SR3RS Fuel Level

[Sigmamark7]

I'm new to Radicals and have an SR3RS with a dry break fuel system. Can anyone give me an idea how to find out how much fuel is in it (other than allowing it to run dry on track)?

[Zuluracerx]

Don't let it run dry, they tell me that's not good for the engine. There must be a way to verify fuel but if there is, I'm still searching. What I do now is fill it up to the max and then run a specific number of laps on my local track (2.5miles) and then refill to get a pretty good idea of fuel consumption. It sucks this way, but it's the only way I have figured out how to get close. When I'm at other tracks I have to do some math to keep from running dry, or put into quali trim. Surely, there must be a better way?

[Steve57]

drain it out is the only way to know for sure.

[double d racing]

a combination of both...
1. drain completely
2. allow 0.75l per lap ( most circuits )
3. stick in 10l or 20l depending on your expected session
4. calculate/accurate record of number of laps
5. assess driving - ie flat out for 10 laps, ambling, slow traffic, mixture, weather, etc
6. Drain and calculate
7 If you want to be technical ensure the car is in the same standing position as when you originally drained it.
8. Buy yourself a simple countdown kitchen timer to stick on dashboard. We set ours for about 20 mins which is the same as a race. That gives you a further guide as to how long you've been out.
In racing we are very critical as to fuel levels and have the benefit of the printed data from race control - exact laps etc.
Track days we simply put in 20l and after every session add about 10litres taking into account all the scientific stuff above. At lunch we then drain and start again.

[double d racing]

I'm also making the assumption that you have the drybreak fuel line and wiring to pump the stuff out ?

[Simon T]

double d racing said:

2. allow 0.75l per lap ( most circuits )

Really? have you checked to see your getting full throttle?

[Josh Smith]

We use about 0.9 per lap

[double d racing]

aaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhh that's where i've been going wrong.....

[BertBert]

er, without wishing to cast aspersions, I am not convinced that "the lap" is a very standard unit. You certainly won't find a standard one in Paris next to the kg.

So perhaps it's not that useful a measure. Would "a minute" be better?

To the OP, throw in a litre for every minute you want to be out for. If you end up with a full tank, stop putting fuel in.
Bert

[Sigmamark7]

Thanks Guys - all very helpful stuff to me as a new boy. Based on the information supplied, I will probably now do most of my trackdays at the Nurburgring or Spa, because at 0.9 ltrs/lap, it will be much better value than Mallory Park or Llandow!
Since I am not chasing tenths (yet), I guess the answer is to brim it in the morning and fill it again after a couple of sessions to see how much it has used.
With the dry break system, will it just stop taking any more fuel when the tank is full, or will it just send any surplus back via the female vent into the churn?

[BertBert]

Definitely go for the bigger circuits, great vfm.

It may well be fine, but I don't think that brimming it is a that great an idea. Just feels wrong.

I'd actually start low and put enough in for a session. If you can get in the habit of pumping out for a known baseline it's much better.

BErt