learned an important lesson last night..

[larryd]

C16 and 40 Degree weather dont mix on my car..

Last night I went to the track. I got there and had no gas so I put in 3 gallons of C16. I turned the boost up from 15psi I had been running on the street to 23psi and made no other changes which lead to bad knock that entire run.

I tried different things on every run from leaning the car out more and more and upping and lowering the boost anywhere from 17psi to 28psi and the car just did nothing but knock.

I got into a converation with someone at the track about the effects of 116 octane gas on cold nights and the fact it can hinder performance more then help because its octane is so high that its not as easily combustable and wont allow the car to fire properly.

Anyhow to make a long story short I made my best pass of the night at 17psi (lowest boost of the night) ending up in a 13.68 @ 108 with a 2.3 60ft time. Everytime I tried turning the boost up the car just pulled the timing as much as 10 degrees in 3rd gear.

Now to the part that pisses me off, I leave the track and hit up the gas station. Filled up the tank with 93 octane and left the boost where it was on my last run at 1.4 bar (21psi) and ill be damned if the car didnt pull 10x harder on 93 then it did on 116. So my night at the track was ruined while at the same time it was semi comforting since I didnt break 108mph or 13.6 all night..

 

[supereclipse]

That really sux. better luck next time man.

 

[SPEEDY]

Originally posted by larryd
C16 and 40 Degree weather dont mix on my car..

Last night I went to the track. I got there and had no gas so I put in 3 gallons of C16. I turned the boost up from 15psi I had been running on the street to 23psi and made no other changes which lead to bad knock that entire run.

I tried different things on every run from leaning the car out more and more and upping and lowering the boost anywhere from 17psi to 28psi and the car just did nothing but knock.

I got into a converation with someone at the track about the effects of 116 octane gas on cold nights and the fact it can hinder performance more then help because its octane is so high that its not as easily combustable and wont allow the car to fire properly.

Anyhow to make a long story short I made my best pass of the night at 17psi (lowest boost of the night) ending up in a 13.68 @ 108 with a 2.3 60ft time. Everytime I tried turning the boost up the car just pulled the timing as much as 10 degrees in 3rd gear.

Now to the part that pisses me off, I leave the track and hit up the gas station. Filled up the tank with 93 octane and left the boost where it was on my last run at 1.4 bar (21psi) and ill be damned if the car didnt pull 10x harder on 93 then it did on 116. So my night at the track was ruined while at the same time it was semi comforting since I didnt break 108mph or 13.6 all night..

I can kinda relate to this. I have been running 110 leaded race gas for awhile now, and I have noticed on very cold mornings when I go to start my car to warm it up it has a hard time of starting up on the first try. Sometimes it takes several times of me turning the ignition over for it to finally start. Then... when I put 93 back in it starts up on the first try everytime.

 

[ILOSE]

A hotter plug should help out. I have had to do the same thing in the colder weather.

 

[SPEEDY]

Originally posted by ILOSE
A hotter plug should help out. I have had to do the same thing in the colder weather.

Good point! That seems very logical, especially when the air temps outside are much colder. I'm currently running 20 to 22psi on my FP Big28 using the NGK BPR7ES plugs gapped at 0.28. I do get a crappy idle sometimes from them, and I noticed my car idled better when I use to use the Bosch Platinums, even though they are not supposed to be good for turbo applications. I'm just wondering if in the winter time I could use the factory plugs, and get away with running high boost levels, and in the summer time switch back to the BPR7ES plugs. What do you think?

 

[Violater101]

go to BPR6ES which is a colder plug for wintertime applications. I have yet to run racegas in my car yet, so I can't really add any imput :< If the car was pulling more than 5 degrees of timing(cel on), I would get off gas in a heartbeat, but thats just me personally. Hopefully you will get it worked out before the dyno day you are going to.

 

[larryd]

yeah im not to worried about it, we will figure out what the problem is with the car sooner or later..

 

[CBgst]

I wonder if that was what my problem was last time I went to the track. The car seemed to pull so much harder the night before on 93 pump. Could that be the reason for the lower mph. I ran 13.6 @ 102. 3 weeks before and with out the fmic I ran 13.8 @ 102. I didn't matter how much I turned up the boost or how I set my afc it didn't seem to pull as hard as should have been.

 

[cucumber]

It's ok Larry.

You'll figure your car out one day soon enough.

 

[larryd]

yeah right.. like in the next lifetime maybe.

 

[HighPsi91]

C16 is good stuff but I think it is a bit overkill for 22-23psi. You really dont need it. I would try something in the 110-112octane range. bpr7es plugs should be fine. I would stick with them especially if your gonna run 20+psi. br7es would be my personal choice, although they will foul a bit easier.

 

[cucumber]

Originally posted by larryd
yeah right.. like in the next lifetime maybe.

Someone needs an e-hug.

 

[larryd]

yeah, no #@%#@%#@%#@%..