Alphabettispaghetti
Club Member
I wonder how many of those people with issues have had their car on a rolling road and gone through a full proper setup?
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Carb Flooding
- Thread starter Rob Gaskin
- Start date
Yes and do the people 'tuning' have all the knowledge/jets etc.
Anyway I will - already discussed it.
racer
Club Member
uk66fastback
Club Member
What do people consider 'bad fuel consumption' on these cars?
Alphabettispaghetti
Club Member
I think that's more than half the trick, finding some where that are knowledgable and comftable in setting them up.
Mr Ex Jnr
Club Member
'I've seen with triples seem to have issues - not least horrendous fuel consumption. My car (apart from when it flooded!) is good on fuel and my old track car was too.
I just feel I need to join the triple brigade to see if a performance advantage can be gained on my DJR modified engine, the previous owner was against triples.'
Iv only ever been in a zed with webbers on
I'd like to experience a few other zeds ie like standard zed with su never been in
Now mine running bit on the rich side but I got to oulton park and my hotel then back to the track then home on 50 pound worth petrol dunno what other people are like but I don't drive it every week so I class it as a treat
I just feel I need to join the triple brigade to see if a performance advantage can be gained on my DJR modified engine, the previous owner was against triples.'
Iv only ever been in a zed with webbers on
I'd like to experience a few other zeds ie like standard zed with su never been in
Now mine running bit on the rich side but I got to oulton park and my hotel then back to the track then home on 50 pound worth petrol dunno what other people are like but I don't drive it every week so I class it as a treat
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I've heard of 20 mpg.
All 3 of my Zeds have done very high twenties and come to think of it so did my 370Z.
I would hope to get 25 out of mine with triples - we will see.
That's unacceptable to me. It shouldn't take that much fuel to move a 240Z.
That needs tuning Christian.
I think you can get a pair of HS6 carbs from Burlen. They always say stuff is out of stock because they manufacture to order. Having said that, there will be a lot of fettling to do on the HS6 as the throttle linkage is different and I am not sure they bolt straight onto a nissan balance tube.
The best bet is to go to Z Therapy in the States. They do the proper job and are not too expensive (at least until the shipping costs are added)
Ali (Smileyinside) has used ZTherapy so he may be able to give some perspective.
Yup as Mr Farmer said the ZTherapy carbs are as good as new; if not better given their sealed throttle shaft bearings and SM needles. They totally transformed my car and at c.£500 worth every penny if you are not chasing high displacement, big BHP and 8K RPM.
The SM needles do run a little rich on a stock engine but half the fun is fiddling to get them set up right (which is easy). I had the benefit of the very interested MOT guy with rollers and an oxygen sensor helping me. So it was even easier!
johnymd
Club Member
The engine old on my blue car was a 2.8 with "nice" head and triple 40's. It went really well and delivered low to mid 30's to the gallon on our trip to Le Mans in 2010. We were taking things easy though and rarely went over 80mph. The car was re-jetted on a rolling road just before we went and a lot of time was spent getting it as close as possible to correct. Carbs are never perfect but if you can get in the ball park then fuel consumption shouldn't be that bad. Aim for 14:1 AFR on cruising and there's no reason why you should use loads of fuel. Cruising and transition fuelling is something most rolling roads really don't want to do as its so time consuming but that were the economy is found.
Correct Stoichiometric ratio is around 14.7:1 for complete combustion.......irrespective of induction choice....carbs, FI or aunt Daisy's turkey basting spoon
This ratio will be tweaked around driving conditions (acceleration or idling) but generally its a golden number
In short, to make X amount of power, Y amount of air and Z amount of fuel is required in that ratios.....independent to the induction choice and /or aunt daisy's cutlery
If the car is only getting 13 miles / gallon then outside of the lead foot effect, one or more of the following are happening
1. The larger carbs (higher air/fuel flow potential) are unleashing huge amounts of additional power
2. They are running rich ...
3. Fuel is leaking the entire length of the A5.....
Maybe thats why people fit those crude fuel catching trays over the exhaust.
This ratio will be tweaked around driving conditions (acceleration or idling) but generally its a golden number
In short, to make X amount of power, Y amount of air and Z amount of fuel is required in that ratios.....independent to the induction choice and /or aunt daisy's cutlery
If the car is only getting 13 miles / gallon then outside of the lead foot effect, one or more of the following are happening
1. The larger carbs (higher air/fuel flow potential) are unleashing huge amounts of additional power
2. They are running rich ...
3. Fuel is leaking the entire length of the A5.....
Maybe thats why people fit those crude fuel catching trays over the exhaust.
Alphabettispaghetti
Club Member
Correct Stoichiometric ratio is around 14.7:1 for complete combustion.......irrespective of induction choice....carbs, FI or aunt Daisy's turkey basting spoon
This ratio will be tweaked around driving conditions (acceleration or idling) but generally its a golden number
In short, to make X amount of power, Y amount of air and Z amount of fuel is required in that ratios.....independent to the induction choice and /or aunt daisy's cutlery
If the car is only getting 13 miles / gallon then outside of the lead foot effect, one or more of the following are happening
1. The larger carbs (higher air/fuel flow potential) are unleashing huge amounts of additional power
2. They are running rich ...
3. Fuel is leaking the entire length of the A5.....
Maybe thats why people fit those crude fuel catching trays over the exhaust.
I did follow a guy in a 240z a few weeks ago, his car was running that rich that i could smell fuel in my car at 60mph.
How did you find the transition from carbs to FI? For ultimate performance I agree FI yealds easier to get results etc.
Mr Ex Jnr
Club Member
I doesn't **** out seeps a little bit av only noticed that recently after getting to oulton it's always run rich but never seeped.
Wat am saying tho is I don't run it with air filter just trumpets so air be going in quicker would that make it use more fuel.
Wud it use less if I had air filters on
Wat am saying tho is I don't run it with air filter just trumpets so air be going in quicker would that make it use more fuel.
Wud it use less if I had air filters on