Reaching MBT
 

Is it possible to reach MBT without the need for WI?
Reason i ask is - Pre WI i reached 192bhp, AFR,s were nice 12.5- 12.9, and timing was well advanced up to knock point (using J&S) pulled back a tad.
Took it to the dyno last night and fine tuned the AFR,S and with the WI set to come on at 5psi ,i pushed up the timing a little more- result was no knock but no increase in Overall BHP.
I then switched off the WI ,and repeated the run, same result (no power gain/loss).I pushed the timing up a little more and we lost BHP, added another 2deg and lost even more.
When i went back to my original timing map i gained back the power i had lost by previously advancing the timing.
Dyno operator suggested that i had reached MBT (with no WI), and by switching on the WI was indeed making the charge cooler- but i coulndt take advantage of it because when we advanced the timing we started to lose power.
Base timing of 14 deg,Running a fairly aggressive timing map adding all the way from +7degs idle - 2000, +4 degs 2000- 3500rpm, +3degs from 3500-5000rpm, then +5degs 5000-redline.

Charge temps showing 160degF (although suspect a little heatsoak at sensor), ambient air temps 50degF.

9:1 compression ratio.

Any comments/ideas?:confused:

it's absolutely possible... it depends on the motor (even among same motors since some are knock prone).

that means you can now figure out a way to use the WI to increase boost!

I thought it ment that i had reached "my limit" and that no amount of more "tuning " would yield any power.
Cant get anymore air in (maxed out on both pullies), i can get more fuel in if i wanted (but need the appropriate proportion of air).

Its no big deal , just was looking for a second opinion really:)

So I understand correctly, you are running a bade timing of 14 degrees BTDC, and *adding* an additional three to five degrees of advance?

I'd love to see your timing map. Is this all in the EMB, or is the J&S doing boost retard?

Correct - not pulling ANY ,all my timing advance is done by EMB , and its not the latest version of J&S - so it only pulls timing (if /when it detects) from its sensor ,bolted onto side of block.

how many hp are you pushing the m45 doesnt flow terribly well
you might be at teh flow limit of the SC and not the tunning

http://not2fast.wryday.com/turbo/maps/M45flow.gif at 10 psi the m45 flows like 300 or so cfm this wont support alot of hp maybe 260 or so chp

192bhp
http://i12.photobucket.com/albums/a2...lacedyno-1.jpg

is that with correction. you might be hitting the 200 hp wall everyone else with a m45 runs into time for a mp62 for real power

Yep- thats with correction- och its no big deal, i,m happy with what ive done up to now:) .
Its all been interesting and fun:bigtu:

Dude. Would you be willing to share your ignition map, or the .EM file? I'd love to see what you're doing with that.

That is impressive with the M45. I would be very happy with that. Here is my question, I am in the process of increasing the boost on my M45 system. I am running a 62.5mm pulley, about 8psi. I have supra injectors at the house, 150mm BBK, and I am waiting on a new fuel pump to come in. I also have the WI, which has controlled the ping just like I wanted it to do. Would I be able to get close to those numbers running a powercard or will I need to upgrade to the EMB? I have dibs on a bipes for timing control, and I will ditch the MSD once that comes in. Maybe this isnt the place to ask this question, feel free to move it if necessary. But I was just curious. Miata.netters annoy the crap out of me, so I never post Q's on that board. Most M45 questions on there lead too, the M45 is too small blah blah blah, get a M62, blah blah, dont bother......ect.

If i remember correctly you cant add timing with Bipes - so in that respect no, i,m not sure if a power card will be sufficient for 12psi-maybe i,m not sure.

An yeh get a MP62.....:) - JUS KIDDIN:nono:

i THINK EMB,s are fairly inexpensive these days anyway -and much more flexible than bipes/powercard combo

If i can run it on stock ecu with WI at 13 psi no problem then you can run it with your electronic gizmos.

Well, I am looking to the bipes to be an improvement over the MSD that I currently have. My concern is fueling with the powercard. They "say" that the powercard has whatever built in already, but when you read on .net, you will have people slam it and say it doesnt work over 6psi, which I already know is not true. My AFR's look all squigly....This is a Dyno done on a dyno dynamics back in the late summer here in Tampa. Dont Laugh at my wimpy 150.5...

you are still 12 or so -1 so i dont think you would be to fucked up trying to up it abit, just keep an ear out for ping and see if you notice any improvement.

Alrighty then. Let's see what happens. Thanks guys.

If it starts to go wrong all you have to do is lift. if you dont then well you know what will happen but lifting cures all the ills. Until you realy fix them.

I think hes got a good point, you might want to go like 3 - 5% leaner because it will raise combustion chamber temps, add more compression, but increase the likelyhood of knock so you would not be able to run as high of timing. I would be interested to see how thatworked out.

Yeh-if that means injecting pre-blower i would like to - but ive got an TDR i/c and dont know if it would be a good idea -maybe the water may "pool" in the I/C ?