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Discussion Starter #1
Do any of you guys used the 100 octane at the track? If so, do you run faster than using 93 or 92 tune. I currently have the evolution stage 1 package and purchase the 100 octane tune. Is it worth using it at the track or just stick with the 93 tune that I have in it?
 

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Discussion Starter #2
Do any of you guys used the 100 octane at the track? If so, do you run faster than using 93 or 92 tune. I currently have the evolution stage 1 package and purchase the 100 octane tune. Is it worth using it at the track or just stick with the 93 tune that I have in it?
I appreciate if someone would assist with the question. My GT 500 is ready to go:banana_hitit::banana_hitit::bluecap:
 

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The 100 octane wont help you without a tune. But, since you said you purchased the tune it should run faster, yes. I believe the 100 octane tune is just more timing than the 93 octane tune.
 

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higher the octane, faster you go
 

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Kent-1 here are a few things you should know before you spend any money on higher than normal octane fuels. First off lets understand what octane does. The octane rating is a measure of the resistance of gas to detonation. High-performance engines like ours typically have higher compression ratios and are therefore more prone to detonation, so in general we need a higher octane fuel than say a Honda. That’s why it’s recommend by the auto manufactures in a car like my GT500. A lower-performance engine like your Honda or typical family car will not generally perform better with high-octane fuel, since the compression ratio is fixed by the engines design. It’s important to understand that the octane ratings do not relate to the energy content of the fuel so a higher octane fuel will not make you go faster at the track. So then what good is a higher the octane fuel to us? Well, since higher octane fuel is more resistant to pining it will allow us to adjust our timing (AKA tune for it) to a higher than normal setting which in turn creates a higher compression stroke in the motor before the engine begins pinging. Doing that will produce more power which in turn will actually give you a better time at the track. I hope this helps you in making your fuel choices and tuning settings. So in closing if your tuner gave you a tune that requires 100 octane then you really need to use the 100 octane or you may see damage to your motor due to pinging.
 

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Discussion Starter #6
Honez-thanks for the excellent reply. I ordered some drag radials today and will make a couple of runs next week for test and tune at local track. I might as well put some race gas in the car and program the car computer for the 100 octane program. I am looking forward to running at the track. Thanks for all replies.
 

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I felt I should chime in here before you do some damage. Unless you drain out your existing fuel and put in only 100 octane fuel you're going to end up with a mix in your tank which will not be 100 octane and when you run the 100 octane tune, you will run lean. I wouldn't recommend that, unless you want to sell me a GT500 with a blown engine cheap! In which case go for it. If your car is a Vista Blue with Navigation, definitely go for it! :)
 

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Kent-1 if your really serious about getting this right then before you go to the track you should be on a dyno with a qualified tuner, a wideband, and a computer that can tell you what's going on with your motor. Once you have achived your best tune with the max timing and fuel curves and no pining then you can safely take it to the track and beat the piss out of the car. At least then you will know that if your track times suck its the driver not the car. LOL!
 

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Discussion Starter #9 (Edited)
Well I definitely do not want to hurt my car at the track, so I will just run the 93 tune. I was going to put the racing fuel (which is 110 octane) in the tank for a 50/50 balance with the 93 octane already in the tank-then put the 100 tune program at the track!

Car is red not blue BTW! Thanks!!
 

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Yeah, sorry, I'm only interested in blue. But seriously, I wouldn't risk it myself. The gain in hp isn't going to be worth the hassle or the money spent to run the higher octane gas. It only takes one time to burn up a piston.

I should also point out that the GT500 engine, though high-performance, is not high compression. Matter of fact it is extremely low compression. The static compression on the motor is only 8.4 whereas the 4.6 3v Mustang GT motor for comparison has higher compression at 9.8. The reason for that is the GT500 engine is engineered specifically for a power adder such as a supercharger or turbo which when given boost effectively raises the compression ratio of the engine which is why you need to run premium in it. That's also the reason why you generally can't take the stock Mustang GT motor much past 400-450rwhp on pump gas because you are limited by the amount of boost you can push through the engine because it is raising the compression ratio. Of course there's other reasons as well because since you would want much better internals in the GT engine which are already in place in the GT500 engine such as a better crank, rods, and pistons. Drop the compression in the GT engine and add better internals and you can then easily boost that motor up as well. It's all about how the engines are built and for what purpose. And lastly they need to be tuned properly no matter what.

I thought I'd edit and add a few more items of interest for comparison. The 03/04 Cobras with the 390hp 4.6 DOHC and supercharger had a compression ratio of 8.5 and the 03/04 Mach 1's with the 300hp 4.6 DOHC naturally aspirated had a compression ratio of 10. The closest naturally aspirated comparison I can think of to the DOHC 5.4 GT500 supercharged engine would be the Cobra R 5.4 DOHC motor which had a compression ratio of 9.6.
 

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Discussion Starter #11
:grinbiginvert:Well I will only run the 93 octane after all of this reading and advising. Now I wish I had not bought the 100 octane tune. However, my car is more for the street than drag stripe. I am not going to the drag stripe to run the fastest
time, but to have fun on a limited bais. When you go faster and faster, things start happening over time, you spend more money and things start breaking. I have anothe car to punish at the track and it is a 99 SS camaro and it is track ready.
 

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It's too bad you bought the tune, but at least you asked the question so now you can avoid any engine damage and paying for potential repairs.
 

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:grinbiginvert:Well I will only run the 93 octane after all of this reading and advising. Now I wish I had not bought the 100 octane tune. However, my car is more for the street than drag stripe. I am not going to the drag stripe to run the fastest
time, but to have fun on a limited bais. When you go faster and faster, things start happening over time, you spend more money and things start breaking. I have anothe car to punish at the track and it is a 99 SS camaro and it is track ready.
Uh....OK, better late than never. This time I'll speak up. With all due respect to previous posters, you will NOT "run lean" if you mix 100 octane with some 93 or whatever you had in it. You MAY however have detonation from a lack of octane to prevent it.

Consider this....if it's hot outside, forget running your car on a 100 octane tune with a "mix". You'll likely get some detonation, depending on how your knock sensors are set. If your tune is adjustable, pull a degree of timing in the middle and at the top.

You could also add a half can of Torco Acellerator to your tank and leave the timing as is. (Again, heat is the enemy, so it depends on temps)

I try not to use Torco because of what it does to plugs over the long haul. I try to get to the track with a 1/8 tank of 93 left. I put 6-8 gals of 100 race fuel in at the track. Shake the car a touch and load my race tune. Viola'.
No "lean" conditions, no detonation.

Have fun.

bj
 

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Discussion Starter #14
Uh....OK, better late than never. This time I'll speak up. With all due respect to previous posters, you will NOT "run lean" if you mix 100 octane with some 93 or whatever you had in it. You MAY however have detonation from a lack of octane to prevent it.

Consider this....if it's hot outside, forget running your car on a 100 octane tune with a "mix". You'll likely get some detonation, depending on how your knock sensors are set. If your tune is adjustable, pull a degree of timing in the middle and at the top.

You could also add a half can of Torco Acellerator to your tank and leave the timing as is. (Again, heat is the enemy, so it depends on temps)

I try not to use Torco because of what it does to plugs over the long haul. I try to get to the track with a 1/8 tank of 93 left. I put 6-8 gals of 100 race fuel in at the track. Shake the car a touch and load my race tune. Viola'.
No "lean" conditions, no detonation.

Have fun.

bj
Thanks for the reply! That is exactly what I wanted to here and someone that has experience using the 100 tune.

Well I can do this. Did you notice any improvement at the track with the 100 tune? Do you use it every time you go to the track?

Thanks for the reply.
 

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Thanks for the reply! That is exactly what I wanted to here and someone that has experience using the 100 tune.

Well I can do this. Did you notice any improvement at the track with the 100 tune? Do you use it every time you go to the track?

Thanks for the reply.
Clearly not all tunes are created equal. Jon Lund did mine. I have a 91, a 93 and a 100+ race tune. My race tune has a variety of little differences. For example, Jon was playing around with making the traction control a little more progressive. I don't use it but I have and it was better.

Using it normally (TC off), my fans work differently....I have my throttle by wire working a little more aggressively.....my tune makes +/- 550 at the tires. If you use any of the performance calculators, they show my car more like 575 or above since I turn 124mph trap speeds. So, yes, I always use it when racing.

As I'd said, I get there with a few gallons of 93 then mix 100 race gas in.
 

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Uh....OK, better late than never. This time I'll speak up. With all due respect to previous posters, you will NOT "run lean" if you mix 100 octane with some 93 or whatever you had in it. You MAY however have detonation from a lack of octane to prevent it.

Consider this....if it's hot outside, forget running your car on a 100 octane tune with a "mix". You'll likely get some detonation, depending on how your knock sensors are set. If your tune is adjustable, pull a degree of timing in the middle and at the top.

You could also add a half can of Torco Acellerator to your tank and leave the timing as is. (Again, heat is the enemy, so it depends on temps)

I try not to use Torco because of what it does to plugs over the long haul. I try to get to the track with a 1/8 tank of 93 left. I put 6-8 gals of 100 race fuel in at the track. Shake the car a touch and load my race tune. Viola'.
No "lean" conditions, no detonation.

Have fun.

bj
Bringing back this thread because I'm waiting on my 100 octane tune from Lund.

Planning on running Torco to get me to about 103 and running the 100 octane tune at the strip.

What timing does a 93 octane tune run versus a 100 octane tune?
 

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Bringing back this thread because I'm waiting on my 100 octane tune from Lund.

Planning on running Torco to get me to about 103 and running the 100 octane tune at the strip.

What timing does a 93 octane tune run versus a 100 octane tune?
Dumbest question ever............... :)

Before the "timing depends on a lot of things" response, your Lund tune should have 20* at WOT on 93 and he will most likely go to 23* on 100 octane.
 

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Dumbest question ever............... :)

Before the "timing depends on a lot of things" response, your Lund tune should have 20* at WOT on 93 and he will most likely go to 23* on 100 octane.
Hey now, you shush.
You answered my questions, that's all I needed :p
 
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