Pontiac - Boost Turbo, supercharged, Nitrous, EFI & other Power Adders discussed here.

          
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Old 09-06-2019, 02:46 PM
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Default Octane requirements for nitrous and high SCR?

New build is a 434 with ported 670 iron heads at 9.8:1 compression. Lunati 231/239/110 on 104.5 ICL. With an intake valve closing of 65.5* ABDC, the DCR should be about 7.8:1.

What octane fuel should be used with a 150 shot of nitrous? Single stage plate under a Q-jet on RPM intake.

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Old 09-07-2019, 10:30 AM
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Hmm, I sense some hesitation to answer this one. So let me ask another way: Can I run a 150 shot on 93 octane pump gas, or do I need straight VP110 LL?
OR, am I limited to a 100 HP shot on pump gas?

Assume engine is sealed up well and tuned properly.

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Old 09-07-2019, 11:54 AM
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If it may help,
I ran a 9.5:1 412 250cfm 6X head with 230/236 110 ls installed at 106 hf cam on 92 octane. 150 shot and pulled 4 deg. Of timing without issue.

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Old 09-07-2019, 04:10 PM
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I have a 461ci 11.3 to 1 pump gas (93 octane) motor with a 150 shot . But i have a separate fuel pump and cell with 108 that mixes with the 93 for the NOS. Works great.. Never tried it with straight 93. Id be skeptical just like you.

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Old 09-15-2019, 10:35 PM
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I ran a 462 with 9.5 comp. and a 275 shot on 92 octane with 8* out and
no problems, I was using a separate pump just for the nitras.
I've always run two pumps on my car for nitras. and always pulled 8*
and haven't had a problem yet. Hope this helps.

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Old 09-15-2019, 10:37 PM
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I've run more comp. with this combo too.

GT.

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Old 09-16-2019, 03:36 PM
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Blueghost, How big a cam were you running? Do you know the adv duration and LSA? Trying to compare intake closing event to what I have.

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White '67 LeMans 407/TH350/Ford 3.89... RIP
Red '67 LeMans. 407/TH400/Ford 3.25
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Old 09-17-2019, 11:37 PM
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Quote:
Originally Posted by chiphead View Post
Blueghost, How big a cam were you running? Do you know the adv duration and LSA? Trying to compare intake closing event to what I have.
There were deferent ones. I'll get the cam cards out tomorrow and let ya know.

GT.

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Old 11-22-2019, 01:12 AM
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Quote:
Originally Posted by chiphead View Post
Blueghost, How big a cam were you running? Do you know the adv duration and LSA? Trying to compare intake closing event to what I have.
Man I had forgot all about this.
I'll be in my garage tomorrow and get some of this info for ya, Sorry bout dat.

GT.

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Old 12-03-2019, 11:59 PM
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Sorry I will get it eventually for you.

GT.

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Old 12-05-2019, 03:45 AM
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FWIW, my old Discomobile was pushing 11.5:1 CR with iron heads and I ran VP C-16 racing gas in it, spraying up to a 250-HP shot. No issues

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Old 12-05-2019, 02:00 PM
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Good info guys, keep it coming.

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White '67 LeMans 407/TH350/Ford 3.89... RIP
Red '67 LeMans. 407/TH400/Ford 3.25
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