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MR_GEMI hod rodder
Joined: 05 Oct 2001 Posts: 7826 Location: Adelaide
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Posted: Tue Jul 02, 2002 3:30 pm Post subject: EFI IN A GEMI |
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Ok befor you all yell at me, i have done a search and read the workshop article...
but im left with a question... in the workshop article, it says that "Firstly I want to dispel a few myths about EFI on the humble Gemini: If you are expecting neck breaking power gains from it, read no further and go and buy a big bore engine and some twin-carbs"
well i went out an bought a big bore engine but cant get a hold of twin carbs, and i am thinking EFI may be the way to go... now to the question: will there be much of a power gain considering i have the big bore etc???
any help greatly appreciated!
cheers,
kev _________________
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Pete backyard mechanic
Joined: 05 Oct 2001 Posts: 502
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Posted: Tue Jul 02, 2002 3:49 pm Post subject: Re: EFI IN A GEMI |
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well, i think... couldnt you tune the efi to pump in heaps of fuel therefore simulating twin carbs? |
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Soop backyard mechanic
Joined: 30 May 2002 Posts: 748
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Posted: Tue Jul 02, 2002 4:42 pm Post subject: Re: EFI IN A GEMI |
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Doesn't EFI just give you smoother acceleration with less flat spots?
I have efi in my car and it accelerates really smoothly, at certain revs the engine winds up a lot and puts out a lot of power really suddenly. Feels awesome, a bit like a turbo spooling up.
Accelerates much differently than a carb setup for sure. The only thing close to it I've driven was a worked 1600 with a sidedraught, it was good but not as responsive (still good though). |
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MR_GEMI hod rodder
Joined: 05 Oct 2001 Posts: 7826 Location: Adelaide
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Posted: Tue Jul 02, 2002 5:01 pm Post subject: Re: EFI IN A GEMI |
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well would you say it is worth wile in a hot 1600?? _________________
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Phil tinkerer
Joined: 05 Oct 2001 Posts: 170 Location: Brisbane/Sunshine coast
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Posted: Tue Jul 02, 2002 5:36 pm Post subject: Re: EFI IN A GEMI |
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Think of it this way...
EFI provides a much more accurate fuel metering system than cabies can. So EFI will provide smoother acceleration over the entire rev range(as long as its tuned correctly) and better fuel economy because its providing the right amount of fuel all the time. For the sake of simplicity, I'll say you won't gain power by just changing to EFI. Where you gain power is in airflow. Just adding more fuel won't give more power(generally speaking). You need to get more air in, so you can add fuel to it and therefore get more of the same air/fuel mixture into your engine, easier. So specifically, you could say that for a given engine, it depends on the type of inlet manifold you are using. A less restrictive/bigger one will GENERALLY allow your engine to make more power regardless of the type of fuel delivery as long as the fuel delivery system is providing the right amount of fuel(ie. is tuned properly)
phew |
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Soop backyard mechanic
Joined: 30 May 2002 Posts: 748
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Posted: Tue Jul 02, 2002 6:43 pm Post subject: Re: EFI IN A GEMI |
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I dunno, mines a 2ltr twin cam.
Worth it if you want it/wanna pay for it I guess |
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Ben Wight backyard mechanic
Joined: 04 Oct 2001 Posts: 946
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Posted: Wed Jul 03, 2002 12:52 am Post subject: Re: EFI IN A GEMI |
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The comment about getting twin carbs if you want more power was made because similar power will be obtained from both a good efi setup, or twin carbs, but of the two, twin carbs is typically cheaper.
If anything, you should be able to get more peak power from a twin sidedraught carb setup than from your average rodeo injection manifold, due to the sidedraughts ability to flow more air. I would say typically though, the efi setup would have a flatter torque curve as the ideal a/f ratio for max power is held constant over the entire rpm range when properly tuned. Carb tuning is very difficult to get right with respect to the right mixtures over the entire rpm range.
You can do it with many many hours of dyno time, but it can be done a lot more quickly with an efi setup and programmable management.
Therefore, if you already have 'the big bore', then either way will make good power. Efi will generally cost more though. As far as power gain, if you are using the nikki and standard inlet manifold, then you will get a decent power gain, assuming you have good a good flowing head, good cam, good exhaust, etc.
Ben Wight |
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MR_GEMI hod rodder
Joined: 05 Oct 2001 Posts: 7826 Location: Adelaide
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Posted: Wed Jul 03, 2002 2:20 pm Post subject: Re: EFI IN A GEMI |
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WOW! cheers for the responses they have been great and have answered all my questions!
ive pretty much made up my mind... i will go with the EFI!!
thanx again!
kev _________________
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