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What can you say from looking at it? Is there anything? I mean, the A/F ratio is good, a little on the rich side, but that's ok. Would i be able to do anything about that? The hp peak was around 5.2k... That's lower than it should be for a stock b20b... And my car has a free flowing exhaust, but i guess not free flowing intake, quite yet... The torque peak seems to be around 3k rpm, i needed to have started the dyno at lower rpms though, because it seems like right when i got on it i had my max torque. Here's my dyno sheet again:
http://www.super-crush.com/gallery/albums/klrdynoday/kyle_2.jpg
My friend had the same "problem" with his Nissan 240SX. We were also wondering how to evaluate his dyno sheet and find some ideas on what he can do for it. How can we smooth it out, it looks like it's bouncing quite a decent amount, is there anything we can do for that? Does that mean anything? What about leaning it out? is there anyway we can do that? Here's his sheet:
http://www.super-crush.com/gallery/albums/klrdynoday/Zak_1.jpg
Thanks!
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Kyle - '68 Volvo 142 w/71 b20b and m40...
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posted by
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Wed Dec 31 18:00 CST 1969 [ RELATED]
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I was wondering what a few runs like that costs at that shop?
Thanks
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Wed Dec 31 18:00 CST 1969 [ RELATED]
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http://www.super-crush.com/gallery/klrdynoday
Don't ask about the first video. That was the old motor, with the DGV, and we got it to blow flames, and then when we tried for the camera, it didn't do it anymore... Don't bash me on it, i know it was dumb. That motor and carb are gone. This one isn't going to get as much abuse, well, not like that anyway. Listen to my exhaust in the dyno clips, it sounds very relaxed, like it's only revving up to maybe 4000 or so... Head work and hotter cam anyone? Or is it really just that quiet of an exhaust... The smoke that's REALLY bad on one of the runs was because the guy messed up and he made me leave it in gear so i was at like 5krpms and just letting my engine slow down the rollers... So, is that valve guides(or seals, or whatever)?
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Kyle - '68 Volvo 142 w/71 b20b and m40...
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posted by
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Wed Dec 31 18:00 CST 1969 [ RELATED]
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A change from the stock exhaust might move the powerband down the rpm scale a bit... but the peak values you're getting are higher than what I'd expect from a stock motor. I wouldn't complain.
Note that while the SAE specs have the HP peak at 5800, the more realistic DIN specs -- which take into account things like the engine having to spin a fan, alternator and water pump -- have it at 5500.
It is odd, though, that the torque and HP peaks are 200 rpm low from those DIN values, and also that the pull stops at 5800 instead of the 6000 you thought you ran to. Can their tach be off by 200?
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Wed Dec 31 18:00 CST 1969 [ RELATED]
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The tach is the wierd thing, i had to disconnect my tach because it might have been one of the sources for my random ignition problem(more on that in a later post). So i was using their computer screen's tach. I did pull up to about 5800 one of the runs i think, but i thought i went all the way up to 6 on the other two. I don't know. Looking at it again, it seems that my hp peak is at 5100 almost. The engine fan i have on there i know saps up a lot of power, it is clutchless, so it is spinning quite fast at 6k rpms. I should take it on the dyno again after i take it off(and get an elec. fan) and get the timing set to where i want it. But, i'm quitting my job and that won't happen for a while. Next year i guess? I'll have a better intake setup then too, right now it isn't setup how i want it, it's just setup so i can drive it around with a filter in there...(and it's an older dirtier one).
As for the power levels being decent for stock ratings, of that i'm glad, maybe the new plugs, magnecore wires, modded SUs, and free flowing exhaust are helping a bit.
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Kyle - '68 Volvo 142 w/71 b20b and m40...
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posted by
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Wed Dec 31 18:00 CST 1969 [ RELATED]
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"The torque peak seems to be around 3k rpm, i needed to have started the dyno at lower rpms though, because it seems like right when i got on it i had my max torque."
Dunno what you mean: the runs start at aprox. 2k rpm.
Stock B20B should have torque peak @ 3500 rpm, hp-peak @ 5500 rpm. Seems close enough to me.
cheers, ben
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P131, '65, B20B+M47. P131, '69, B20E+AW71L+LSD. (www.tinustechniek.tk)
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Wed Dec 31 18:00 CST 1969 [ RELATED]
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In my Haynes manual it says the SAE reading should be 118hp at 5800 and DIN 100hp at 5500. What's the difference between these two readings and how do they compare with whatever method we use today for measuring output?
Yeah, a couple of my runs start at a little over 2k, but by the time the engine get's up to full power it's right where my max trq. ratings on the sheet are. I'm wondering if the engine was getting to full possible power(at that given rpm) at a sooner rpm my trq figures might be different...
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Kyle - '68 Volvo 142 w/71 b20b and m40...
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posted by
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Wed Dec 31 18:00 CST 1969 [ RELATED]
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In my Haynes manual it says the SAE reading should be 118hp at 5800 and DIN 100hp at 5500. What's the difference between these two readings and how do they compare with whatever method we use today for measuring output?
In a nutshell, SAE is for the bare motor without any parasitic loads, while DIN is for a motor driving a fan, alternator, waterpump, and whatever else is hooked to it. The actual units of HP are the same -- DIN is just the more real-life measurement.
Of course you were measuring HP at the driven wheels, which is always much lower because there are friction and loading and inertial losses in the driveline. You wheel HP and torque numbers are excellent.
Yeah, a couple of my runs start at a little over 2k, but by the time the engine get's up to full power it's right where my max trq. ratings on the sheet are.
Think about this... you're measuring how the engine accelerates. DynoJets can't measure steady rpms, only how fast rpm increases against a load. The chart shows the result. If you'd started from higher rpm, the peak values would still be the same (or maybe lower, as the carbs would have less time to respond before hitting the peak torque and the mixture might be further off).
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Wed Dec 31 18:00 CST 1969 [ RELATED]
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Wed Dec 31 18:00 CST 1969 [ RELATED]
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Usually their done in 4th, because that's the most direct path through the driveline and usually -- but not always -- yields the highest numbers. I have heard of a few cases where some car or other got slightly higher numbers in 3rd, but not usually.
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Wed Dec 31 18:00 CST 1969 [ RELATED]
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Wed Dec 31 18:00 CST 1969 [ RELATED]
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That's a lot of smoke, ayup. Did it smell like oil? What's odd is that on the first run on the movie, there's one pretty good puff while you're accelerating, not just when backing down.
Are you getting oil deposits on the plugs?
(BTW, that doesn't sound to me like you're only pulling to 4000 rpm, or whatever people were telling you...)
Darn, wish I coulda been there.
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Wed Dec 31 18:00 CST 1969 [ RELATED]
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I dunno, yeah, i saw that puff too, and no, i haven't seen dirty plugs. Well, not really. I'll check and take some pics on thursday when i go home and use my dad's new dig. camera. Did it smell like oil? I'm not sure, i'll have to ask Cameron, as you can see him smelling it there... As for the sound, well, the exhaust doesn't seem very mean, just kinda calm and very nice sounding, but not as MEAN as i'd like it =D. The front of the car was very loud, and it seems like you can hear the intake in the movie, but from the front of the car it didn't seem like it as the fan took over all. Also, there is some sound coming from the tires spinning on the rollers as well. And yeah, i wish you coulda been here too. Sean from down here in corvallis, with his p1800 was going to dyno his built b20 with dual webers on it, but he blew his third or fourth rearend when leaving his driveway, or was it the gas station while still in corvallis...
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Kyle - '68 Volvo 142 w/71 b20b and m40...
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