M20 individual throttle bodies, whats a reasonable price?

[Turbo-Brown]

Bit of a feeler I guess as this may not be of interest to anyone but here goes anyway:

How much would people consider to be a reasonable price for throttle bodies which fit directly onto the M20 cylinder head?

I've been pretty pleased with the results I've had with mine in terms of razor sharp throttle response so I've been developing them from a production point of view and have had about 80% of the machining work priced up but before I go too much further, I thought I'd see whether it was going to be viable to have them made in terms of numbers.

The basic kit would include 6 throttle bodies, the linkage and fuel rail mountings. The standard fuel rail and FPR would be retained.

I've designed them so that the inlets don't point directly at the servo and also don't point vertically up at the bonnet so people can either use trumpets of their desired length, or run an air box which sits atop the cam cover, although I've yet to look into costs for this.

All bearings are sealed ball bearing units so they're suitable for turbocharging too

Other considerations are an ECU to control the whole lot which Ant is able to supply and map.

If anyone has any thoughts, comments, suggestions or questions then feel free to fire away!

Cheers!

Alex

[chu346]

Good idea, i've been looking into doing this myself but can't be bothered designing and fabricating it from scratch.

You say the basic kit contains 6 throttle bodies, the linkage and fuel rail mountings, what else could be used other than engine management?

As for price, well as cheap as you can with making a profit. The dbilas ones are £1500ish according to there site, but I think that comes with some kind of air box. The problem is that I for one don't know how much it cost to obtain these parts and find it hard to put a price on it.

Your making the kit tell us what you think is a fair price, and we will tell you if we can afford it or not

[Turbo-Brown]

I guess at a pinch you could use the standard injectors, but then you're a bit limited as to the amount of power you can make.

I've got to have a couple more drawings priced up this week and then I'll look into the costs to make an airbox with inlet runners so that I can put a full price together, although the more people that want a set, the lower the price gets.

[e21Jason]

Hi

I had a one of manild made to take a complete e36 m3 set of throttle bodies, to go into prfooduction would of been £500.00 a manifold, then you have the cost of the throttlebody set up.

You can get a webber manifold for about £400, but the jenvy's are abourt £200. So i think you would want to be near the £1000 mark.

After messign around with my set up i thought the best idea would be to get to sets o motorbike throttle bodies, drop on throttle off each set and fab up a manifold to take the bike throttles

Jason

[Turbo-Brown]

Haven't managed to find a price for weber manifolds yet, and at any rate they all seem (from the piccies I've seen) to point the inlets at things like the servo or bonnet!

Just had a look on Jenvey's site and a set of 40mm TBs is 3x£205 each, with the linkage being about £100 odd by the looks of it, then there are the fuel rails to buy at £100, fuel pressure regulator housing for around £40, a fuel pressure reg (say) £40 although that's a guess, trumpets which would need to be the curved ones to get anywhere near a decent tract length so that's 6x£37, and then there's the manifold at about £400.

So all that comes to: £1517, Plus vat comes to £1782.48 before you've got to your airbox, or filter.

Must admit that's the first time I've looked into how much it'd cost to buy the commercially available assemblies, comes out at quite a lot!

[Aico]

For that cash you can just as well spend a bit more and get an M3/M5 engine.

[Turbo-Brown]

Indeed, it is an awful lot of money, although we might (and hopefully will) be able to have them made for a lot less.

Be interesting to see anyway!

[Jhonno]

any pics of yours?

new is alot of £Â£, however it can be done alot cheaper with some diy and 2nd hand parts

be interesting to see your costs.., tb's work well with big cams

[Simon13]

dbilas are about the only firm i know who make throttle bodies for the M20 all in it's about £1800

but is it worth it for maybe 20bhp and loss of low down grunt?

[Jhonno]

Tb's dont necessarily lose you alot of low down torque, but they do sounds fantastic and can add alot to the top and mid range, it will drink more when pushing on, however on the m/way it'll be pretty much as standard

[Simon13]

all they do is just as u pointed out is move the power up the rev range and gain a little. Unless it's all set up properly

I thought about getting some for my sport when going 2.7. I would to the alpina but it would be moving the car away from it's original character imo

[Turbo-Brown]

There shouldn't be any reason for the power band to be shifted up as long as the inlet runners are long enough / the same as the original system, and with big cams, you should be seeing an increase in low end tractability with ITBs, plus realising more benefits from your cam higher up.

[Turbo-Brown]

Well, I've sent the final two drawings out for pricing so hopefully it won't be too long before we know exacly how much these would cost!

[Turbo-Brown]

Blimey that was quick, the final prices are in!

Well, the verdict on the prices is that they're not that bad, but still not cheap!

For the metalwork which would include 6No. 40mm choke ball-bearing throttles, 3No. port transition plates, full linkage kit, fuel rail mounting kit, fixings but which excludes an airbox and the gaskets to mount the throttles to the head:

£1302.15

I'd estimate an airbox would add about £100 onto that so an all up kit would be £1400.00

Well, if nothing else it's been an interesting exercise in design work (although I do enough of that during office hours ) Again, I invite your comments and if anyone ever actually wants a set then post here or drop me a PM

Cheers!

Alex

[chu346]

Well thanks for the effort but it would probably be better to get the dbilas kit for £1,500.

I was hoping you was going to say well under a grand

[Andy335Touring]

Would bike TB's/custom manifold be feasable ?

Or have some M20 inlet flanges made and weld them to the bike TB's ?

As you would be chopping the bike TB fanges off you could may be angle them to a slightly more favourable angle for clearance issues ?

You need some one local and freindly who can TIG weld cast aly though.

May be as a budget option you could do away with a plenum and offer to use sock filters on the trumpets ?

[Turbo-Brown]

You and me both Chu!

Will clear the decks with other projects I've got on the go and then I might have a set made up for Brown.

Twas a nice idea, but it's understandable that people don't wanna spend that much money on something which (on it's own) will probably net them about 20bhp, having said that, they would open up a world of possibilities with cams!

There's no reason bike TBs couldn't be used, as you say it's mating them to the head that's the tricky part. Think it would actually end up costing more if I didn't do the airbox believe it or not.

I designed the throttles to accept Weber (etc.) trumpets and buying them plus 6 filters would cost probably more than the £100 I'd do the air boxes for. They'd also pick up a lot of warm air I guess.

Nope, unless four or more people approach me with the readies, I think these will remain on the drawing board untill I have some made for myself

Having said that, if again 4 people wanted adaptors to mate bike TBs to the M20 head, I could adapt the design which would come out at about £370ish

[JazzMan]

This sounds very interesting. It's something thats somewhere lower down on my list of possible tuning options. Not something I want to do yet, but eventually maybe.

[chu346]

I thought that you were offering bike throttle bodies in the first place?

So, you saying £370 for the manifold but what about the other pieces that would be needed, how much would they come up to? I don't know too much about throttle body setups

[Turbo-Brown]

Nay, the kit I was offering had my own bespoke throttle design which is all CNC machined from ali. These were gonna bolt to adaptor plates which serve to translate from the 40mm bore of the throttle down to the 34mm of the port and also provide the recess for the oil breather tube.

I haven't really got a clue about bike TB prices to be honest, and I don't know what sort of mounting dims they have so I couldn't really offer an air box and people would need to tell me what diameter stubs they needed machining so they could attach them with the rubber tubes they all seem to come with.

[M5pilot]

Throttle bodies with a Carbon Airbox is what you want! Would make an flipping mad noise!

The problem with Individual throttle bodies is that you ideally need stand alone management to get the engine running to its max potential.

Simply bolting on a Dbilas kit and keeping the AFM is a bit of a waste of time.

You need something quite powerful with good resolution to be able to create a MAP that isnt crude.

Standalone itself isnt exactly cheap so the cost becomes very high.

[Turbo-Brown]

Well, we do have our Zone MegaSquirt expert who can supply, fit and tune a standalone for very reasonable money, but yes it is another expense to consider.

[JazzMan]

Engine rebuild (valve stem oil seals need doing) - maybe 2.7?, Megasquirt/Emrald, hot cam are the list before individual throttle body's One day. Gotta get the car on the road first! Engine rebuild is due for next winter is the car gets finished this year.

[E30BeemerLad]

www.boggbros.co.uk

I was quoted £700 for a turn-key conversion for the 325 onto bike carbs

[dazleeds]

www.boggbros.co.uk

I was quoted £700 for a turn-key conversion for the 325 onto bike carbs

what would this add to betty mate??

may consider some extra madness when i swap engine over

[E30BeemerLad]

i was thinking better throttle response and more top end power, if you get the lenght of the inlet trumpets sorted, then this helps to dial in the low end grunt generally.

yes it was for betty.

Junk the M20 boat anchor though. You know what i'm gonna say next though

[dazleeds]

i was thinking better throttle response and more top end power, if you get the lenght of the inlet trumpets sorted, then this helps to dial in the low end grunt generally.

yes it was for betty.

Junk the M20 boat anchor though. You know what i'm gonna say next though

trust me mate
im now a semiconvert and fully understand and appreciate that particular plan and as im craving powerrrr like never before who knows mate

[Toby_Unna]

my mate's just put some fireblade bodies on his integra-r engine. it was very easy and very cheap. cut down original manifold and welded on stubs at a nice angle and with the same spacing as the bike bodies. join bodies to manifold stubs with rubber tubing stuff. works great and cost low hundreds including buying the bodies. he does have a friendly welder to do the tig manifold work, but it didn't take many hours to get it done.

you also get a TPS already mounted, making MS easier

how about 2 sets of triumph 3-pot bodies on an m20? or benelli ones

[chu346]

Do bike throttle bodies have sealed ball bearings?

[rat]

Have a try on this mob:

http://www.deansengineering.com/contact.html

They used to make complete Lucas fuel injection systems for about £3 ex factory (a few years ago mind)

[Andreas]

Turbo-Brown, you have a nice idea, however I do not think that you are going to sell that very well.

People looking for a performance gain will probably (read 95%) think that the power gain is just too small for the amount of money spent. When you consider how many things you also have to buy to make it work well (e.g. racing cam and matching valve spring set, aluminium or titanium valve spring retainers to prevent valve float, aftermarket fuel injection, new pistons with higher compression and bigger valve reliefs for that high lift long duration cam, dry sump oil system with a higher pressure to supply oil to bearings at 8000rpm, stronger and lighter conrods, etc. etc.), then most would rather put on a turbo instead.

A person has to really be in love with the intake sound that throttle bodies can produce and buy them for that reason. I remember when I bought mine, I couldn't stop asking how loud they are going to be.

My daily driver is a E46 M3 CSL and I love nothing more than giving pedestrians and drivers with open windows a good scare. The CSL is a very quiet car below 3000rpm, so it is easy to sneak up on someone (hope you don't think I'm mean).

I bought the throttle bodies for my Alpina B3 2.7 as well as a Schrick 304 degree cam. I am going to attempt to make an intake manifold out of carbon fiber. To help the carbon fiber guy, I will machine a mold for him that we designed using CAD/CAM (the transition from round to square port is imperceptible, its amazing).

When it is finished (2 - 3 months I hope), I will let you know how much the excercise cost me.

Hope you build yours and let us know how it turned out.

[Turbo-Brown]

Yeah, they are expensive for what they give you on their own but they do open up the possibility of cams and bigger valves etc will road drivability.

Used to love the induction noise of the GT6 which just had twin CD Stromberg carbs, but I really can't hear the noise the M20 makes, despite the TBs although I guess the noise of the turbos might drown it out

[Andreas]

Yeah, they are expensive for what they give you on their own but they do open up the possibility of cams and bigger valves etc will road drivability.

Used to love the induction noise of the GT6 which just had twin CD Stromberg carbs, but I really can't hear the noise the M20 makes, despite the TBs although I guess the noise of the turbos might drown it out

I confess that I do not know what physical phenomenon causes the loud intake roar of TBs, however from my observations they are loudest when you have just the throttle bodies and a ram tube. If you add air filters, they become more quiet, if you add an airbox they lose volume again.

Now your car has such a long intake system (boost pipes and probably an intercooler) where the pulses from the engine can cancel each other out (my theory, no proof) that you wont hear anything. Add to that the spinning compressor wheel of the turbo and you have no hope of your TB sound ever coming out of a turboed engine's intake system.

[conrod]

Throttle bodies with a Carbon Airbox is what you want! Would make an flipping mad noise!

The problem with Individual throttle bodies is that you ideally need stand alone manageement to get the engine running to its max potential.

This is the setup a friend has on his M20:

http://i56.photobucket.com/albums/g196/ ... 45_IMG.jpg

It is a 2.7 fitted with a lot of goodies, including Jenvey ITB's, Schrick cam, forged pistons, Motec ECU etc. It makes 250 bhp and torque (220lbs ft from memory) all the way from 3000 to 7000 rpm. I have driven this car (a track car) and it is a HUGE improvement over the stock 2.5 previously fitted. Although as you have all guessed, none of it was exactly cheap. Probably would have been cheaper to fit an S50 engine, but it does show what can be done. And yes, with that carbon airbox it sounds awesome!

[m-dtech]

depends on the bike carb...

depends if its EFI

used to be alot of talk about bike carbs on the old a-series engine years ago but was a total cunt to set each carb up.