Diablovt750

Fixed some band aid since pics also, such as the water coupler on hot side of the intercooler, etc.

greenday3437

iTrader: (2)

Well since my last update (if anyone cares) I've served my term in the military and moved back home. (DFW area of Texas)

I've also done a quick (not really) and crapp job of painting the miata, it looks like hell but still looks a lot better than three shades of red and one shade of red faded to pink.





Sorry I know the pics suck, they were taken on my iphone, it's not much to look at anyway.

I've also gotten to car running well and tuned pretty good for 10psi, as well as gotten to meth/water injection running, turning on at 7psi.

The past few weeks I've been turning up the boost a few psi at a time and tuning for the new boost level, today I turned it up to 14psi and did a few runs with the autotune feature, it's running really well.

I am left with a few questions for you guys though.

I'm not sure how much is too much, do I keep turning up the boost until my injectors (550cc) are at 80% DC? Or is my setup (stock pistons, forged rods, meth injection) not able to handle that should I just aim for a certain boost level and call it a day?

My other question is about timing number when in boost while meth/water injection is spraying. I'm currently running the Y8's/diyautotune base map hybrid from a thread a long time ago.

This one:

I've been thinking though I should be able to get away with more timing up top due to the lower CR than his as well as the meth injection (I'm currently running 30% meth and 70% water, may change do 40/60 soon) I was thinking something like this in the top three rows and leave the rest as the hybrid table:



I know going to the dyno and tuning for real on a dyno is the best way, but right now I can't afford that, I was just wondering if you think I could safely get away with running those numbers with the meth injection, if not I guess I'll leave it how it is for now.

Here is the first run I did today at 14psi, and yes I know the turbo is super laggy, but it's staying for now so I'll just deal with it until I make a new mani, I may switch turbo's then maybe not.



Lemme know if you have any suggestions, thanks.

gospeed81

iTrader: (51)

It's generally accepted that stock pistons with forged rods are good up to about 300whp...if there's absolutely no det. This was the recipe I was using for my built motor that I never finished. Wish I could provide more reference, but everything out there is pretty anectdotal. There are a few guys in that 250-300whp range on this type of setup.

Timing with WI is the same as always...tune to MBT or det threshold. Get some det cans...you'll be surprised how far you can go with the meth injection. At that point I'd stay well away from anything that resembles det though. Det cans can be had or made cheaply...and you're shooting in the dark (or trusting pre-made maps) otherwise.

johnmatt

iTrader: (8)

I was just wondering the other day what happened to you man. Glad to see you're back and the car is still alive

greenday3437

iTrader: (2)

Yeah I keep thinking I need to make some det cans, the only problem I see with it is wearing them while driving surely has safety/legal concerns, and I'm not sure how many of my friends I trust driving it while I listen. Guess I gotta do what I gotta do though.

Perhaps, I should go make some det cans tonight and start stepping my advance up a few degrees at a time until I get too nervous to up it anymore.

I dont really want to start advancing timing until I get my boost controller set where I want it to be, does 18psi sound like a safe-ish level for the street?

greenday3437

iTrader: (2)

Hah yeah I lurk daily, just been to busy to give any updates really, what with moving/job finding blah blah blah. Thanks for the kind words

GIGAPUNK

I'm running a whipple at 19 psi on a stock '95 longblock. I had to pull 1.3 degrees per psi of boost to keep detonation at bay while running 93 octane. But my intercooler sucks donkey dong and I regularly see 250+ intake air temps. In my lowest cell I'm running like 6 degrees of advance.

this is when I was running the link at 9 psi



and this is last week with the AEM EMS well tuned for 19-20 psi



I'm running RC550s and at max duty cycle I see 84%, however I am using an aftermarket fuel pressure regulator at rising rate @ 1:1 with a base pressure of 52psi.

With water meth you basically have 106 octane rating plus cooler intake air temps. I was told by corky bell that you don't see too many reliability problems on a 1.6 boosted to the sky, and 1.8s till above 15 psi. I've been running around learning to tune on mine and it's still going strong.

You can definitely go well above 90% duty cycle, as long as you're not doing any land speed runs. High duty cycle is only a problem if sustained for a long time. Seriously it will only be in a few cells over 7000 rpm and over 20psi of boost, if you raise your base fuel pressure to say 4bar and use a rising rate. You'll never spend more than a few seconds in those cells. So max out those injectors!

You can also experiment with running abit more water/meth. Meth is fuel too! And the bigger your water/meth jets, the less duty cycle you'll need out of your injectors. Just remember when tuning that the reduction in needed fuel is max when the water/meth first triggers and tapers to redline.

johnmatt

iTrader: (8)

Or buy my 750s. I dare you to max those out on stock pistons

greenday3437

iTrader: (2)

Haha no thanks I'll just max out my 550s, should bring me near the 300 mark, I think I'm going to make some det cans tonight if I can find all the stuff I need laying around, I think I still need to find a copper lug or something for the motor end, does everyone here attach it to the top motor mount bolt?

GIGAPUNK

my bosch knock sensor is on the passenger side engine mount bolt.

greenday3437

iTrader: (2)

6 degrees seems super low, have you though about doing water/meth injection and bumping the timing way up? I'm sure there's gobs of power to be made by doing that.

GIGAPUNK

Your dead right about there being more in my combo. Water/Meth is most likely in my future. The timing is really not as bad as it sounds. When I first started tuning it kinda freaked me out. But pulling 1.o to 1.5 degrees per pound of boost is pretty standard. And I'm only pulling 1.3, remember this is a positive displacement supercharger making 20psi of boost! If I could get the intake air temps down reliably I'm sure I could add another 10 degrees. But right now it is what it is. Water meth could be worth a ton. They say you get about 1% increase in hp for every 10 degrees you reduce your IATs. If I drop from my current 260, to 100 with water meth I'd pick up 16% on 248 rwhp! That alone would be 39 hp! Then add the higher effective octane of the water/meth plus the cooler IATs the extra timing could be worth another 20hp! Ugh.

Here's some proof of what I'm saying. It's a forged 1.8 with a whipple at 18psi. Two psi less than me and 50 more hp. I think that our superchargers are sucking 20-30 hp at this level.

greenday3437

iTrader: (2)

Wow yeah I'm surprised you aren't running it already