SeanStone
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| posted on 21/1/11 at 09:22 AM |
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S2000 bike carb selection and engine management
Was wondering which bike card would be most suitable as throttle bodies are extremely expensive! I presume emerald would be the cheapest aftermarket
management?
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daniel mason
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| posted on 21/1/11 at 09:35 AM |
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Does your f20c not have single throttle body? Aem ecu's are plug and play and available on s2000 forum. That's where I got mine from
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SeanStone
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| posted on 21/1/11 at 09:51 AM |
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what does the aem ecu allow you to do? How much is it?
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SPYDER
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| posted on 21/1/11 at 10:16 AM |
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Hi there.
If you take the well known Weber choke selection diagram as a guide it would suggest a choke size of around 46- 47mm for a 2litre engine peaking at
8300 rpm.
I don't know of a superbike carb of this size.
Since bikes are now exclusively fuel injected you would be looking at older superbikes.
Early Honda Blackbird are 42mm. There might be some larger than those but I don't know of any.
According to the Weber chart these would not allow peak power on your engine although I think that you wouldn't lose much.
If you reconsider the FI route you could possibly use two sets of Aprilia throttle bodies which I think are 48mm.
They are cheap too. And have twin injectors IIRC.
Using four 48mm throttle bodies would release the full power potential of your engine but would need a carefully planned throttle linkage to give
smooth progression at low openings.
If you on a strict budget I would suggest the Blackbird carbs although these might need to be mounted at an upward angle which will increase total
height.
I assume there is a reason not to be using the standard plenum???
Pic is of a set of Blackbird carbs on a CNC manifold I made to suit 3SGE Toyota engine.
Geoff
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SeanStone
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| posted on 21/1/11 at 10:19 AM |
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I'll end up with more power with the carbs on when mapped, it will sound a lot better too!
If it is likely to be detrimental then sticking with the plenum until a decent throttle body kit can be bought then sticking with the standard plenum
won't be a problem
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omega0684
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| posted on 21/1/11 at 11:01 AM |
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quote:
Originally posted by SeanStone
I'll end up with more power with the carbs on when mapped, it will sound a lot better too!
If it is likely to be detrimental then sticking with the plenum until a decent throttle body kit can be bought then sticking with the standard plenum
won't be a problem
excuse my naievity, but how will you end up with more power running carbs with smaller butterflies than running an EFI system with Larger butterflies?
I love Pinto's, even if i did get mine from P&O!
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SeanStone
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| posted on 21/1/11 at 11:08 AM |
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I was under the impression that giving each cylinder it's own optimised airflow would allow greater power to be achieved. I also thought that
bike carbs could be used as a throttle body while stil being able to use a fuel rail to keep the fuel injection.
Have I missed something? 
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SPYDER
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| posted on 21/1/11 at 11:52 AM |
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I would have thought that Mr. Honda has already optimised the airflow somewhat in order to achieve nearly 240hp from two litres. There can't be
much wrong with the standard system. Far from it.
Take a look on the forums and see if a larger single butterfly yields any benefits.
Other than that I would keep it standard if possible. The car should be quick enough.
If the car is going to be used mainly on the track then I might consider the Aprilia throttle body conversion which might yield a power increase,
particularly if the rev limit could be raised.
Throttle control on the road might be compromised though, chiefly at lower openings.
Geoff
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Richard Quinn
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| posted on 21/1/11 at 12:05 PM |
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quote:
Originally posted by SPYDER
you could possibly use two sets of Aprilia throttle bodies which I think are 48mm.
They are cheap too. And have twin injectors IIRC.
Early ones were 52mm and the later ones were 57mm. They were both single injector setups. The RSV4 has twin injectors but I'm not sure what size
the bodies are (and they would be harder to come by as the RSV4 is fetching top dollar)
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SeanStone
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| posted on 21/1/11 at 12:06 PM |
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Well the race engineering design throttle body and ecu kit gets it to about 270hp and about 20nm more torque. So there are improvements to be made!
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SPYDER
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| posted on 21/1/11 at 12:27 PM |
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Quote from Race Engineering website....
"This engine is an excellent basis for a good strong, powerful high revving reliable 2ltr engine. A standard Honda unit gives around 230 BHP @
8500RPM. With a Throttle body kit, our ECU and an EXHAUST we can achieve 255BHP @ 9000RPM with 175 FTLBS of TORQUE. "
The 270hp kit is based on a 2.3 litre conversion.
There is undoubtedly room for improvement but possibly not in a locost way. The 255hp kit will probably be £3K.
I would check out the large single body route, or try to find 48mm bike throttle bodies as the next alternative.
Using carbs purely as butterflies is do-able but still leaves you searching out suitably sized ones.
Geoff.
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daniel mason
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| posted on 21/1/11 at 01:29 PM |
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why would you want to buy some carbs when you already have the throttle body? i dont get it. join the s2000 forum and ask on there.they know there
stuff where the f20c is concerned. carbs would be a waste of time!
the aem unit was £400 second hand,but you dont need a loom as it uses honda plugs and everything. the engine loom just plugs directly into the unit.
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scootz
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| posted on 21/1/11 at 01:31 PM |
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quote:
Originally posted by SPYDER
I would have thought that Mr. Honda has already optimised the airflow somewhat in order to achieve nearly 240hp from two litres...
I guess he did, but he also had to concern himself with emissions and 'stuff'.
It's Evolution Baby!
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SPYDER
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| posted on 21/1/11 at 02:14 PM |
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Sean, is your car for the road or for trackdays etc?
Have you been on the s2000 forums?
Ask about induction kits. It may give a locost power increase.
Only maybe though.
I can only imagine how quick an S2000 Locost will be.
My 3SGE engined car has nearly 170hp and is reasonably nippy despite not being the lightest seven type.
Plenty quick enough for road use I would say. IMHO
If you've got the standard ECU etc. why not fit that to start with?
Geoff.
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daniel mason
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| posted on 21/1/11 at 03:34 PM |
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It's difficult to sort with original ecu. Although some have done it! There is loads of wiring to sort/ bypass for the original unit to work.
And they are not programmable. Exhaust is totally different also so it would benefit from a re map. There is no point spending loads on a great engine
and not maximising it's potential. You need a good exhaust. I am modifying a buddyclub. A good induction kit, I am using the prm cai. and a
mappable ecu, I went for aem for ease of wiring. All of these were bought second hand from s2ki for under £700 so it can be done
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SeanStone
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| posted on 21/1/11 at 03:49 PM |
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thanks for your input guys 
i think i'll save tuning for after it's been built. an aftermarket ecu does seem to be the simplest way of going about things. If any of
your ever hear of an aem ecu going cheap, let me know (if you remember); i'll be keeping an eye out!
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daniel mason
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| posted on 21/1/11 at 04:56 PM |
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Join s2000 forum mate there is loads of units for sale which are specific to the s2000. Mugen. J's racing, spoon, aem
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SeanStone
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| posted on 21/1/11 at 05:02 PM |
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Joined, thanks
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matt_gsxr
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| posted on 24/1/11 at 05:31 PM |
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which is a decent s2000 UK based forum? I am after some stock injectors and don't know where to ask.
It seems that these things don't end up on e-bay
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atomic
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| posted on 26/1/11 at 01:42 PM |
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Don't bother with the AEM as there are far better units out there for a similar price. The original AEM unit was designed for them by GEMS and
the GEMS EM36 is very similar but has a better interface that the Series 1 AEM (no experience of the S2).
I believe I was the second person in the UK to install a F20C into a Seven (after Blink Motorsport) and I chose the EFI Technology srl Euro-4 ecu. EFI
now have a cheaper version called the Euro-2 which will do everything you need and much, much more. The software was designed specifically for/with
V-Tec in-mind in collaboration with OBR and Mugen Honda. EFI Technology srl supply direct to Honda for development ecu's and Honda Motorsport
(which is run by JAS Motorsport) so you know they are top quality. ECU's with similar capabilities to the EFI ones are the Bosch MS4 Sport,
Magneti Marelli SRA.Ex and Motec M600/800 and the Pactel SQ6 all of which use cost options to unlock features that are standard on the EFI's and
when you factor in this they end up costing 2/3 times as much.
I am currently running ATPower Throttle Bodies and am eagerly awaiting their new drive-by-wire version so I can add auto throttle blipping.
With regards to injectors, if you are requiring a new set I would recommend the Honda RDX 410cc injectors with the OBD2 11mm Adapters. You can get a
full kit from the us very cheap
http://www.xenocron.com/injectors-rdx-injectors-c-30_98.html?osCsid=c364f50e37f9d47d0b0ecaaf13a56651
[Edited on 28/1/11 by atomic]
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matt_gsxr
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| posted on 26/1/11 at 02:16 PM |
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Thanks for that tip on the injectors.
those ones look like this
My ones look like this (civic left fits fine, gsxr1000 fits fine, different length)
I understand that I need a kit for the inflow end of these, and that the connectors are different, no problem there.
But at the TBI end of things, do I just swap the thick rubber washer over, or is there some other adapter that I need?
Thanks for your help with this,
Matt
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daniel mason
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| posted on 26/1/11 at 06:29 PM |
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i agre there are probably better units than the AEM, but its a question of cost also.the unit i have does everything i need it to and the engine loom
connects direct to unit. and it was under £400, (second hand)
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