Ok guys...here's one for you!

My car is an '88 GTA with the engine out of an '86 'vette - so ally heads, different cam etc. I've just put a set of platinum plugs and 8mm Accel wires on.

Here in the UK, we have 95, 97 and 98 RON petrol. I'm now tending to run 97 or 98 in the GTA.

My timing is set at 6 degrees BTDC. It seems to run better if I retard it more - even towards 10 or more.

Can anyone suggest a reasonable setting given that I'm running 97 RON??

Thanks!

 

Start with the factory setting, and find out what grade fuel it should be running on (what GM reccomends). And go from there.

 

If its pinging you have to back of the timing or buy higher octane fuel.

I'd set the timing to factory and buy the recommended fuel which is going to be a higher octane.

I would try to save money on something else besides gas.

If you back of the timing and use a lower octane, pay attention to how you drive and make sure you are getting good miles per gallon. Setting it to factory settings with the recommended gas may actually be cheaper becaues of your mileage. You'll have to keep backing off the timing until it quits pinging.

Especially in the long run. A friend of mine used to put cheap gas in is 89 Z. I just cringed when pressed the gas. Pinging is like finger nails on a chalk board.

I have a 4 banger to save money on fuel. My V8 only exercises on weekends.

I'm curious what are the prices for the different octane ratings?

 

Thanks guys - but neither of you read the post!

The car is designed to run on cheap 87RON fuel.

Here in the UK it is 95/97/98.

This means I should be able to run between 8-10 degrees BTDC but wondered if anyone has any experience of this?

Thanks,

 

As for prices...

95 RON is about 96.9p - that would be $1.72 per UK litre... or $6.50 a gallon

97/98 RON here is about 99.9p - that would be $1.78 per litre or $6.75

I'm tending to run the 97/98 RON now as the Shell and BP we have here come with performance enhancers.

What's the current RON rating in the US???