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General => The garage => Topic started by: benji mk2 on 23 March 2005, 08:55

Title: twin carbs or throttle bodies mk1 1.8 8v
Post by: benji mk2 on 23 March 2005, 08:55
So guess which smart arse just got him self a fancy new job?? Found out on Thursday and gonna be getting lots more cash  :grin: :grin: :grin:
As a result Ive decided to spend all my new found wealth on my baby!!  The engine work has begun: Full lighten and balance, bored out to 2ltr lots of head work and a sports R Kent camshaft. By big problem now is do i fit twin 40's, 45's or throttle bodies? My understanding is that throttle bodies although more expensive will be much more manageable. Does anyone have any thoughts/experience with either of these systems.

Cheers,

 Ben
Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: sportline_velly on 23 March 2005, 09:15
carbs are easier to fit and you will get great power and torque but very very low mpg!
i had twin 40's on my 16v , 170 bhp but only 20 mpg  :embarassed:

TB's are better but cost £Â£Ã‚£Ã‚£ a few people are looking at using bike TB's much cheaper but u need to make it all up yourself

2.0 is the way to go IMO..esp if  you go 16v too :evil:
Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: davidhawkins_78 on 23 March 2005, 10:29
My understanding of throttle bodies is they are just that ... carb's control the flow of fuel and air but you'll still need some sort of injection / fuel system if u use throttle bodies.

No matter what us use the fuel consumption will increase funk loads as you'll be trying to force more air and fuel in - so for cost and support of your installation I'd say go twin 40 / 45's - more people will be able to set them up and the costs will be alot less, plus the power difference between the two at full throttle will be nominal

Hope this helps !
Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: Gambit on 23 March 2005, 10:43
itd be cheaper to source a 2.0 block than bore out your existing one
Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: benji mk2 on 23 March 2005, 11:32
Cheers for all the input troops, still talking to suppliers and stuff.
With reference to the block its costing me sod all to have it bored so I'm not to fussed about it!  I've managed to find a really cheap but helpful engine re builder!
 If i was to fit the carbs what do i need to do with the injectors?
Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: davidhawkins_78 on 23 March 2005, 12:01
Stick 'em in the bin and enjoy the glorious noise of Twin 45's singing !

The fuel is controlled by the carbs as I said, so you'll need to get the fuel line rigged up to the carbs. Has anyone mention to you what else you need for that setup ??

Things like a Facet Fuel Pump - Fuel Regulator - Throttle Linkage - Trumpets etc ??

I did this all to my previous car so feel free to ask any questions !

Dave.
Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: mix on 23 March 2005, 12:34
Twin 45's, Twin 45's, Twin 45's, Twin 45's, Twin 45's,

Need i say more???
Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: Chris Green on 23 March 2005, 13:09
Carbs would be easier, but I would very much prefer throttle bodies. (I haven't built a system myself yet, but I will be at some point for me XE engine).

I have studied the "Practicle Performance Car" article on TB's, and have read loads of stuff about megasquirt, and such like.

I would assess the costs of TB's and a management such as Megasquirt 'n' EDIS for instance, and decide for yourself. No doubt TB's will be more managable, and a lot more efficient (apparently).

Some links to help you decide (All TB Based)...


http://www.megasquirt.co.uk/

http://picasso.org/mjlj/index.jsp

http://www.msefi.com/

http://www.jenvey.co.uk/

http://www.emeraldm3d.com/em_pricing.html
Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: benji mk2 on 23 March 2005, 13:15
Yeah I'm thinking the carbs may be the best way to go, i really like the idea of throttle bodies and the fact that they need very little attention once up and running (and no dizzy). But the bug@ers ain't exactly cheap, however they do give better mpg. Just spoke to very helpful guy at badger five but i'll be looking at well over 2K! Cheers for the addresses chris i'll have a look now.

David, how did you get on with the carbs?? How much hassle and how often did they need tweaking? I've got a pretty good idea of every thing i would need. Where did you get yours from?

Been told that dhla will be better in town than dcoe, any thoughts anyone?

TA
Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: Gambit on 23 March 2005, 13:38
are you get the new pistons for your rebored block free also?
Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: Chris Green on 23 March 2005, 13:40
just a thought, wouldn't it be better to go 16v now, and then save up for the carbs / throttle bodies after?
Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: benji mk2 on 23 March 2005, 13:49
Chris, still unsure on the whole 8v vs 16v debate, cant decide to be honest.

 Gambit, i see what you mean but I'm happier with paying for new pistons. I want the piece of mind that verything on the car is going to be spot on. I'm planning on using the car a lot and driving it pretty hard. The engine re builder has also already bought the pistons in  :sad:. It's all good fun!!!  Just spoke to demon tweeks and they do a pretty good price on an omex controlled TB kits, also helps that they're only down the road from me. decisions decisions.................
Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: Chris Green on 23 March 2005, 15:22
If you can afford it, get throttle bodies. definitely.

Plus, you can set it up yourself on a laptop, which would save the cost of a RR trip every few months.

Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: davidhawkins_78 on 23 March 2005, 16:02
I got on fine with mine - but then again I have a degree in auto engineering!

As for this ideal that they require constant attention it's nowhere near as bad as some make out - providing you get the correct barrel size and jetting for your engine and cam the only other tweeks will be to the idle and the carb balance which is easy anyway - and I did that monthly but didn't need it - maybe every 6 months ??

Has anyone shown you the Weber Alpha Performance kits u can get for twin webers - might be what your after ...

I'd stick to DCOE's as DHLA's are harder to service and get parts for these days
Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: benji mk2 on 24 March 2005, 08:50
Ive heard a little about the weber alpha kit, is it some sort of ecu controlled twin carb setup?
After having a night to think about it, i think the best way to go is carbs, unless i can find a reasonably price TB kit.

 Cheers for all the help every one  :wink:
Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: sportline_velly on 24 March 2005, 10:39
steer clear of the Weber Alpha Performance kits, there is only 2 or 3 people in the uk who can tune them!!!

if you want to map TB's yourself, DTA management comes with a 2.0 16v TB map in the system  :wink:

but i feel a mk1 with 2.0 16v on 45's carbs would be fun  :smiley:

you cant beat the noise  :evil:

this is my cab running on twin 40's (16v) http://www.whosurhost.com/upload/user_uploads/velly_cabs.MPG
a bad result at the wheels due to the tracking being miles out but it was 170@ fly  :evil: :grin:
Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: benji mk2 on 24 March 2005, 15:38
Hi

Cool video velly!!

Just handed in my notice at my place of work, expecting to work a full month. But as I'm going to the competition they want me to leave today! Suits me as i get a month off, ha ha ha. Anywho I've got to give my laptop back so i wont be on line for a while, don't do anything i wouldn't while I'm away. Have fun kids 


ben
Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: sportline_velly on 24 March 2005, 15:59
see u soon clart
Title: Re: twin carbs or throttle bodies mk1 1.8 8v
Post by: benji mk2 on 24 March 2005, 16:02
you knows it!!!!