Supra Forums banner
1 - 18 of 18 Posts

·
[H][K][S] whore!
Joined
·
437 Posts
Discussion Starter · #1 ·
Im currently hitting 1.1 bar (~16lbs) of boost in 3rd gear (auto) with my BPU+ setup. Without any fuel control, whats the most amount of boost I can safely run without having to worry about detonation and all that good stuff while on good ole' CA 91 octane?
 

·
Espresso Connoisseur
Joined
·
1,636 Posts
Do you have a front mount? I'd leave it right there @ around 16 psi. 91 Octane is just plain crap.
 

·
[H][K][S] whore!
Joined
·
437 Posts
Discussion Starter · #4 ·
Yep... BPU with front mount and cam gears, so BPU++ if you wanna get technical. I have my EVC EZ, but I havent played w/ the settings yet.

I'll keep it at 16... :rant:

Thx GUys
 

·
Espresso Connoisseur
Joined
·
1,636 Posts
MKIVdan - why do you need the WG spring mod? Don't you overboost like the rest of us BPU guys?
 

·
Ex Supra Owner
Joined
·
1,077 Posts
i got a solid 23psi out of it to redline, and i ran 100oct 24/7 in my old bpu car. Now i have a single with C12 race gas 24/7. Honestly if you have daily beater just run race gas 24/7. In a bpu car you only need 100oct its really worth it for maximum power on tap all the time. Race gas is like crack, once youve felt it YOU keep going back!
 

·
Espresso Connoisseur
Joined
·
1,636 Posts
I run 100 octane on occasion since my set up likes to overboost. I'd have to agree...everytime I get on the c16, it's almost impossible going back to 91... :(
 

·
aKa Blk96SupraTT
Joined
·
3,866 Posts
But how much are you guys paying for the C16??? I mean at $3.49 a gallon for 91 its hurting. I cant see myself pumping up 18 gallons of C16 at say $6.99 per gallon, thats like $125 for one pump; and that'll last for about 250miles. I'm only guessing on the price of C16 since i havent personally pumped it before but when i pumped 100 it was pretty damn expensive.
 

·
Ex Supra Owner
Joined
·
1,077 Posts
I buy 55Gal drums of C12 every month. 5.50/gal. BTW TunaRollZ- you dont need C16 in a bpu car, 100oct is perfect. The faster and hotter you can burn the fuel without detonation is the more power you are going to make.
 

·
Espresso Connoisseur
Joined
·
1,636 Posts
I never ran c16 on the Supra. I ran it on my previous project cars...mainly the 300zx and gsx.
 

·
On a stick...
Joined
·
144 Posts
So running 20 psi max on a auto mkiv with exh, dp, FMIC, with bored out stock twins would not be recommended without a stand alone?
 

·
Registered
Joined
·
3,658 Posts
suprahh said:
So running 20 psi max on a auto mkiv with exh, dp, FMIC, with bored out stock twins would not be recommended without a stand alone?
20psi on the stock twins on 91octane is just plain STUPID. Unless you are trying to blow your motor.
 

·
Registered
Joined
·
374 Posts
you can run max boost on 100 octane but it may be risky if you don't check you a/f ratio to make sure your fuel system is up to par as higher milage cars often have issues that don't allow full fuel flow potentiontial. As far as 91 octane. 91 octane is piss water. No joke. Despite what the people here say, if anybody has an ear tuned to hear minor knock you will hear a 100% bone stock supra ping on 91 octane especially on a hot day. My black supra with 16K miles did this and so does my current baltic blue which had 32k when I picked it up. Personally I wouldn't go over the ~1bar of boost of a straight BPU setup (no boost control) on 91 octane except for cold nights when you can probably get away with 16-17psi with some timing still being puled by the ecu.

By the way the knock is rarely audiable at full throttle it is usually when boosting partial throttle in the mid range and the 1st turbo around 3000-3300rpm. On the next hot day (ie tommorow) If you turn off all the air and radio to make the cabin quiet (and don't have a loud exaust) hold your head as close to the windshield as possible and then boost (preferbly uphill) part throttle still on the #1 turbo only at around 3000rpm and I gurantee you that you will hear some knock on straight 91.
 

·
Registered
Joined
·
1,602 Posts
supradup said:
16 psi is fine. anything over 18 and timing gets pulled a fair amount and hardly any hp is gained.
Timing gets pulled substantially even at stock boost if your running 91 octane! It will never cease to amaze me way more don't run water injection. Is it that much of mystery to you all?
 

·
Registered
Joined
·
446 Posts
MtFujiSupra said:
Timing gets pulled substantially even at stock boost if your running 91 octane! It will never cease to amaze me way more don't run water injection. Is it that much of mystery to you all?
yes, meth/water injection is the answer to our shitty gas. I get 5 gallons of meth for only 12 dollars and it last a very long time. Do the math and order yourself a kit.
 
1 - 18 of 18 Posts
Top