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Discussion Starter · #1 ·
Hey guys, I ran some race gas tonight in my Supra. I raised boost to 18-19psi. I noticed that every time I would start to build boost, the car would hesitate, but not violent like fuel cut. More like ignition was breaking up or something in that feel. Any idea’s on what caused it? Never had the problem on 93oct pump gas. Thank you.

I am BPU+++ Tuned
 

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fresh plugs...NGK 6097's, try them at the stock .0315 gap and gap them down until it misses....should be ok at the stock gap though.

Jason
 

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Boost Junkie
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Did you mix it with pump or run it straight. At 18-19 psi on the stock twins you really only need 100 octane to take full advantage of the timing you could run so 116 is over kill.

You may have also gotten some bad gas.

Steve
 

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Discussion Starter · #4 ·
I mixed 5gal of race gas with a little over 1/4 of 93oct pump gas that was in my tank.
 

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Discussion Starter · #5 ·
i will also try new plugs. thank you.
 

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New plugs, tone down the octane a big (you might want to give C12 a try or another gas with a lesser octane). You really don't need to run at full C16 of a 2/3s mix with the stock ecu and stock twins.
 

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Supra Owner Since 1996
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I agree it is your plugs if you have never gapped them down after going BPU. A lot of cars will not run well on C-16 if not correctly tuned for it. They have seen better results only backing down to C-12 or similar. Still over kill at BPU levels
 

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putting about 6 gallon of 100 octane in, should it or shouldn't it effect boost? also should one reset the ECU ? every variable are left alone such as plugs, boost control setting, etc...
 

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Discussion Starter · #10 ·
thank you everyone. i am tuned on a stand alone but only for 93oct. so i should go with NGK 6097's, should i gap them?
 

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This is a stupid question but something just clicked, my friends supra with single and fuel was running AEM but he switched to the stock ecu w/MAP Ecu,, whenever he would shift gears at full throttle it would hesitate for a moment. Was this fuel cut?
 

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Supra Owner Since 1996
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7THSIGN said:
thank you everyone. i am tuned on a stand alone but only for 93oct. so i should go with NGK 6097's, should i gap them?

Yes you should always gap your plugs reguardless. For BPU on the 6097's go to .028-.032 mm.
 

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'95 TT
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Or if you don't want to gap, just get some NGK 3330s... the gap they come with works perfectly on my BPU car.
 

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Discussion Starter · #14 ·
Thank you guys. Put in some NGK 3330s and car has no more hesitation. My OEM Denso plugs had it.
 
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Try VP CSP unleaded , or VP MS 109 unleaded. Good stuff. A little pricey but keeps my BPU running good. My .02

Mike B
 
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