Went on the dyno this weekend...

[Kooldino]

Originally posted by tjalfe
the device sounds like a zener diode

Actually, that's exactly what I was going to use at first once I discoverd that they exsisted. I'd need a 250mW 4.7v one or a 500mW 5.1v one to do the trick.

However, I'm told that since they are not powered, they don't have a perfect curve and plateu (assuming you graphed it's input/output). Hence, a powered device is "better".

But if my current piggyback can do the trick, so much the better.

[gt40]

Ok, I can see how that works.
now what happens when you are above 5000 rpm and not into boost? you could be sending your engine into a lean condition.

luckily for me the only thing I had to do was just enter my new transfer curve in my computer and all was as it should be.

Calculation: total flow rate = 280cc*4+960cc=2080cc=198 lbs/hr
hp = 198lb/hr*.8 (duty cycle of injectors)/.6 BSFC=264hp (I had originally assumed .5 BSFC)

And actually .6 is generally accepted as normal for turbocharged engines.

[Kooldino]

Originally posted by gt40
Ok, I can see how that works.
now what happens when you are above 5000 rpm and not into boost? you could be sending your engine into a lean condition.

That shouldn't happen, since the MAF won't have topped out yet. It couldn't have seen the amount of air it did if it wasn't under boost. It will run as if it's stock at that point.

Calculation: total flow rate = 280cc*4+960cc=2080cc=198 lbs/hr
hp = 198lb/hr*.8 (duty cycle of injectors)/.6 BSFC=264hp (I had originally assumed .5 BSFC)

Yeah, it's actually closer to a .5BSFC.

BUT, my 280cc injectors are rated at 280cc AT 80% DC. So in reality they're "bigger"

And actually .6 is generally accepted as normal for turbocharged engines.

Yup. BUT, according to my dyno'd hp and injector size, I am closer to a .5.

[gt40]

That shouldn't happen, since the MAF won't have topped out yet. It couldn't have seen the amount of air it did if it wasn't under boost. It will run as if it's stock at that point.

of course, what was I thinking.

[DukeP]

Zooooomm..
Straight over my head.

(And Im even the son of a mechanic, heck, even my grandfather was a mechanic. Sigh.).

~~DukeP~~

[The Rock]

14psi?!?!!?! Maybe its just that I'm turbo-illiterate since they don't make turbos for my ride, but isn't that a LOT of boost? I'm assuming you've got a seriously upgraded engine?

Bart

[Kooldino]

http://forums.murc.ws/showthread.php?s=&threadid=46451&highlight=pistons

http://forums.murc.ws/showthread.php?s=&threadid=47424&highlight=pistons

[The Rock]

Wow!! I'm a car nerd and I somehow totally missed all these threads!! $2000 for an engine. Damn thats so cheap!! Sure wish BMW engines were that cheap. You are (or already have) upgraded the brakes to match the power right?

Bart

[Byock]

so, GT, what's your ride, and what do we have to do to get more pics of it?

[az]

Just cross the road at the right time and place and the rest of us gets lots of pictures with steel and lots of feathers

AZ

[gt40]

Originally posted by Byock
so, GT, what's your ride, and what do we have to do to get more pics of it?

nothing special looking,
1988 mustang:


Here's the race motor, that I've just pulled out ( had to get the car emmision tested )


Here's the original motor going back in - notice that this vehicle has absolutely NO rust whatsover:



And here's the only 4 cylinder vehicle I've ever owned:


And the only CAT I will ever own.


I am considering leaving the race motor out and finding a nice 68-69 mustang fastback to transplant it into. - I am getting too old to keep swapping the motor everytime I need to get emission tested.
Oh, and to all you folks that think I am spewing tons of pollution into the air: when this motor is in it it only ever goes to the race track and back, and the odd tuning run.

[Kooldino]

Originally posted by The Rock
Wow!! I'm a car nerd and I somehow totally missed all these threads!! $2000 for an engine. Damn thats so cheap!! Sure wish BMW engines were that cheap. You are (or already have) upgraded the brakes to match the power right?

Bart

Just better pads (Hawk) and Powerslot rotors. It has decent stoping power, but if I want to get REALLY nice brakes, it's $2K for the big brake kit. Ouch.

[Kooldino]

So what's she run anyways?

[Byock]

Nice!! I have always liked mustangs.

[gt40]

Originally posted by Kooldino
So what's she run anyways?

Best time so far 11.9 at 118mph - crossing at 7000rpm.
It could do a bit better I think, but never got a chance yet to play with the staging rev limit feature. I'e always used pump gas also.
with the 11:1 compression and some real fuel I should see mid 11's
the data logs give me about 425hp at 6800 rpm (normally aspirated)