How many LBS of boost on 91 octane - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Spike913 · 12-16-2005, 08:05 PM

I wish we had 94 octane in CA, but how high can you boost with 91 octane?

im running 13 lbs on the PE1420 untuned

Spike913 · 12-16-2005, 11:14 PM

ok high can you boost before detitonating, with all tha mods
FMIC, 550cc injectors, walbro fuel pump etc. and stock sr20 internals

ppl say 20 lbs with RAS ans stiffer valve springs

nrg · 12-16-2005, 11:15 PM

tune it and you can boost higher. boost depends on how good the tune is. not by the octane. octane is only 20% of the problem on boosting. it's called denation.

HIGHMILEHATCH · 12-17-2005, 10:46 AM

It's called detonation.

I would stop listening to the people telling you "20 lbs with RAS ans stiffer valve springs". That doesn't make any sense. Stiffer valve springs are necessary when upgrading cams. RAS prevent the rocker arms from flying off at high rpm. Neither which have any affect on how much boost you can run on a given octane. You mention you have 550cc injectors. What is controlling them? Please don't tell me stock ECU.

wootwoot · 12-17-2005, 12:35 PM

^^^bingo. I still highly recommend putting RAS in as soon as possible

12-16-2005, 08:05 PM	#1
Spike913 Join Date: Sep 2004 Location: California Posts: 10 Trader Rating: (0) Feedback Score: 0 reviews	How many LBS of boost on 91 octane I wish we had 94 octane in CA, but how high can you boost with 91 octane? im running 13 lbs on the PE1420 untuned

12-16-2005, 11:15 PM	#3
nrg Zilvia FREAK! Join Date: Mar 2004 Location: CA Age: 40 Posts: 1,571 Trader Rating: (1) Feedback Score: 1 reviews	tune it and you can boost higher. boost depends on how good the tune is. not by the octane. octane is only 20% of the problem on boosting. it's called denation. __________________ driftingisgay.com

12-17-2005, 10:46 AM	#4
HIGHMILEHATCH Zilvia Member Join Date: Jun 2003 Location: PA Age: 44 Posts: 182 Trader Rating: (3) Feedback Score: 3 reviews	It's called detonation. I would stop listening to the people telling you "20 lbs with RAS ans stiffer valve springs". That doesn't make any sense. Stiffer valve springs are necessary when upgrading cams. RAS prevent the rocker arms from flying off at high rpm. Neither which have any affect on how much boost you can run on a given octane. You mention you have 550cc injectors. What is controlling them? Please don't tell me stock ECU. __________________ www.street-solutions.com www.evans-tuning.com

12-17-2005, 12:35 PM	#5
wootwoot Post Whore! Join Date: Jan 2004 Location: sarasota florida biatch Age: 39 Posts: 3,850 Trader Rating: (0) Feedback Score: 0 reviews	^^^bingo. I still highly recommend putting RAS in as soon as possible __________________ I'm from Florida so I'm probably a bit more strange than you

12-16-2005, 11:14 PM	#2
Spike913 Join Date: Sep 2004 Location: California Posts: 10 Trader Rating: (0) Feedback Score: 0 reviews	ok high can you boost before detitonating, with all tha mods FMIC, 550cc injectors, walbro fuel pump etc. and stock sr20 internals ppl say 20 lbs with RAS ans stiffer valve springs