first theoretical power plot for a std 172

[Captain Slarty]

heres the first plot (All calculated from torque curve)

after refinement this spreadsheet will form the basis of the turbo mods and also will be used to estimate BHP and TORQUE with varying boost.

if you look at the right of the graph you should be able to decide WHEN to change gear for nest power out of gear and into new gear.

It is obvious from the torque curve that the VE of the engine is excellent.

http://homepage.ntlworld.com/captainslarty/172/plot1.jpg

Joe.

 

[Eddd]

Joe,

It was years ago now but when we used to run my F Atlantic A on the dyno my tuner was always showing me the BMEP for some reason. Is this related to the VE? Just trying to jog my memory a bit...

 

[BenR]

very nice!

so thats why you got up at 5am!

could you send me a copy, i want ot see if mycalculations that i have been doin are correct. i think i might be a bit off..and i want to see how you use VE.

Cheers mate!

ncie to know my 122@wheels does make roughly 162bhp@fly.

 

[BenR]

very nice!

so thats why you got up at 5am!

could you send me a copy, i want ot see if mycalculations that i have been doin are correct. i think i might be a bit off..and i want to see how you use VE.

Cheers mate!

ncie to know my 122@wheels does make roughly 162bhp@fly.

 

[Captain Slarty]

Hi M8 !

BMEP (Brake mean effective pressure) is related to rpm and hp (for one version of the formula that I use - this is output in PSI)

formula

BMEP=(hp * 13000) / (Capacity in litres * RPM)

es, it is therefore related.. and a good measure of engine efficiency.

it is definitely adding to the spread sheet (as I have now done - see new plot) as it will be extremely important when forced induction is used.

Joe

http://homepage.ntlworld.com/captainslarty/plot2.jpg

 

[Captain Slarty]

Ben - on its way.. but very BETA.. !!



Joe

 

[BenR]

we can all see the little dip @ 5000 or so rpm. I dont nkow if you put it there on purpose, but my power graph looks very similar!!!

VVT?

BTW, why is it called VVT? shouldnt it be mroe aling the lines of VCT (cam) since valve opning/closing is just a function of the cam timing?

 

[Captain Slarty]

Hi Ben, I dont think it is vvt, but am still looking into that one.

I think VVT is the best term (Varible valve timimg)

In this contect it would refer to the cycle timimg.. the duration has to stay the same.

but, as you rightly say.. VCT would be as accurate

Joe..

 

[Rich-D]

BenR -

Well, apparently the VVT kicks in at a mere 1200rpm mate!!!

Or so I have been reliably informed...

 

[Captain Slarty]

oh, and Ben, can you possibly send me the plots you printed off ??

Joe

 

[BenR]

yeah, ill send the plots. but it was done in a hurry.
its bhp (poo not very good) against mph of the rollers.
luckily its @ the wheels.
he didnt have time to hook to the coil and since i was getting it free, i didnt want to bother him too much. but ill make sure its revs/torque adn revs/bhp nextime.

i will have to send them next week as i have left them @ the engineernig company.....doh!

 

[telford_mike]

Am I the only one who feels distinctly inadequate reading threads like this?? I struggle to program the video!

 

[Captain Slarty]

LOL Mike.. dont feel like that.. Brun was texting me on the moby and I have no idea how to read or send a text msg !.

Neither can I program a video - Jayne does that

Joe..

 

[BenR]

VCRS!!!!
there hard, but these new darn fangled digital cable machines!!!
how do you frikkin program you channels!

 

[Rich-D]

Joe -

LOL

That would explain why you didnt reply to my text message and you ended up ringing me!


p.s Just got new front brakes and a nice hybrid turbo for the 5!!!

 

[Man-Chun]

http://www.rapidline.com/pc.htm

That program would be cool if you didnt want to calculate too much Dont know how much it costs tho.

Chun.