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Discussion Starter · #1 ·
I have recently replaced my fuel filter and found that my detonation problem has ceased. Before replacement, I ran on 93 with detonation under full boost. I just came back from the station where I put 5 bones worth of 89 and took the car up to the stock boost setting. there was no detonation. Obvoiusly higher boost will require higher octane, but I wondered what you guys were running.
 

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Discussion Starter · #2 ·
Never run anything less than Super with a turbo. That is why the turbo has a detonation sensor on it. I drive on if I can't get at least a 92.
 

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93 octane, always. I try not to run race gas so I don't have to worry about resetting the boost once I'm back on the street. Might look into/experiment with supplemental alcohol injection to get around that problem. Just goes to show the importance of having a fuel pressure gauge you can read while driving. I'm sure your problem was a loss of pressure while driving and at full throttle. a pressure check at idle would not have revealed the clogged filter. That's how pistons get holes in them. Get some kind of dial a boost so you can adjust to the different levels of gas you may come across. a knock detector may not be a bad idea to help get the longest use out of your motor. You can't depend on your ear to hear knock, especially at the higher boost levels (+10PSI). By the time you hear it it's pretty heavy detonation.
greg
71 240z
 

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RE: Gerg, do you have a f press perm mounted?

Or are you talking about temp mounting it until you get the correct setting? I just bought one to hook up the Bell regulator and was considering mounting it permanently. Can't put it in the car though so that relegates it to the cowl. Isolator is too costly.
 

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RE: Gerg, do you have a f press perm mounted?

Anytime I have a problem that may be traced to fuel delivery I check fuel pressure under full throttle. If I have to I will tape a gauge to the windshield to do it. On one car I have a mechanical gauge on the A-pillar. I have an isolator for it as well. I don't have one in the Z yet. Still putting in the interior and haven't picked a place out yet. You can get electrical gauges that are pretty good now, but the expense is still the same. Still you need one for serious motor tuning. Any car I'm going to push to the limits will have at the least a fuel pressure gauge and a EGT or A/F meter. All are needed for the motor's safety as well as to use to properly tune a motor. You will definitely need at least a temporary one to insure you are getting full and consistent pressure using the rising rate regulator. The higher pressures the Bell regulator creates really puts a strain on the pump. A good way to boost the stock pumps output is to "hotwire" it. I'll do a seperate post on hotwiring the pump.
greg
71 240z


Opie83zxt wrote:
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Or are you talking about temp mounting it until you get the correct setting? I just bought one to hook up the Bell regulator and was considering mounting it permanently. Can't put it in the car though so that relegates it to the cowl. Isolator is too costly.
 
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