a fresh set of quantums shocks it was much better to drive on street and track. Had lots of small trips to the Eiffel, visited the ring without doing a lap, toke it to work a couple of times and did some trackdays. Busy times as I was only in Europe a couple of weeks a year, rest I was in the US.

Zolder (one of the many charity days)

Zolder sideways on a different day

Zandvoort

Spa

I found a brand new Duratec 2.5 i4 engine and decided that I first wanted to make the conversion technically 90% as I noticed one of the mounts broke, cooling was not 100% and the oil ran hot on Zandvoort. Not so strange as on one of the days it was close to 40 degrees Celsius. The sea was a better option!

The new Duratec engine. 500cc extra.

[Emiel]

So somewhere in time I installed a PRRT and the biggest laminova I could find to replace the air to oil cooler I installed with the new used 2l engine.

Replaced the radiator and the coolant tank and made some small adjustments to the cooling system. Small details as a brake pipe in the top hose leading to the bottom so that it would never suck air in the system. That did the trick!

Car felt great so another charity run with kids with cancer to drive with them or with their brothers/sisters.

[Emiel]

With winter coming it was time for some more prep work for more power. I noticed that the brakes sometime had a hard time, wanted bigger brake setup at the rear and was not sure with all the kerbs if the bearings would stay alive and replacing them in aluminium hubs had an ending as well.

So I found a deal on S2 hubs, drive shafts, etc. And with my rear S1 hubs being steel they gave me some money to make it interesting.

That would also mean: full suspension refurb.

Bought an AP valve and Lotus motorsport brake cylinder, rear hub for radial brake caliper, lightweight steering arms and the Lotus big brake kit. Also new ball joints and decided to replace the rubber in the arms with the well known bearings.

Used a mate his workshop to spray the wishbones and uprights with glass to clean them

Send the shocks to quantum for a rebuild

[Emiel]

And finished it all up.

Before: (older picture with nitrons)

After:

Test fit of the AP valve:

Bracket I found in Japan(expensive!) to reduce stress on the pedal box. Especially with the motorsport cylinder I wanted to try this but made one with a cheap hardware store solution to make sure it works before we design something proper:

Original:

Simple remake:

Nice end result with great wheels but the test fit of the motorsport splitter was not yet a succes (to low)

[Emiel]

Not much later or at the same time, I cannot remember, I installed an EWP as a secondary pump to make sure that when coming of track or standing in traffic for a long time the engine would have enough coolant flow. Would also help to heat up the oil so win win.

Test fit, replaced it with special bolts so it cannot come lose by vibrations

Worked great! Very pleased with it.

So that was it. Enjoyed the car for some drives and then months before lockdown…
Alternator failed.

Only thing not replaced.
And removing it was a shitty job to do.

So with time constrains I decided to leave the car for the time being as I needed to focus on other stuff.

[Emiel]

So in the last years I had spend much time away from home and I had bought lots of stuff for the conversion to the new 2.5 engine.

Also wanted to go back to the close ratio gearbox that I swapped out when there was an issue with the flywheel that could have been the gearbox as well.

One of the items I ordered was a custom made plated diff. So had the CR gearbox rebuild with steel bearings and the diff placed.

Plate for the sump came in from the US and removal of the heavy balancer shaft

Smaller crank pulley as the original was for 2 belts

New timing chain cover with the correct 2 bolt setup instead of 3

And with the engine mounted making sure the mapping was good for a test drive.

[Emiel]

Little bit more throttle after driving it for half an hour

11 november 2022

Testing the plated diff

11 november 2022

And then… I needed to finish construction on my house as it would come up for sale with me moving 100km further away of my backyard, Track Zolder, to buy a new house and settle with the GF and become a dad!

With a cooling problem (PRRT stuck) I was not able to get the new engine on the papers nor get MOT so car had to go in storage for 6months minimum.

4 weeks ago I pulled it out of storage and now I have to find time to fix the PRRT and get MOT.

Started without problems and did a small run around the block to the trailer (rental)

So with the car home and sleepless nights with a 4 month old boy I could focus on 2 things I was not happy with:

First, Emerald ECU not supporting the variable cam and it is a huge impact on performance. Currently the car is making around 205hp/235nm at the wheels without using variable cam.

Solution is found in a ME442 ECU.
As they are getting 245hp and 290nm from this engine with only a cam upgrade I know what I need to do.
New raceline 50mm ITB instead of 45mm, new ecu and new cam.

Second, I had to mount to engine higher due to the big standard sump.
A raceline wetsump (10 degree angle) will be ordered.

And last: Brake balance. To much front focus.

I still had a spare 308mm disc but no handbrake solution. The handbrake solutions available would not pas MOT here so I started searching for a complete new solution.

And it was found! Tesla/brembo electric handbrake calipers.

Weighing 800grams less per caliper compared to the stock rear calipers and only 500gram more then the wilwood solution it looks to be a nice solution. Removal of the handbrake lever and handbrake cables would also be a nice and clean solution.

Tesla caliper weight: 2543 grams Including brake pads.

To be continued. With still have lots of stuff to do in the new house, career path development and a young boy, I will not have time for a while to work on the car. Should be winter 2023/2024 as I am already planning trackdays in 2024. Besides some laps on the ring with a sold 130i prepped ring toy (diff,m3 arms, 335i brakes, etc) not seen a track in 4-5 years.`

[matt447]

Fantastic read - and a wonderful car!

[thommo]

What a great story.Thanks for bringing it to exiges.com. We love a story . . so keep us posted

[andybond]

Yes! Loving this.

Please, please keep us updated.

[sjw]

Same day at Zandvoort in 2014 with my S2 in the background

[Emiel]

Thanks all!

SJW that is the same day for sure! Pretty hot day.

Remember as during lunch I removed the undertray as I had some coolant on it but it was overflow so mounted a empty coca cola bottle to the overflow hose.

Drove all day with a passenger, as I usually do.

Zandvoort 2014 Lotus on Track

[Emiel]

As it is not an Exige I got these made a couple of weeks ago at Divine handcraft. In black and original “charcoal” kinda colour.

[Emiel]

Quick reply but a big one.

Listed my Duratec 2.5 i4 engine up for sale. Once that is sold my close ratio box with fresh steel caged bearings and plated diff will be up for sale and the full duratec conversion bits (for a 2L engine)

The 2L was a great engine and lasted long and many trackdays before I replaced it with the 2.5. The original conversion has be very reliable it is a great engine but the new conversion is inventing the wheel again and keep throwing money at it.
The 245hp and 275nm at the wheels from an engine very close to k-series weight would have been awesome but with less time on my hands and losing interest in the Duratec….

I bought the 2.5 and already had idea’s about going Honda K20a. And that is what I am going for.

Already contacted Dan from HPE for engine mounts, gearbox cable kit and exhaust.

[keithmanx]

Great thread, thanks for sharing!

[Fonzey]

Good stuff, looking forward to more!

[Emiel]

Bought a K20a2 engine, JDM gearbox, mounts, and lots of bits and pieces without exhaust and driveshafts. Not a full conversion but a good start.

Wil retain the big laminova, catchcan, coolant reservoir and secundary waterpump (ewp) up front.

Rest all duratec bits will be sold separately

Item 1: Duratec 2.5i4 with baffled sump/underdrive pully etc
Item 2: B4BP with steel caged bearings and plated diff.
Item 3: full Duratec 2/2.3 litre conversion kit
Item 4: full over subframe exhaust with repackable silencer (only it not wanted with conversion kit

Have a C4BP gearbox for sale as well and original elise s1 exhaust.

Making room for the Honda.

[Emiel]

Well there is a big update, or perhaps a bigger package on the way. Engine/gearbox/mounts/rear subframe/some bits and pieces.

Will start to clear out the garage next week so I can start with removing everything from the car to make room for the new and do an inventory of all bits and pieces still needed like driveshafts, over subframe exhaust, etc and items that need to be replaced (braided fuel lines, etc)

[andybond]

What were you power goals on the duratec?

[Emiel]

It started to grow. The baseline was 204hp and 235nm at the wheels. i drove that and thought it was great but not fast fast. Then I started to look into VCT as it was not enabled and why the other 2.5 conversions where not using it. Worked with emerald but the ECU only did on/off and not PWM control. It was a bit faster with the seat dyno but not great.

Motorsport electronics stopped with a stand alone VCT controller so that was a dead end.

Found Danst engineering ,great guy to communicate with and knows his way around, he made 245hp/275nm at the wheels with different ecu then emerald, stage 2 VCT cams, arp conrod bolts and 50mm ITB.

Brand new crate engine for 2250gbp is offcourse a wonderfull start but started to walk in some details that made the conversion a question mark cost wise vs performance.

I still think that with 245hp/275nm at the wheels the engine is a winner with K series weight, brand new crate engine, improved oil pump and conrod bearings compared to the 2.0/2.3 litre.
Mount it as low as the honda and COG will be great.

With new job coming up, still renovation work on the house, 7month old boy and some benefits with the honda. (Oem ecu, 6th gear) I decided to save myself some time and buy something that I not need to redesign an engine mount for, lengten the exhaust headers etc.