ayousef

Trying to figure out what would be the highest boost PSI I could run on a 9.0:1 CR 427 with 305cc Mast heads, small duration cam and a whipple 4.0 blower and pure 93 octane pump gas no meth.

Please guys I dont want anyone to school me on "boost is not the measure of power etc..." lol

Also what would be a realistic power goal for such a set-up on pump gas alone through an M6

joshtownsend

iTrader: (16)

that blower aint going to make enough to worry about it.. I don't see more then 12 psi which is fine on that setup

ayousef

aha

CALL911

iTrader: (17)

You didn't mention, but you may want to consider an intercooler as well.

MattSapp95_T/A

iTrader: (35)

I have ran my 9.1 motor up to 16lbs on pump gas without any issues... 93 octane and 16 degrees of timing and the largest front mount intercooler I could fit...

Prob could have ran more but didn't want to get greedy..... now with my meth kit pushing 20psi......

zapp109

iTrader: (13)

why not add a meth kit to be safe?

joshtownsend

iTrader: (16)

probably cant get it that easy.. look at his location... also, thats a big motor with high flowing heads... boost levels will be lower then on say a 6.0

btw.. I ran 26 psi on 87 ... with meth...

ayousef

I haven't heard of any PD blower run without an intercooler since temps at cruise get to 80 degrees celcius try WOT and see what happens!

So yes its intercooled

ayousef

Thanks man this is the only post that answers the question

ayousef

We do have meth and I might put in a meth kit but I would like to see if it satisfies my need for speed on pump gas alone then race gas alone.

Meth does cool much on PD blowers but does act as a ln octane booster obviously.

Also I thought your initial post was sarcastic but maybe not? You realized I mentioned a big 4.0 whipple blower lol

joshtownsend

iTrader: (16)

if you can get meth.. thats the way to go.. its $4-$6 gallon here where as 93 is $4-$5 here and you use gas weather you are in boost or not... 87 is about $3 ish.. so it just make since to run 87 and meth because once you spray enough meth, your octane level will be well above 91-93 anyways. So many people waste their money on 93 and there really is no need for it.. if your not getting knock.. then you can run anything you want until you get knock..its really as simple as that. Only "tuners" and "shops" make it out to be black magic.

I ran 10 psi and no meth on stock block ls1 with a small intercooler and did just fine in Texas heat on a P1 setup

ayousef

well 93 is a full 6 points of octane more than 87, so 93 plus meth equals a MUCH higher octane equivalent vs 87 + meth, which means that you can either run more boost, or more timing and that makes more power. Whether the power is worth the extra cost of the 93 is where it becomes subjective, but id NEVER run 87 octane in my car, not even in a lawn mower

joshtownsend

iTrader: (16)

Racing fuels, avgas, liquefied petroleum gas (LPG), and alcohol fuels such as methanol may have octane ratings of 110 or significantly higher.

haha you think you need??... Do you really think your motor knows the difference between 87 and 93 when its mixed with 110? There is a point that octane does not matter and does not matter even if you added 40 degrees timing.. it just simply burns off at that point.. its a liner scale and anything above is simple wasted.. If i could find 80 i would run it in my car.. and I can promise you i have way more money in my car then you do yours. Link i said.. 26 psi, 87 octane, 10.4 compression... zero knock at 17 degrees timing at 7300. numbers don't lie.

Like i said earlier, that blower aint going to get anywhere close to the limit with that pullley and i doubt it would with a 1" pulley on it. Its a heat box and not efficient by any means. TO answer the first question, max the blower out because you would be fine.

ayousef

You're funny

whipple 4.0 flows 2500cfm, do you want me to translate that into HP?

I ran a TVS2300 blower to 12psi on a 427, you're saying ill max out a whipple 4.0 at 12psi? lol. Also your post suggests I mentioned a pulley size, I never did mention a pulley. Not sure where you're getting your info or logic from.

Also Im not sure where you get your math from, assuming when meth kicks in it accounts for 30% of the fuel ingested by the engine, that means 70% of the fueling comes from whatever crap you have in the gas tank so:

70% of 93 octane + 30% of meth = 93(0.7)+110(0.3) = 98.1 equivalent

70% of 87 + 30% of meth = 87(0.7)+110(0.3) = 93.9

so what you're trying to say is, 4 points of octane make no difference, to each his own i guess

joshtownsend

iTrader: (16)

Your right.. im wrong.. but you wont see me asking any questions on a board because im the guy doing it.. not talking about it.. When you make over 1200 on 87.. or 93 or 110 for that matter , let me know... because I did

Tell you what, Ill be in Abu Dabi sometime next year, ill come see this heat box scream and make all of about 850.

6D9 Matt

Interested in this topic as well... subscribing.

mchdg86

iTrader: (3)

Wow you sound like a dick head. You do know that a 4.0 whipple flows about the same as an F2 procharger which can make more than your 1200 hp?

CALL911

iTrader: (17)

To the original question in the title, it really varies with CR. A high CR will not allow to run as high boost as a lower CR given the same parameters (intercooling, meth, E85 ect.). You want higher boost levels safely without any of these, then drop the CR. Or you can have a higher CR but not as much boost. Its all a matter of how you want to do it, and how far away from detonation you want to be.

To the OP, I think you'll be fine with your setup, and your goals.

wilfredes

Interested in this topic as well.

ayousef

Woah glad someone else noticed lol not sure what's up with the dude

For those who subscribed this thread might get lost by the time I find out how much boost it will take on straight pump, but I will post back might take two months.