cygnusx1 Posted October 14, 2004 Share Posted October 14, 2004 I am about to sign up to bring my Z to Limerock Park for a time trial session on the road course. Just to be safe I was thinking about backing my timing down from 27 to about 25 and maybe turning the boost from 14 to about 12. I was also wondering if any of these "octane boost" additives really would add a margin of safety; reducing possible detonation under track conditions. Race fuel would be ideal but being a street car, I run 92 octane pump gas. The time trial is with EMRA at Limerock on Oct. 29th. I think my Z is going to fall into the Tuner class. I have never driven on a track before but I cant wait to not have to worry about mail trucks, school buses, oncoming traffic, and pedestrians. Quote Link to comment Share on other sites More sharing options...
Guest 77vegasz Posted October 14, 2004 Share Posted October 14, 2004 Some octane boosters attack rubber tubing after a while. If you run them all the time they can cause problems with rubber fuel line. Union 76 in Nevada sells 100 octane pump gas. It is very expensive, around 4.25 a gallon, but that might be a better bet if they have it in your area. Jon Quote Link to comment Share on other sites More sharing options...
Dan Baldwin Posted October 14, 2004 Share Posted October 14, 2004 If you've never driven on a track before, leave the boost turned down and don't worry 'bout octane boost. You'll have your hands PLENTY full learning to carry speed through the Uphill and Downhill without the extra power Also, consider that you're going to be running the engine HARD, no reason to try to experiment with a setting you haven't proved under more benign conditions. Think I'd experiment at the dyno with timing/boost level/octane boost before turning it up at the track. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 14, 2004 Share Posted October 14, 2004 Octane boost is usually a mix of Xylene and Tolulene which is paint thinner. These solvents are available from the paint supply store for ~$8/gallon. The octane booster is sold in such small quantities that it basically does nothing. Most claim to boost octane 1 point, but if you look into it you'll find that they don't boost from 91 to 92 octane, they bump it from 91 to 91.1 octane. These chemicals will eat hoses if you run them straight, but they are fine and won't cause any problems up to about 30% mix in gas from what I've read. In fact, both Xylene and Tolulene are already in the gas you get at the pump, just in lower concentrations. I've run 5 gallons gas to one gallon Tolulene for a while and had no problems whatsoever (mixed with 91 that gives about 95 or 96 octane). Do a search here for octane booster or google it and you'll find home brew boosters using the above with a little mineral spirits and ATF mixed in. I do not understand why you would increase the octane and then retard the timing and cut back the boost. If you aren't having problems with detonation I'd be increasing the octane and running more boost and more timing. I'm not a turbo guy, but I don't see why the length of the probably 20 minute session would matter in terms of needing increased octane... Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted October 14, 2004 Author Share Posted October 14, 2004 Well, yeah I agree, If I can guarantee 95-100 octane in the tank I will leave all the parameters alone and drive it how it is. I just was thinking that an ounce of prevention could save me a flatbed fee back to my house from the track. Quote Link to comment Share on other sites More sharing options...
Dan Baldwin Posted October 14, 2004 Share Posted October 14, 2004 Whoops, pardon me, I though you were thinking of INcreasing boost and retarding timing. Backing off both can't be a bad idea if you're unsure you'll have the gas you need to run at 14psi/27deg. Have fun at Lime Rock, I'll be there with COMSCC on Nov. 19/20. BRRRRRRR! Quote Link to comment Share on other sites More sharing options...
yo2001 Posted October 14, 2004 Share Posted October 14, 2004 Too much octane without tuning will slow you down. I would get a base run on pump and go from there. Dan, I like your avatar, Goya is my favorite print maker. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted October 15, 2004 Author Share Posted October 15, 2004 Slowing down may be a good thing the first time on the track with my baby. Yeah, I suppose a "resistance to ignition" (octane), increase would yield either a slower burn or a delayed ignition causing less power. I think I will just take my timing back to near factory and drop the boost down to about 12psi to be safe while I learn to brake, turn-in, apex, and exit corners properly. I REALLY would like to keep the car in one piece for the duration so I will be "slow" while I learn to drive for sure....at least this time. Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted October 15, 2004 Share Posted October 15, 2004 I think if your gonna bring up the Octain you should just run as much race gas as you can. Your combination at that boost shouldn't need more than 100octain. If you do run race gas run as much timing as you can, you'll feel the car alot slower if you dont run up the timing or more boost. From what I know about you and your car I would say its probably fast enough as is maybe setting the boost to 12psi if it doesnt throw your tune off would be a better idea. As is I bet you'll give them hell. Good luck and let us know how it when't, glad to see your gonna be let out of your cage. Alex C Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted October 15, 2004 Author Share Posted October 15, 2004 Hey, Alex how are you? Your turbo is putting down some good power and I don't want to blow the motor all to bits. I think I will settle for about 12psi or so and use the street gas; 92. I know it works for 14psi on the street. I will be out of the cage Goals: 1) Learn to drive track 2) Keep motor intact 3) Stay out of the tire barrier after Big Bend, on the inside. (if you know Limerock you've seen cars in that barrier) Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted October 15, 2004 Share Posted October 15, 2004 I'm doing OK, running the retail outlet of the wholesaler I worked for, Horsepower Sales. All is well I'm in charge of making things happen at this new store and its a bit of a up hill battle but I am doing what I like so I shouldn't complain. Good to hear your car is doing what it should I'll see you on the board. Alex C Quote Link to comment Share on other sites More sharing options...
Clifton Posted October 16, 2004 Share Posted October 16, 2004 I always run race gas at the track even though I could probably get by with a mix of pump and race. I run alot more boost though. If you run 14 psi on pump but 15-16 causes knock I would run a little C16 in there to up the octane. If it knocks while you are in a session you just wasted one session, chances are you won't hear it either unless it's bad though. Don't know what turbo you run but if it has anywere near the lag mine has I would not retard the timing. It will give you a little more torque coming out of a turn especialy if your revs are a little lower than ideal. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted October 17, 2004 Share Posted October 17, 2004 I agree picking up a gallon of toulene (provided you can find it... some people have a really hard time with this) and throwing that in one full tank (or one per every tank you plan on running??) would definately give you an increase in safety margin for very little money. Those off the shelf octane boosters do usually contain the same 'ingredients', but one small bottle of that off the shelf stuff isn't enough to make an appreciable difference in your overall octane. One full gallon of toulene to 10 gallons of fuel will give you a 4 point octane increase, if what I read was correct, so from 92 to 96 octane. Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted October 20, 2004 Share Posted October 20, 2004 my car is inop-but when ever i run a open track day i use race gas.usually 10 gallons of union76 110 leaded with the rest pump 91.but usually it 100+ degrees it thunderhill.the hardest part of track days is learning the track.best way to learn the track-forget you are on a race track.pretend the track is a mountain road you drive to work.concentrate on using the whole track while driving smoothly.learn where the bumps and patched spots are. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted October 20, 2004 Author Share Posted October 20, 2004 Sounds like fun...I live on a road resembling a track. 75% of my commute is on roads that wind and pitch like a track. I am hoping that hours and hours of commuting "practice" on these roads has made me a natural line picker, apexer, and overall car dynamics natural. We will see. I hope to have the confidence to push the car, but also to have enough sense not to overpush the car. The area in which I live could easily be mistaken for a tarmac, pro rally track. Yes, there are jumps also.... I save those for the WRX. Quote Link to comment Share on other sites More sharing options...
John Scott Posted June 14, 2006 Share Posted June 14, 2006 I agree picking up a gallon of toulene (provided you can find it... some people have a really hard time with this) and throwing that in one full tank (or one per every tank you plan on running??) would definately give you an increase in safety margin for very little money. Those off the shelf octane boosters do usually contain the same 'ingredients', but one small bottle of that off the shelf stuff isn't enough to make an appreciable difference in your overall octane. One full gallon of toulene to 10 gallons of fuel will give you a 4 point octane increase, if what I read was correct, so from 92 to 96 octane. ..priced toluene lately? Also getting hard to find. Last I checked $15+ a gallon. So much for cheap home brew. Here in Colorado, one month ago 112 octane was less than a 1/3 of this price, no guessing, blending. Doesn't take much to add a safety margin. Three gallons added to my 6 remaining in tank of pump yeilded close to 100 octane. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted June 14, 2006 Share Posted June 14, 2006 John Scott are you going to the Colorado State Patrol track event with the Z car club of Colorado?! Id love to run with ya Quote Link to comment Share on other sites More sharing options...
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