F4R on bike carbs?

[Gt rob]

This been done yet? just on the bay and came across these:

http://cgi.ebay.co.uk/kit-car-carb-...ps=63&clkid=9127561934003925109#ht_500wt_1156

what would i need to get them to fit and work properly?

 

[Goodj]

someone asked about this not too long ago, I believe the general concencus was it'd be a lot of buggering about for not a lot of result.

IN my mind, NA tuning is winners so dont get knocked towards forced induction by the boost crew, go for the revs!

 

[Gt rob]

if jms can do it im sure i can, it wouldnt be far off the power of throttle bodies surely?

 

[Goodj]

hit the search bar fella, I know this got chatted about recently, maybe there was even some useful responses

 

[Gt rob]

i looked, and the top thread was "gym progress thread"!

 

[Matt@codered]

My f7r is on bike carbs, works really well.
Bike carbs don't go out of tune like weber carbs, and in their design can flow twice the original use capacity.
I.E. A 1000cc bike carb is ok for a 2000cc car engine.
Matt@CRM

 

[scotty2hotty81]

Iirc bike carbs don't work on f4r as they can't flow enough air, but yeah do a search pretty sure it was towards the middle of last year.

 

[Laine_16v]

Id say 36mm isnt enough to satisfy an F4R to its full capabilities.

 

[Gt rob]

whats the diameter of throttle bodies then?

 

[sideways danny]

generally a 45mm butterfly is used for a 2 litre upto 250bhp (very roughly)

 

[MartinR]

if jms can do it im sure i can, it wouldnt be far off the power of throttle bodies surely?

lol this i want to see

 

[sideways danny]

my 2p worth, if you want to do this (I can see the appeal of a DIY build) do bike bodies rather than carbs. You'll have to do something about enigne management anyway to run the ignition, so don't undo 20 years of technology and get rid of the fuel injection

 

[Jonny1*2]

why not just do a TB build? tried and tested to work. Make them work on standard management without any issues and become a hero

 

[sideways danny]

why not just do a TB build? tried and tested to work. Make them work on standard management without any issues and become a hero

standard management route is shite, the well known one was converted to DTA management when it was sold as it was crap to drive except at full throttle

 

[Jonny1*2]

hense the . Gasket kit worked a treat by the way, just fitted it

 

[sideways danny]

excellent Much better than those nasty bosal kits

 

[Gt rob]

id use omex, or megasquirt ecu i think. dont want to spent 2 grand on tbs, bike throttle bodies sound ilke an awesome idea.

 

[sideways danny]

jesus, dont use MS, really bad.

 

[Laine_16v]

Set of ITB's up for sale on C16v at the minute for £800. Knock him to £700. Manifold, ECU and a few other bits (can get the 2nd hand for sure), and it wouldnt be a hugely expensive conversion compared to brand new cost.

 

[Gt rob]

whys that? heard nothing but good things about them if set up/ used correctly

 

[Jonny1*2]

saying that, omex is going to set you back £800 ish, so even with that, it's still going to be close to £2K plus.

 

[Jay Payne]

Bike boddies were my plan for my old track car

 

[sideways danny]

if you want budget, then one of the Canems ECU's i sell to use on Mk1's would do you better than MS by a long way. Laine has one on his F4R's mk1 with throttle bodies and he removed VEMS (megasquirt based) as it was constant grief

 

[Laine_16v]

I still have nightmares about it

 

[Gt rob]

lol, going to start making plans for my second engine now then

 

[Matt@codered]

Bike carb choke size and throttle body size are not comparable, as the throttle body is just a butterfly inside a tube, an air device if you like.....you rely on an injector to supply the fuel.
The Carb is a different animal, is has a choke/venturi making a depression in an air path to draw the fuel through a jet to supply fuel/air mixture.

Dont be fooled into thinking bigger is better, a Weber dcoe45 (45mm side draught carb) still has a smaller sized venturi, so could have a choke size of 34-38mm.
If a Bike can rev to 12,000rpm and not go out of tune, then I'm sure my car at 8,000 with its tiny bike carbs will good to run for a long time to come.
If anyone needs proof on how well these things work, sit in my passenger seat at my next trackday........

 

[Craig.H]

^^do you have more info mate, pics, spec, power?

I'm intrigued!

 

[Dan]

^^ me too please carry on

 

[Adey.]

doesnt cro cro use bike itbs on his car? gives good results

 

[spanishfly]

Personally I don't like bike bodies on cars, there not nice to drive, as many have said there suited to 10k+rpm, something you won't be achieving. The power curve will be awful, nothing until peak power.

 

[Matt@codered]

Its all about the state of tune of the car, my car is fine with bike carbs and very spikey cams.....for example I can be in 5th gear at around 30 mph, stab the throttle to the floor, and it will not spit back or hesitate, and will accelerate smoothy to peak rpm.
My only problem is proper filtration, due to space under the bonnet of my mk1 clio, I have to use sock filters on the road which sometimes restricts the car. For sprint and hill climbs I don't use any filters (Only car on track, so no rocks to suck into the inlet HeHeHe!).

One problem I can see with a F4R conversion is the retention of the inlet cam and its dephaser.

Of course this is all down to the usage of the car, on the road? stay with the original setup. Trackday special on a budget? Bike carbs. Race car on a larger budget? either Bike carbs or expensive jenvey style throttle bodies. Standing around in mcDonalds car parks with chrome cages and flamer kits?.......no comment.

 

[slindborg]

MS isnt that bad.... if you redesign the circuitry as its mostly wrong lol, and give the software a little tweak to make it more OEM than homebrew first principles with fudges. BUT for someone who just wants to fit and calibrate, or take to someone to calibrate, get the one that has the 'best' (for you or the calibrator) user interface as the best can be obtained from it then as with N/A 99% of aftermarket ECU's are all good enough.

As for webers going out of tune, thats a proper old wives tale thats been promulgated round the internet for 15 years lol.
Most of the time people buy shagged webers or set them up wrong to bend the spindles which causes the 'going out of tune' lark. Get a decent condition/rebuilt/new set and have them setup by an old skool fella such as Peter Baldwin and you will have a setup that can cope with being taken out of engine bays and put back in many times with no need for a tweak in over 6 years and many many many trackdays of abuse.

 

[Matt@codered]

I have a MegaJolt system ready to go on my Blue car as the current setup is still using the original inj comp, this is an Ignition only unit.
As for the weber comment, I have a Sunbeam Alpine SV with the Holbay engine, the carbs are a nightmare to keep in tune, bacically down to lack of use, (bless her she only comes out to play a couple of times a year).

 

[slindborg]

I dont like MJ because it uses the Ford Edith (yes a t lol) system which just adds cost and complexity (that you cant control).... would be better off with a microsquirt and direct wasted spark control

We did use the webers all the time for 6 years and they never drifted, no 'special' attention was paid so to speak, just a proper setup to ensure full throttle pedal didnt load the spindles up etc.

 

[Matt@codered]

How do you mean MJ adds cost and complexity? Compared to...? Jenveys.....?
An already built MJ unit is probably still under £100, the scrap yards can provide all the extra parts (EDIS module, ign pack, leads and VR type tdc sensor) apart from a custom 36-1 wheel, probably in the region of £20.
Plus there is already an ign map library on the web.

 

[Cro]

I'd beg to differ about bike carbs being bad to drive or the power all at the top. My curve is a flat line makes awesome torque and great bhp. Inc Omex mapped done all under 1k just by doing the work myself.

The only downside issue I'll give you is that mine makes absolutely sweet fa power after 7100 rpm but hasn't made a difference to me yet, I just change then. That's where my peak is and it drops dramatically after that

 

[skiddusmarkus]

I don't know if its ever been done but aSunny/Pulsar GTiR comes with quad throttle bodies as standard and will flow more than enough for anyones needs.The best bit is you can pick them up very cheaply-probably less than £100 but then obviously you have to make them work.They also have 440cc(enough for around 320 ish bhp) injectors as standard so no need ot be buying new ones.

 

[sideways danny]

I don't know if its ever been done but aSunny/Pulsar GTiR comes with quad throttle bodies as standard and will flow more than enough for anyones needs.The best bit is you can pick them up very cheaply-probably less than £100 but then obviously you have to make them work.They also have 440cc(enough for around 320 ish bhp) injectors as standard so no need ot be buying new ones.

tricky. linkages are very non flexible for adaptive use on other cars, but they are OEM quality parts so maybe worth the work. Toyota 20v stuff is a better bet

pulsar injectors would be useless, they're low impedence

 

[j666bed]

I am just fitting ktr tb's to mine, I looked into different carb options, in my opinion, if you are building yourself, i would stick to a kit that has been developed and tested, other options are possible but with all the bits and pieces needed to get the kit to work i am not sure you will see huge financial savings.

 

[slindborg]

How do you mean MJ adds cost and complexity? Compared to...? Jenveys.....?
An already built MJ unit is probably still under £100, the scrap yards can provide all the extra parts (EDIS module, ign pack, leads and VR type tdc sensor) apart from a custom 36-1 wheel, probably in the region of £20.
Plus there is already an ign map library on the web.

I meant in terms of just buying a microsquirt instead.... more functionality for about £20-30 more of brand new kit plus if you fancy coming into the 90's you can go for fuel injection for the cost of the bodies and injectors rather than having to start again