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R/Tony
12-23-2008, 02:27 PM
Hello !

Another question came here, I was wondering how much alky mix will be saffer for my setup:

2.5L Holset turbo (planning to use 40+psi)
forged end.
Megasquirt 4bar
8v head with 4th piston cooling mod.
and Im planning to use a Neon SRT4 timming map (its litle agressive)
Labonte meth kit with M8 nozzle.


Im planning to use M3 Methanol mix (50/50 water) with VP racing fuel Motorsports 109octane, its safe to use Methanol and race gas isnt it?

Im starting to see knocks on 16 17 18lbs more than less, so I will set the progressive kit on 17lbs to 40lbs of boost, well.. thats my plan, but im not sure if i will have problems with Methanol and the race gas.

Any thoughts ?

R/Tony
12-23-2008, 02:38 PM
Found a new release from VP :nod:

http://vpracingfuels.com/fuels_spec.asp

NEW! M5TM
M5 is simply the best performing methanol on the market. With its upgraded combustion additives, M5 will make more power than M3, i.e., 5-7% more power than standard methanol, while offering the same or better protection against detonation. Like M3, M5's improved vaporization offers a wider acceptable range of air/fuel ratios and tuning. It also yields faster combustion speeds which lead to closer EGT's from cylinder to cylinder, providing more consistent performance from run to run. M5 is not pure methanol and won't pass a water test.

Note: Available in 5-gallon pails and 54-gallon drums

so i will use M5 now, 50% M5 and 50% water, with race gas

I dont want to waste the engine :o

contraption22
12-23-2008, 03:09 PM
If you have a good intercooler, and enough fuel system capacity, you may not need the meth at all with that fuel.

Also, I am not sure that you will need and/or want the lubricants in M3 or M5.

R/Tony
12-23-2008, 04:00 PM
If you have a good intercooler, and enough fuel system capacity, you may not need the meth at all with that fuel.

Also, I am not sure that you will need and/or want the lubricants in M3 or M5.

I have a walbro 255 FP, and a set of NSRT Stage2 injectors (682cc) so i guess i have enuf fuel, but 40 psi of the holset are just too much air dont you think? and the SRT timing map is aggresive.

t3rse
12-23-2008, 04:05 PM
no way that the stock timing and stage 2s are going to support that much pressure...isn't going to happen. pump probably isn't up to 40# either, as that much pressure with even a smallish holset should be pushing 600 hp.

you are getting knock under 20#, which means that race gas alone will probably do some good, but the fact remains that you need to pull timing and you will hit this same wall further up if you don't solve it no matter how much race gas or methanol you stuff in there.

shadow88
12-23-2008, 05:48 PM
no way that the stock timing and stage 2s are going to support that much pressure...isn't going to happen. pump probably isn't up to 40# either, as that much pressure with even a smallish holset should be pushing 600 hp.

you are getting knock under 20#, which means that race gas alone will probably do some good, but the fact remains that you need to pull timing and you will hit this same wall further up if you don't solve it no matter how much race gas or methanol you stuff in there.

I agree, the srt-4 timing map should cause huge problems with the 8 valve head. Why not use a more conservative timing? Are you running mega-squirt?

R/Tony
12-23-2008, 09:14 PM
I agree, the srt-4 timing map should cause huge problems with the 8 valve head. Why not use a more conservative timing? Are you running mega-squirt?

well I can pull the timing advance a litle bit when the turbo its blowing air (above 100kpa's) and keep the timing numbers like that before the turbo starts to spool.

Yeah Im using megasquirt.

shadow88
12-24-2008, 12:32 PM
I'd be surprised if you could get more than about 15-18 degrees advance before the knock sensor gets all worked up. Is your MS set up to retard timing on it's own and if so where are you putting the threshold?

Aries_Turbo
12-24-2008, 06:48 PM
http://www.squirrelpf.com/bucar/ecu%20stuff/Total%20Timing%20Calulations%202_5L%203-bar.xls

this is a better way to determine timing for a 2.5L. start with this and add timing slowly till it knocks.

dont touch the big yellow box in the upper left.

put your RPM and KPA values in the other yellow boxes (convert KPA to PSI) and it will display the total timing value to input for that KPA and RPM point on the megasquirt map. (Total Timing WOT and Total Timing Part Throttle) use part throttle timing values in vacuum and WOT timing values in boost. this is based on the stock 2.5L swirl stuff and 12 deg base timing on the distributor so itll be safe to 20psi. i inputted the values for 15-29.2psi based on my car.

obviously you will have to experiment with values over 29psi.

if you dont want to waste an engine, this is a good place to start. youll want to implement some active knock detection scheme too. Frank and I will be working on my knock box over new years to try to get that to a point where people can use it soon.

Brian

johnl
02-17-2009, 09:55 PM
109 should do a good job of supressing detonation all by itself.

Adding 50/50 injection on top of 109 means you it'll be hard to build heat, absent big boost/advance.

As for the M1, M3, M5 discussion; I read the VP site's discussion as applicable to their methanol as a primary fuel, not as a secondarly detonation suppressant. There may well be additives in M3 or M5 that render that fuel incompatible with water. Do the additives dissolve, or separate, when mixed with water? Best to ask VP.

R/Tony
02-18-2009, 10:50 AM
I'd be surprised if you could get more than about 15-18 degrees advance before the knock sensor gets all worked up. Is your MS set up to retard timing on it's own and if so where are you putting the threshold?
Yea.. the active knock sensor system is already installed, but I havent checked if it works, Im starting to pull timing at 15psi to 30psi.

I just want to meet the theory here and then go racing more safe !


109 should do a good job of supressing detonation all by itself.

Adding 50/50 injection on top of 109 means you it'll be hard to build heat, absent big boost/advance.

As for the M1, M3, M5 discussion; I read the VP site's discussion as applicable to their methanol as a primary fuel, not as a secondarly detonation suppressant. There may well be additives in M3 or M5 that render that fuel incompatible with water. Do the additives dissolve, or separate, when mixed with water? Best to ask VP.

Thanks for your input, you know I just found this in the FAQ of VP site:

Q. Can M3 or M5 be used with a methanol injection kit?

A. I'd use regular methanol like VP's M1 for the injection. This is what I personally use. All you are using the injection for is to cool the air charge. This is how you get more power, because you can add more timing or boost with a cooler charge. M3 has a hydrocarbon in it and won't pull the heat like M1. M5 has a hydrocarbon and a combustion additive. I would definitely not use this. It could have bad results by combusting in the air inlet tube between the turbo and the throttle body. M1 is your best choice.

:clap: so I will use M1 :)