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dartsteve 10-01-2012 12:34 AM

hp question
 
just took car to dyno, not pleased with the numbers
just looking for some input
500hp at 5200rpm
here is the combo

500 ci mopar
12.5:1 cr
700 lift cam prostock roller lifters
port and polished aluminum heads
1.5 roller rockers,
bird catcher with alky
38 degree timing
msd 7al2
the lamda was .7 on both sides
egt ranges 990-1040 F
5000 stall converter, JW ultraglide, strange 9" with 4.10 progears
33x15.5 slicks

i know it was running rich but power should be much better
the first time i went to dyno(different one) i made 610hp at 5000rpm before trans issue.(bad pump)
thanks for the input

curtisreed 10-01-2012 05:05 AM

The EGT numbers look ok but the Lambda number seems really rich. Here are some numbers I have for conversion from Lambda.

Lambda alcohol gas

1.000 6.450 14.700
0.990 6.386 14.553
0.980 6.321 14.406
0.970 6.257 14.259
0.960 6.192 14.112
0.950 6.128 13.965
0.940 6.063 13.818
0.930 5.999 13.671
0.920 5.934 13.524
0.910 5.870 13.377
0.900 5.805 13.230
0.890 5.741 13.083
0.880 5.676 12.936
0.870 5.612 12.789
0.860 5.547 12.642
0.850 5.483 12.495
0.840 5.418 12.348
0.830 5.354 12.201
0.820 5.289 12.054
0.810 5.225 11.907
0.800 5.160 11.760
0.790 5.096 11.613
0.780 5.031 11.466
0.770 4.967 11.319
0.760 4.902 11.172
0.750 4.838 11.025

roadkill2 10-02-2012 06:04 AM

Again, not being a wiseass, but . .

Tire guages aren't the same, one reads one thing, the next may be a half pound different. Same with Dynos . . It's all relative. When you changed Dyno's you started over . .

Jus' a SWAG here, but take 2 out of it, lean it out two steps and try it again. Dunno what yer air is but I've never seen many 500" alky engines that liked more than 33-34 of lead . . 'Course, I've always dealt with blown alky engines so there may be some difference.

Take it to the track, as I said in another thread, the race track is the most honest Dyno ever created . .

maxpower671 10-02-2012 01:08 PM

listen to Roadkill2
 

Originally Posted by roadkill2
Again, not being a wiseass, but . .

Tire guages aren't the same, one reads one thing, the next may be a half pound different. Same with Dynos . . It's all relative. When you changed Dyno's you started over . .

Jus' a SWAG here, but take 2 out of it, lean it out two steps and try it again. Dunno what yer air is but I've never seen many 500" alky engines that liked more than 33-34 of lead . . 'Course, I've always dealt with blown alky engines so there may be some difference.

Take it to the track, as I said in another thread, the race track is the most honest Dyno ever created . .

gotta agree again! wow, great advice 8)

-it sure does sound rich with those readings, as roadkill2 sez, why not lean it out and see if it responds ET wise..
-also agree on taking a bit of timing away to start with..you can always play with that once you get the fuel closer..

dartsteve 10-02-2012 02:39 PM

I think im going to stay from the dyno for awhile.
Just want a guestimate of what it should make.

maxpower671 10-02-2012 05:43 PM


Originally Posted by dartsteve
I think im going to stay from the dyno for awhile.
Just want a guestimate of what it should make.

- do your dyno guys have any real experience? :? real experience with alky?or are you teaching them?

-why not 1100-1200F on the pyro?

-why not .8xx on the Lambda?

-what do the plugs look like? burning any plating off the base?

cncmotorsports 10-03-2012 10:46 AM

Your EGT looks really low. How many RPM did you pull it to?

I also agree 38 degrees seems a bit much, but every motor is different.

dartsteve 10-11-2012 05:49 PM

6000rpm
Plugs looked clean

Headed to track tomorrow night i hope to have pics and slips
Plan is to do one pass then make some changes.

maxpower671 10-11-2012 07:47 PM


Originally Posted by dartsteve
6000rpm
Plugs looked clean

Headed to track tomorrow night i hope to have pics and slips
Plan is to do one pass then make some changes.

-set the timing
-check/set valve lash
-pull some fuel out slowly....watch your timeslips! :wink:
-have fun


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