Spercharged K20A and Hondata ECU

The Oily Bits Engine Swaps
1

I’ve got a standard K20A in my exige which has been dyno’d at 205bhp. I’d like to increase both torque and bhp and was considering supercharging.
Can anyone tell me the relative merits of the Rotrex Supercharger against the Jackson. The Rotrex seems to be more efficient but needs lots of revs to really perform. The Jackson seems to give more torque at lower revs but ultimately gives less power. An intercooler can be added to the Rotrex but not to the Jackson. Has anyone any experience of the Hondata ECU?

2

Nick

What ECU are you running if not Hondata? Most conversions use the Hondata, including mine, & it appears to be relatively easy to re-map.

The JRSC (ie Eaton) is the tried & tested kit, whilst the Rotrex is still under development. In the real world, I very much doubt there will be any perceptible difference in performance between the two, although comparative dyno testing will no doubt show up the divergences. I find it difficult to envisage ever needing more than 300bhp in an Exige, but perhaps that’s cos I’m a crap driver!

There is an Exige presently being fitted with the Rotrex, & it will be interesting to see how the intercooler is installed.

3

Maidstone Sports Cars carried out my conversion and they’ve done a great job but apparently don’t use the hondata.

4

Maidstone Sports Cars carried out my conversion and they’ve done a great job but apparently don’t use the hondata.

Since when, Nick, cos they used to?

5

If I recall correctly Andrew Marsh advised me when I was considering having the conversion some 6 months or so ago. But I would’nt know what one looked like anyway.

6

If I recall correctly Andrew Marsh advised me when I was considering having the conversion some 6 months or so ago. But I would’nt know what one looked like anyway.

I’d be very suprised if it didn’t.

Andrew will fit the JRSC for around �3k for you. This takes the car to another league.

The Rotrex is pretty much untested as yet. And to bear in mind - if you do go for the rotrex then the higher power will mean it’d be necessary to crack the engine to strengthen the bottom end etc.

Pesky speaks the truth. 300 on 225 rubber is a lot.

HTH

7

I could be wrong but I believe the Maidstone kit uses a Hondata but not the full blown K-Pro as they have specific maps for each set-up.

There is a thread on SELOC at the moment about Superchargers that may be of interest.

8

MSC use Hondata K-100’s by default, K-Pro is an option (which I have).
Also the only dyno print ive seen showed 223bhp on a UK K20A2 engine, here it is infact.
http://www.dyno-plot.co.uk/dyno/dynoplot/id%3D3%26sort%3Deng%26but_sea%3Dqs%26sea_simple%3Dlink+up/Lotus-Elise-Link-up.htm

Christian

9

Mine was a dyno test at Surrey Rolling road. They also adjust for temp so the results do not vary day by day. This adjustment, -9 bhp, is included in the 205bhp.

The fuel map shows up as a bit irregular which may explain the lower power which I’m going to check out with MSC.

How do you find the Hondata pro? Who does you’re mapping?

10

nick

its not only about temperature here i don’t think… barometric pressure and air density will also vary day-to-day… so i’m not sure a simple compensation for temp will be meaningful… will it ?

11

There is an Exige presently being fitted with the Rotrex, & it will be interesting to see how the intercooler is installed.

Just had a gander at the Rotrex web page and they are original equipment to both:

Freestream Cars ; and

Koenigsegg

One of the two listed UK dealers have photos of the kit fitted to a Honda car engine:

[image]http://www.tts-performance.com/catalog/images/ttssuper/typerinstallation.jpg[/image] [image]http://www.tts-performance.com/catalog/images/ttssuper/typerinstallation2.jpg[/image]

[image]http://www.tts-performance.com/catalog/images/ttssuper/typercomp.jpg[/image] [image]http://www.tts-performance.com/catalog/images/ttssuper/typer_torque.jpg[/image]

and interestingly states: “Introducing nitrous oxide into the supercharged engine has the effect of cooling the intake charge temperature, reducing the effect of knocking and at the same time increasing BHP. An excellent combination.”

12

Steve

See “Anglesey” thread

13

I went by TTS yesterday, I was looking for an ex Cosworth colleague who’s set up a new dyno centre with them at Silverstone. I couldn’t find him (Chris Rapps?) but I did spot a couple of Rotrex equipped CTRs with their front bumpers off. The intercoolers were pretty big(~ 80025060mm). I think they’re planning an Elise drag racer with this lump… Its early days for my car but Chris did say he’s been doing a lot of development on the Civic and he loves it. He finds the Hondata ECU really nice to use. I would post his direct number but he’s got it wrong on his business card and I got thru to an equestrian centre - we need more than one horsepower though… I think TTS will take some beating on this one.

For the intercooler I think you’ll need to go to air-water-air with a sexy heat exchanger unit in the back linked up to a low temp rad in the nose. We’ve been running the 300BHP Audi Grinall like this and it works well.

BC

14

MSC use Hondata K-100’s by default, K-Pro is an option (which I have).
Also the only dyno print ive seen showed 223bhp on a UK K20A2 engine, here it is infact.
http://www.dyno-plot.co.uk/dyno/dynoplot/id%3D3%26sort%3Deng%26but_sea%3Dqs%26sea_simple%3Dlink+up/Lotus-Elise-Link-up.htm

Christian

Just out of interest do these figures represent power at the wheels or flywheel?

15

Those are flywheel measurments (projected anyway)