wil afm be ok

tony h · #1 08-12-2007, 06:23 PM

hello i,m a bit new to wi if just turbocharged my e30 325 bmw using the standard afm and ecu will it be ok to run a 50/50 methanol mix through the afm or is there a possible chance it could damage it or could i just go as close to the tb i,m using it mainly as an anti knock rather than power increase ,any suggstions ?

keithmac · #2 08-12-2007, 08:12 PM

I`d personally put the nozzle(s) after the AFM, methanol is corrosive and I wouldn`t think it`d do the AFM any good?.

tony h · #3 08-12-2007, 08:33 PM

thats what i was thinking, do you think it would be ok near the tb because its not really metered by anything, i assume its alot more important to get the correct nozzle size ?

keithmac · #4 08-12-2007, 08:48 PM

Most people put a single nozzle before the TB to give the mixture time to disperse into the air stream, how much liquid do you plan on injecting?. I found I only had to start trimming fuel back when I went up to larger volumes of methanol, 900cc/min.

I found port injection worked a lot better for anti-knock, but it`ll take 6 jets and a lot more plumbing to do it.

tony h · #5 08-12-2007, 08:58 PM

i,ve worked out (probably wrong) I need a .4 nozzle flow rate of about 160 which i think is still a bit high because i,m still running standard injectors 149 cc seems a bit measley to me gonna get bigger injectors when the boost goes up but gonna start off slow and build up gradualy ,i hope

keithmac · #6 08-12-2007, 09:09 PM

Are you sure they`re only 149cc/min? seems very small to me for a 2.5l engine?.

You could be crafty with the WI, if you do need more fuel up top you can use the methanol as extra fuel on boost with the added advantage it has a very good octane rating to resist knock.

I run 6 X 450cc/min fuel injectors on my 3l twin turbo, but by the time I`m at 11psi half my fuel is coming from the methanol injection, found this was the best way to stop the engine knocking (reported on the datalogger).

If I did my system again I`d have left the stock injectors in as I`ve trimmed the fuel map back that far they`re not really needed..

tony h · #7 08-12-2007, 09:25 PM

yeah apparentley they are 149cc ,does seem very low to me as well ,but had a look on the net and thats whats come up a couple of times, i thought maybe its because its a n/a engine ,who knows ? So if ive got this right i can get round the lean mixture at boost problem by cheating and (experimenting)using various meth mixes ,best bet using multi port i guess ? or do you reckon i can use single untill the boost starts creeping up?

keithmac · #8 08-12-2007, 09:35 PM

If you use multiport only you`ll have to be very carefull about making sure you don`t have a nozzle blockage as this will lean out 1 cylinder and could lead to a piston melting.

I run 6 port 0.3mm nozzles, a 1mm nozzle after the rear turbo and a 0.9mm nozzle before the throttlebody, that way if I get a clogged port nozzle it won`t be a complete dissaster.

I also run an electronic boost controller that I`ve wired up to cut bost if the AFR leans out over 11.5:1, so if I run out of methanol or there`s a blockage the engine will be safe.

Other people with the same car as me use only one or two nozzles and over 1l/min of pure methanol with good results, I think methanol vapour is better at flowing through log style manifolds than plain water.

tony h · #9 08-12-2007, 09:44 PM

so a primer pump and six nozzles should keep me on top of fuel supply and anti knock issues,?

keithmac · #10 08-12-2007, 10:04 PM

Should be a good start, I ended up going with a Shurflow pump for higher flow but I`m beating the engine to within an inch of it`s life at the moment.

Just put a few pics of my install up if you want a look, http://www.aquamist.co.uk/phpBB2/vie...442&highlight=.

An ERL pump with primer was good for 450-500cc/min with 0.3mm nozzles on my setup, I used a Ford remote windscreen washer pump for my primer off e-bay and it worked very well.