DIY Throttle bodies

vocky

I'm thinking about doing my own throttle bodies conversion notsure.gif

not sure whether it will happen but thought members could post any info in this thread.

Use an Emerald ecu, like this
http://cgi.ebay.co.uk/Emerald-K3-engine-management-ECU_W0QQitemZ300091604239QQihZ020QQcategoryZ72205QQrdZ1QQssPageNameZWD1VQQcmdZViewItem

Make my own inlet manifold and use some secondhand throttle bodies dunno..

Use two injectors per cylinder, retain the original and add another pointing directly into the throttle opening on each cylinder and have this injector switched to work on full throttle position.

comments and ideas welcome cheers..

Sjdickso

Hope you can pull it off, i would not have the first idea where to start! Will thorney ever realise a date for there TB conversion? I am sure you can do it though.

alanoo

Yep, not as hard as we think... just have to use a custom made manifold because none exist. (do not forget the vaccum for the brakes)

Use an emerald or another programmable ECU, stick a trigger wheel + sensor on stock pulley, the hardest part should only be to fit a throttle cable and here you go.

vocky

TMS still haven't set a release date for their kit notsure.gif

cost seems to be quite high too 🙁

for my vx220 the throttle cable will be the lotus system 🙂

a vectra or astra could simply use a cable system from another engined model 🙂

alanoo

Yep i've not seen exactly how the lotus systems works
Do you have to change the whole pedal box or only the throtlle one ?

Plus my main problem is that it is easy for you to find a RHD throttle from an Elise, but an LHD one for me... should be a little bit more difficult 😉

vocky

I've not looked into the lotus pedal system, but hopefully it will just be the throttle pedal requires changing dunno..

alanoo

Yep don't know how it works, i tried to find a pic some weeks ago without success

Steve_Crisp

I've driven (briefly) Thorney's throttle-body car, and the one slightly negative thing was I dodn't like the feel of the cable throttle. John said that he was changing this to something else so I've no wish to judge the wrong thing, but it did get me thinking that I really want to retain the electronic throttle.

Has anyone looked at removing the electronic throttle control from the standard throttle-body and adapting it onto another TB?

I've got a spare TB in the garage, so perhaps I'll take a look tonight after my walk!

Steve

vocky

what was your overall impression of the modification notsure.gif

nice and smooth power range or lumpy and brutal dunno..

my own experience has been fitting twin 45 webbers to a few cars, which I loved 😃

I expect mine [with throttle bodies] to be a similar performance as the TMS conversion power dunno..

Mine will have a 7000 rev limit (I want my engine to last) and with no balancer shafts plus a 4-2-1 manifold it should equal out dunno..

Steve_Crisp

Certainly not brutal - in fact very driveable at low revs - it could have been a standard NA until I reached 3000+ and then everything kicked in.

Unfortunately he lent me the keys when everyone was knocking-off work so I joined a traffic-jam on the dual-carriageway! I had one chance to get it moving in second and third, and it sure felt (and sounded) good when things started to happen. So not a good test, but enough to be happy that it was the way for me to go.

Steve

Steve_Crisp

Is there any interest if I were to develop a fly-by-wire drive module for after-market throttle-bodies?

No promises, but I have a spare TB that I can strip-down and investigate how to create our own. The main issue (if the interest is there) is keeping it as reliable (if not more so) as the original AND keeping the price low...

PS I'm looking forward to finishing my first 20 posts so's I can then see what some of you guys are selling in that section.

Steve

vocky

the main road outside tms is a bottle neck at peak times :roll:

I live only a few miles from tms so avoid that area at that time of day :lol:

the main problem with having an electronic throttle body is whether the aftermarket ecu can control it, but saying that a piggyback ecu could be used instead dunno..

it should be quite easy to do notsure.gif

the way the throttle body works is:

a 12v motor and two pots - one potentiometer opens and the other closes

Steve_Crisp

Ah, I would love a non-Vauxhall ECU to play with - anyway we don't need an ECU to control the electronic throttle, a PIC-chip will do a good job maybe.

I like the idea of being able to also programme the response curve of the throttle to my taste. It can be made linear or logarythmic or any shades in-between. It sounds like a wheatstone-bridge type arrangement so a few components should work.

Steve

vocky

you could always buy a megasquirt ecu in kit form and build it yourself 🙂

http://www.glensgarage.com/catalog/megasquirt-kits-c-1.html

Robin

Vocky, what's the resoning behind the twin injector setup? 4 larger injectors would be easier and with a decent map, fuel economy at lower revs would be unaffected :?

vocky

the emerald has the function to run eight injectors, seems a waste not to use it 🙂

basically the standard injectors would be used below 3500 rpm [for good fuel economy] after that the second (bigger) injectors will gradually fade in and then take over, this gives maximum power potential showo..

also with the injectors pointing directly into the throttle opening there will be a better fuelling mixture entering the engine too 🙂

it's all explained in the Haynes Engine Management book

I would have gone the four injector route before reading that book :roll:

Robin

I see.

Just wondered really as a friend of mine was planning an 8 injector setup for his 230bhp+ 1.6XE but after a lot of deliberation, decided not to bother as it just complicates things with the map and doesn't show much of a gain over 4 bigger ones.

His is a track car though, not a daily, so fuel economy isn't as much of an issue for him :lol:

vocky

that's the main difference, fuel economy is usually better with eight injectors 🙂

vocky

just found this company, the tb's look superb drool.gif

price is good too, about £600 inc vat for a set 🙂

http://pulse-racing.co.uk/pricethrottle.html

markv

I've been following the whole Webcon individual throttebody story closely. I have to say that I am really beginnen to doubt if that route makes a lot of sense if (such as in my case) you don't want to raise the revlimit too high.

From what I've seen when people start tuning Elise's, they usually start out to put in different cams after optimizing the exhuast. AFAIK the normal way to tune an NA engine. But with a plenum setup you are going to run into trouble when you put in cams that become too agressive. With the longer valve openings, you get pulses going from one cylinder to the other on the inlet side, because all intakes come together in one room. That usually leads to problems running the engine on idle.

You can solve this by using variable valve timing systems (simple, or the VTEC like systems which are more extreme). Or you can put in 1 throttle body per cylinder, preventing the pulses to interfere with other cylinders.

So basically, you need wild cams, then you should get the real benefit of the throtllebodies. So with the conversion to throttle bodies on the otherwise standard engine, the throttlebodies are a bit overkill.

Still, you see an improvement. The engine delivers peak power at higher RPM. The only two changes are the ECU and the inlet. Assuming the standard ECU isn't the issue when correctly remapped, that means the inlet is a problem on the standard engine. That would explain why the z22se doesn't seem to make max power at very high rpm. Usually (I see this with my engine too) max power is way below 6000rpm. Even with 245 degree cams, that is very low.

Results from other people that have tuned the engine seem to confirm this. As soon as the intake manifold is changed (usually with a dbilas) you see the top power RPM go up. Foung these guys on the web:

http://www.lotusspecials.com/index_speed.html

Their "stufe 6" specifies 195-200bhp on the standard ECU without throttlebodies. Doesn't sound too strange, even Webcon lists those kinds of figures for the ford 2.0 duratec engines. See:

http://www.webcon.co.uk/alpha/AlphaPlusKits.htm

220bhp with O/E throttle body.

So with my goal of not running high rpm (not over 7000), will the throttlebody route be really usefull? I'm not convinced yet..

Mark