[Mark Simiele]

My 69 GTO has a basically stock 400 that was rebuilt to run on todays pump gas. Despite being tuned to all stock specs and correct timing it still pings a bit on hard acceleration even with 93 octane, forget 92 as that makes it even worse.

I was curious about the effects of adding some octane booster. Some have suggested a few gallons of Sunoco racing fuel. Would either be a bad thing? Regarding the octane booster, what is a good brand to buy?

[wytnyt]

pinging is a plague with these type engines,,easiest fix is to back the timing off a couple degrees but i know that extra uumphh is hard to throw away.
did you put in valve seats so you can use unleaded fuel?
if not then you need to cure the pinging problem.octane booster comes in many ways and ive found its just try and see what works best for you
i never used it as its just too expensive to be able to keep that little extra timing .
guess im a tightwad

[Speargun]

Check these out...

http://forums.maxperformanceinc.com/...d.php?t=563372
http://forums.maxperformanceinc.com/...d.php?t=390495

[67GTONUT]

I use this

http://www.batterystuff.com/fuel-treatments/OS2q.html

[Mark Simiele]

Thanks guys, and yes, I do have the hardend valve seats to run on the pump gas. I might try a couple gallons of the Sunoco mixed with a regular fill up of Ultra as well as some of the better octane boosters you all mentioned.

[johnsma22]

Originally Posted by Mark Simiele

My 69 GTO has a basically stock 400 that was rebuilt to run on todays pump gas.

When you say that it was rebuilt to run on today's pump gas, what do you mean exactly? Was it just that the valve seats were replaced with hardened ones for use with unleaded gas? Or was the compression ratio addressed (9.5:1 or lower) to allow for the lower octane of today's gas (combustion chamber cc's, dished pistons, cam choice, etc)?

If you're running over 9.5:1 cr with iron heads you will experience detonation and eventually hammer your rod bearings into oblivion. Is it possible to run 9.5:1 cr with iron heads? Yes, if the proper cam is chosen and your motor is in a perfect state of tune. All of the available "octane boosters" from the big auto parts stores are snake oil. Real TEL is illegal for use on anything other than "off road" use. Mixing pump gas with racing fuel is a viable alternative, but it's a PITA over time.

The only real alternative is to get your cr in line with today's fuel by either finding iron heads with larger combustion chambers, installing dished pistons or some combination of the two. Aftermarket aluminum heads are another option if you're so inclined. Cam choice is critical no matter which direction you decide to go. Anything other than this is just a band-aid, IMHO.

[loggerhead]

If you want to solve your problem NOW w/o trying a bunch of stuff that does not work,
you should go to www.torcoracefuels.com and get the "Accelerator Unleaded Race Fuel Concentrate". It comes in a 6-quart case. It is not cheap but the "per-quart" price can be lowered substantially by getting the 5 gallon pail instead. I used this stuff in my
462 Trans AM and it absolutely works!!! It will however turn you spark plugs orange.

David

[goathead455]

I have used NOS racing formula with good results.
I was on a highway trip and got some lousy gas and my GTO started to ping,I added the boost and the ping went away.

[CDN2PLS2]

Noticed a pump in Pontiac,Mich today with 110 at $6.99 a Gallon!

[performerrpm]

Originally Posted by CDN2PLS2

Noticed a pump in Pontiac,Mich today with 110 at $6.99 a Gallon!

wish you could find a pump around here with that.

[gloryrestoparts]

Originally Posted by loggerhead

If you want to solve your problem NOW w/o trying a bunch of stuff that does not work,
you should go to www.torcoracefuels.com and get the "Accelerator Unleaded Race Fuel Concentrate". It comes in a 6-quart case. It is not cheap but the "per-quart" price can be lowered substantially by getting the 5 gallon pail instead. I used this stuff in my
462 Trans AM and it absolutely works!!! It will however turn you spark plugs orange.

David

what David said. I use this stuff in my Olds W-31 10.6:1 motor when I'm not running straight 100 brand Rocketfuel or 110 and have zero issues. I mix it with 93 to bring it up to 104 and I've raced the car with that mixture too. Next spring I'll start to use it in the GT-37 as it'll get a new motor with at least 11.0:1.

btw, for those that don't know, backing the timing off to get rid of the ping will increase the temps.

[Jack Blum]

I get these from PPR:
http://www.dynotab.com/

[SWEETJUDGE]

Mark, due to my prostreet car i get 55 gallon drums of 112 octane. now in my judge its 10.75 CR with some carbon on top call it 11:1 she will ping all day long. i 50 50 with race gas & shes a hot little girl........she wakes up & is a screamer...BIG difference
contact WILL at G FORCE 203 367 0423 he gets 5 gallon & 55 gallon

[techteacher5561]

After posting my question on the previously mentioned links, I ponyed up and bought 2 quarts of the Octane Surpreme 130 from Batterystuff.com. Half a quart (16oz) to 16 gallons of fuel (93 octane) and it ran very similar to when I mixed 1 part 110 w/ 3 parts 93.
Sunoco 110 race gas here is $7/gal. ( Cam2 is $7.69 locally- I haven't tried the CAM2 yet)
It works out to be cheaper to buy the Octane Supreme.

Next I'm going to try Jack podell's TEL product.
I need to verify that what I'm reading in his advertisment is correct. His product- also "real" TEL claims a higher octane increase per ounce than the Batterystuff product.
One of the local pontiac guys swears by Podells stuff- only catch is it is sold by the case only- 12 quarts.

If you want to "try it out" get the 2 quart package from Battery stuff like I did and give it a whirl.
Good luck- post your experiences once you try it.

Howard