Innovate AFR Test
Discussion
With the greatest of, my dear Rusti, I'm resigned to give the carb one last chance.
Three things hold me to this thinking:
1) The state of the cam lends it's self a carb rather than the sensible EFI (don't ask me why, but I've heard)
2) The car is getting pretty trick for track so I'm not too bothered about my tab at the local station. After all day to day running is what a Toyota is for
3) It's factory std gear. I can enjoy my pineapple and cheese on stick, smug in the knowledge that it's what Ted would do....(brown nose Lucky)
So if you don't mind, lets keep this one on carb performance. Not carb V EFI he-he!!!
Three things hold me to this thinking:
1) The state of the cam lends it's self a carb rather than the sensible EFI (don't ask me why, but I've heard)
2) The car is getting pretty trick for track so I'm not too bothered about my tab at the local station. After all day to day running is what a Toyota is for
3) It's factory std gear. I can enjoy my pineapple and cheese on stick, smug in the knowledge that it's what Ted would do....(brown nose Lucky)
So if you don't mind, lets keep this one on carb performance. Not carb V EFI
he-he!!!Good for you Pete....... heads, cams and carbs for me too (However, I do fancy the idea of a 377 screamer with one of Dave's pro-chargers on it--- having changed initial spec once already, it'll have to be the next motor).
Anyhow I know you have a very good man on your engine, setup etc but if you do come unstuck it might be worth having a quick word with these guys, http://www.prosys12.macwebsitebuilder.com/blaster1... having spoken to them they are very switched-on with 'circuit race' carb building for the american V8 market. Good luck.
Anyhow I know you have a very good man on your engine, setup etc but if you do come unstuck it might be worth having a quick word with these guys, http://www.prosys12.macwebsitebuilder.com/blaster1... having spoken to them they are very switched-on with 'circuit race' carb building for the american V8 market. Good luck.
CanAm Dave said:
bluesatin said:
Once set up carbs work OK. My concern with aftermarket efi is if the lambda misreads it can kill the engine!
Please explain your thoughts here! As mine could not kill the engine.Regards Dave
Plenty of efi setups dont run a lambda sensor at all !!!!...maybe they are dead
And on the other hand.....millions, if not billions of efi setups run lambda sensors.....have done since 1992 in virtually every car built.
Edited by stevieturbo on Saturday 2nd August 17:44
bluesatin said:
The modern LS engines built with EFI are the way to go but an sbc with an efi kit concerns me. God know how many sensors my porker has but not quite the same as some of the efi kits I have seen and this concerns me. Saying that I am going megasquirt for ignition only!
Why on earth would it concern you ????Fitting efi to a car isnt rocket science, and OE cars, have more sensors than are absolutely necessary at times.
Enquired with Holley as to the state of tune of my carb. Sent them the video clip and asked what they thought I could do to lower the crusing AFR but maintain the acceleration and WOT rich mixture. This was their response:
'What ever the engine wants is what you need to give the engine. Wide band is good tool for WOT but a carburetor can not be tuned like a fuel injection system. Best mileage will be defined by how the engine runs best. lean mixture will cause the throttle to used more and engine will have to work harder.'
Anyone care to explain?
'What ever the engine wants is what you need to give the engine. Wide band is good tool for WOT but a carburetor can not be tuned like a fuel injection system. Best mileage will be defined by how the engine runs best. lean mixture will cause the throttle to used more and engine will have to work harder.'
Anyone care to explain?
I'll take a stab but only based on EFI logic .. the weaker you run the mix (from optimum) the more the hp drops off, so to claw your hp back so as not to lose speed you must open the throttle a bit more .. now that at first seems counter intuitive because if you're opening the throttle you must be using more fuel yes? Well no, because as you open the throtle the dynamic cylinder pressure (the pressure actually in the cylinder during compression) is higher because you have strangled the intake less by opening the throttle, this makes the engine more efficient .. therefore your weaker mix on a more open throttle is actually more efficient than a richer mix on a more closed throttle even though the hp production is exactly the same. Same hp but less fuel used. You can only take advantage of this if you have the ability to fine tune the mix and ignition at each load site, something carbs and distributors are piss poor at.
Ditch the carb .. unless you're running in an historic race or concours series there is no good reason why you should keep it
Ditch the carb .. unless you're running in an historic race or concours series there is no good reason why you should keep it
LuckyP said:
My fault for posting the equivalent to 'what's the meaning of life?' so late in the evening.
Gail (A/S) has just seen this and replied to me. The cam I am running (the 720 factory cam) has moosiff overlap, and it is very difficult to get it to run to 14 on cruise.
I spec'd trackday tool and I that's what I got!! Can't wait to get it on the tarmac!!
I'd be wary of potential bore wash for daily driving then Pete. I believe that both Bluesatin and Crazyofcookham have had problems in caused by this.Gail (A/S) has just seen this and replied to me. The cam I am running (the 720 factory cam) has moosiff overlap, and it is very difficult to get it to run to 14 on cruise.
I spec'd trackday tool and I that's what I got!! Can't wait to get it on the tarmac!!
Still, it keeps Charles Dunnin business
Gassing Station | Ultima | Top of Page | What's New | My Stuff