Warning!! Detonation on the dyno.....

So I found a place in San Antonio with a dyno and checked it out today. I wanted a baseline here in texas so I would have a better comparison after the hondata flash. So I get on the dyno and tell the guy to pull in 4th gear. The car gets to about 5.5k and starts to ping (BAD!!!!) so the operator gets off the gas and was like what octane do you run with this thing. I told him 87, to which her replies, you can't do that with 11:1 compression, and I told him that it was not 11:1 but 9.8:1. He's like, isn't this the VTEC motor? At this point I'm upset, and having a hard time convincing the guy that it is indeed okay to run 87 octane. So they will let me re-dyno the car on monday after I get better gas. The thing is, I run 87 from Chevron every day and never had a problem. Maybe I got bad gas, maybe not. Maybe my car advanced the timing thinking I had a different octane, I don't know. But I do know that I won't be runing 87 any more. :'( :( :mad:

Here's the dyno. Notice the cirlces where the car started to retard power.
http://www.trailingsilence.com/dave/Dynos/pingdyno2.gif

Damn, that sucks. I'm always afraid to run 87, even though I know it's supposed to be perfectly fine and not make much difference at all. I always put in 95, even though it's probably been sitting in the station's tanks forever.

It will be very interesting to see your before and after!

There was a post on here a while ago talking about 3rd vs. 4th gear in our cars. Neither is exactly a 1 to 1 ratio, but 4th is slightly overdriven, so maybe that placed an excessive load on your motor coupled with the 87 octane. You might try a third gear pull with 87 octane. Good luck.

why cant anyone believe what has been posted so many times, OUR ep's can run on 87 but they will not operate at full potential with that gas (if the computer senses detonation it will retard timing to an EXTREME level affecting performance greatly!!).. run some 91 or 93 youll see a difference, before you tell me im wrong run a couple tanks through. then post a reply -- Joe

i believe ya Joe ;)

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Originally posted by 02blksi
why cant anyone believe what has been posted so many times, OUR ep's can run on 87 but they will not operate at full potential with that gas (if the computer senses detonation it will retard timing to an EXTREME level affecting performance greatly!!).. run some 91 or 93 youll see a difference, before you tell me im wrong run a couple tanks through. then post a reply -- Joe

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except that I've already done dyno pulls with 87 with out problems, which is why I had 87 this time too.

I also have done pulls in 3rd and 4th with no problems either. As far as the octane issue, I think that increasing the octane a few #'s will give a few (ie 1-3 hp) ponies. What I saw today was not a loss of 1-3 hp but detonation and extreme power loss. like I said I've done the dynos with 87 then with 91 and then 101 and saw the difference. Had I lost some power since my last dyno with 91 I would not care much. But this was soo strange! I'm not sure what my point is, except that I'm baffled at what happend today.:(

The gas was probably not quite up to snuff....I don't know exactly what level of quality Chevron is(I forget what brand they're sold as up here but it's not under Chevron!) but even good brands occasionally have stations that haven't kept their gas quite up to snuff....

Happens occasionally...but running 89 should give you a slightly better safety margin =P I'm gonna start running 91+ though starting with my next tank.

Damn Dave! Whoa! I just saw this. That's freakin nuts. I never had a problem with 87, although the past 5 tanks I've been using 93. Ouch! Have you thought about going to honda about this? And were you using you stock intake.
By the way, where in san antonio is there a dyno?

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Originally posted by 02SilverSiHB
Damn Dave! Whoa! I just saw this. That's freakin nuts. I never had a problem with 87, although the past 5 tanks I've been using 93. Ouch! Have you thought about going to honda about this? And were you using you stock intake.
By the way, where in san antonio is there a dyno?

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I thought about going to honda, but I don't know what they can do since the car seems to run fine. I checked out the plugs today and this seemed to be okay. I was using my short ram intake on the dyno. The place is off of Nacodages and 410 team extreme racing

They told me to call back on monday and try the dyno again with different gas. I guess I'll just run 89/93 from now on.

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Originally posted by Cone Killer


I thought about going to honda, but I don't know what they can do since the car seems to run fine. I checked out the plugs today and this seemed to be okay. I was using my short ram intake on the dyno. The place is off of Nacodages and 410 team extreme racing

They told me to call back on monday and try the dyno again with different gas. I guess I'll just run 89/93 from now on.

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how much was it? I think I might try and go with you on Monday, I'm dying to see what I'm getting with my crazy mods :D