twin carby vs efi on a twin cam motor?

Zedster · tinkerer Joined: 19 Oct 2003 Posts: 50

So can somebody tell me if the std dohc efi setup is shyte for a performance motor? Would carbies be better or would the webber style twin throttle bodies be better? I have a wolf 2d comp on an 1800 dohc at the moment. I feel it can go harder. Mind you it revs to 9000rpm already, but lacks the punch of twin carbies. Info anyone?

Stock TE · backyard mechanic Joined: 12 Mar 2002 Posts: 853

This guy http://plaza25.mbn.or.jp/~Nob_Tuji/ got about 165hp in race trim with twin 45's (I think).

Stock TE · backyard mechanic Joined: 12 Mar 2002 Posts: 853

That was made at 6500rpm with redline at 7900rpm.

GEMTEC · tinkerer Joined: 02 Aug 2003 Posts: 216

damn it! i knew i shoud have paid attention in school in the japanese class Sad

Stock TE · backyard mechanic Joined: 12 Mar 2002 Posts: 853

http://world.altavista.com/ Use this, its still a bit hard to understand though.

GEMTEC · tinkerer Joined: 02 Aug 2003 Posts: 216

carbys are crap! carbys are crap! carbys are crap! carbys are crap! carbys are crap! carbys are crap! carbys are crap! so therefore, i willing to buy them off you. im thinking that since im sucha nice guy, ill just take them off ya hands eh? i really need a pair Wink

PS. jokes mate, carbies are real good on power, but fuel economy is a different story. am i right guys or what?

GEMTEC · tinkerer Joined: 02 Aug 2003 Posts: 216

oh yeah. works a treat. thanks mate

Loz · backyard mechanic Joined: 05 Oct 2001 Posts: 943

Carbies are alright but never match injectors for accuracy and power. Carbies can lean out to easily on 1 cylinder where as efi will shoot fuel straight into each pot.
The only reason people stick with carbies is simplicity and cost.

QldRobbo · tinkerer Joined: 11 Apr 2002 Posts: 455

EFI is a lot better than carbies for both economy and power, if you feel that your EFI isn't going as hard as it should though, fit a bigger throttle body and port your manifold and get it retuned.

gem · tinkerer Joined: 23 Dec 2001 Posts: 152

If you intend on using the stock efi manifold forget it. You will not get enough air past the throttle body.I have a 2.0lt twin cam which made 120hp atw with stock manifold and Haltech. I used my quad 45mm throttle bodies and Autronic smc and the engine made 140hp atw. Twin 45mm webbers will make the same top end power as efi but with less drivability. I think 9000 rpm is a bit high! Are you sure your tacho is correct? MY race engine with forged pistons nitried crank and lots of other work is set to 8500rpm and the engine is rebuilt after 6 race meeting.The bearings are totally stuffed with these sort of revs. I have a twin webber manifold but I want to sell it with an engine.

Loz · backyard mechanic Joined: 05 Oct 2001 Posts: 943

You will if you force it Wink

DOHC_TF · tinkerer Joined: 11 Feb 2003 Posts: 123

Hey Gem do you have any pics of your throttle body/manifold and how much did the throttle body cost, wat was it off??

If u hav any pics could u plz send em too monaro_man327@hotmail

cheers