more power opinions

[Windsurfer]

Hi all, I got a s3 caterham with a zetec 2.0 engine (lsd, dedion, 5spd type 9, jenvey 45mm and omex 500 ecu) the easy bolt-on mods are pretty much done. 

The option of buying a newer caterham and sell this one is pretty much impossible since I live in Canada and they are rare as unicorns here... 

My first reflex is to move to a Duratec engine as I will also move to a newer generation engine.  I've done my research and I think I would prefer a 2.0l rather than a 2.3l and put forged con rods and pistons inside the 2.0l. My goal is somewhere near 250hp. (a pretty high sticker price for 60 more hp, I agree). 

The exhaust and intake will switch side, I am ready for this. 

Here are my questions:

-I have an opportunity to buy a very very low mileage 2.0 duratec and was wondering if you think I could find a map for my Omex 500, if the omex 500 is good enough vs new generation to be able to tune this setup wihout dyno time as I do not have knowlgeable ressources that I know of here. 

-I also tought of supercharging the zetec but I find it expensive and complicated for a 20 years old engine. (maybe I am wrong) 

I've done a few research and I think the project will cost me 7000-8000 pounds. 

I do not think that buying a complete setup in England is a solution since shipping will be ridiculous. 

Not an easy question and I know that is has been discussed before, any opinions are welcome. 

winter is comming and I will have plenty of time to work on the engine :-)

Thanks

 

[aerobod - near CYYC]

Omex 500 ECUs are often used by Locost 7s which also commonly use the Duratec, too, so there may be an initial map available from that community. From a Caterham perspective, MBE ECUs can be purchased from SBD Motorsports (https://sbdmotorsport.co.uk/) with most Duratec configurations available and they can do remote tuning sessions, too.

Overall in Canada there aren't specialist tuners I've come across who deal with Duratecs and aftermarket ECUs.

[Windsurfer]

Hi james, thanks for your answer. I did not know about SBD, very interesting.

 I would be able to find a tuner for duratec but no caterham specific tuner for sure. 

thanks

 

[aerobod - near CYYC]

One issue you may have with the Omex 500 is that as far as I know, it is a wasted spark system with only 2 ignition outputs. This may be a bit of a limitation with the Duratec and Coil-on-Plug ignition where you would normally drive each cylinder independently. Overall the Omex 500 is going to be a bit limited due to processing speed and very basic sensor options, as it is quite dated now. It also doesn't seem to have a cam timing input, either, which is normally used on the Duratec. The modifications needed to your wiring loom to accommodate a different ECU may be a limit on upgrading the ECU, though.

This is based on the documentation here: http://omextechnology.co.uk/500v3.02.pdf

[cobar]

It's not a issue to run wasted spark on a Duratec.  The coolant manifold that attaches to the back of the head is designed to take the wasted spark coil pack used in the earlier Duratecs.  However, I would take a closer look at the capability of the Omex to make sure it has a good feature set that will support future plans.  Things like data logging, multiple map selection,closed-loop self mapping, knock control, tractio control, and cam sensor input for COP and sequential injection are all nice things to have.  Given you will likely need to buy or build a new engine harness, selecting the right ECU now will save you headaches down the road.

One big decision you'll face is cam selection.  I agonized over this as I didn't want to sacrifice too much low end.  I was going from Kent DTEC10s, which are essentially the same as used in the 420 and have a very wide power band.  After much deliberation, I went with the DTEC20s and am happy with that choice.  Still sufficient torque below 3000rpm, but pulls strongly until 8100rpm when the rev limiter kicks in. My engine's peak power is held back by the exhaust which was originally sized for the DTEC10 cams.  On the dyno, horsepower is perfectly flat from 6700-8100rpm when we stopped.  I know someone in the UK with the same cams and pistons, similar head work and a larger exhaust whose dyno plot mirrors mine until 6700 when his continues to climb another 15hp to 240hp.  

Regarding heads, you may need some flow improvements or a head swap to meet your 250hp goal.  The 2.0L Duratecs in the US (and I believe Canada) all have a more restrictive head than the 2004 and later 2.3L.  SBD's site talks about the 2008 and later 2.0L heads being higher flow, but based on casting numbers, that head was not offered in the US on the 2.0L.  However, it does appear to be the same as those later 2.3L heads, which are also referred to as high-port.  

I ran into a number of issues tracking down parts during my rebuild, so it may save you some headaches to read through my build thread on USA7s to grab obscure part numbers you may need.  Feel free to PM me here or on USA7s if you have questions along the way.  https://usa7s.net/ips/topic/12467-20l-duratec-rebuild/

-John

 

 

 

[Windsurfer]

hi john, thanks for sharing your experience. Your build tread is very detailed and informative!

Best regards

[Doc007]

Probably easiest to follow the well trodden path of 420R/R500 engines with MBE ECUs. That way you will have more available support. I'd be VERY happy for someone to correct me but it seems that the 420R has more torque below 4500rpm and the R500 more above this. That makes it more fun out of T-junctions/roundabouts in 420 R form but more mumbo with the R500. 
I have a 420R on a plenum that was a LOT of fun and switched the whole engine for a dry-sumped Cosworth built crate engine on TBs. With 266bhp it's got plenty of go! But the 420R certainly had its own charms.

Either way is Win;Win.

But if you want playful AND power then 2.3l is your friend.

[Windsurfer]

You are right on this. I should add a new ECU on my list for that matter. 

You think the 2.3 will be more playful? My thought were on the 2.0l for playfulness (with the fact that the engine will have cast piston and con rod thus higher rev limit.

Thanks for your comments. :-)

 

[Doc007]

If I could have the low down torque of the 420R and the power of the R500 that would be great. I've seen power traces of a 2.3l and it looked peachy!

[cobar]

Mazda has a forged crank available for the 2.3L that was used in their turbo versions.  So equipped and with forged rods and pistons, a 2.3L can safely spin about as high as a 2.0L using forged rods and pistons but with the standard crank.  Choosing between the two really comes down to your preferences for the shape and height of the torque curve.  Assuming you are building the engine for 250+ hp, if you frequently like to short shift and use torque to get around, you might be happier with the larger engine.  However, if you like to wring the engine to redline at every opportunity and don't mind having to work for it, then you might prefer the 2.0L. 

Another option is a 2.4L Duratec based on an Esslinger short block.(actually 2344cc vs. 2261cc for the 2.3L)  It uses the 2.5L block that is slightly over bored, a forged 2.3L Mazda crank, and Esslinger's custom long rods and pistons.  As configured, it's safe to over 8500rpm.  You could use either the 2.3L head, or the even better flowing 2.5L head, although the latter requires VVT delete for bonnet clearance, and different throttle bodies as the shape of the intake ports are very different. 

[rgrigsby]

If we are talking 2.3l Duratecs then i can definitely recommend that route, I've been running my 250bhp 2.3l since 2005. Its a very different experience to the 2.0l. With more low down torque and reving to 7500rpm on the road it's a very relaxing engine, on track it will still fly up to the rev limit and the extra torque really does make a difference.

The nice thing with a 250bhp 2.3l is that its really not that stressed, its a great all rounder but it depends if you want the mad rush to 8500rpm that you woudl get with similar power on a 2.0l Duratec.

Here's the power graph from my RaceCo built engine running on an Emerald ECU, the dotted line is the original map running on a Raceline exhaust, the solid line is a few years later when I switched to the RaceCo through the bonnet exhaust.

 

[Windsurfer]

thanks all for all your replies! It helps a lot! Esslinger is sure very interesting

I am not completly decided yet but it sure help!

I wish I could be able to test drive one of each engine but it is not possible here. 

Do not hesitate if you have any other ideas!

Best regards

[Windsurfer]

thanks all for all your replies! It helps a lot! Esslinger is sure very interesting

I am not completly decided yet but it sure help!

I wish I could be able to test drive one of each engine but it is not possible here. 

Do not hesitate if you have any other ideas!

Best regards

[Doc007]

I'm curious as to why there is a significant drop off in the torque after to rpm.