What do you guys think about these dyno numbers?

imcmantis

New Member
I have a dc4.

High Comp 9.6.1 b20z2 bottom block
with a b20 p8r head for the head.
Skunk 2 intake mani with 68mm portmatched tb
3 inch sri with velocity stack
dc sport headers 4-2-1
no cat straight 2.25 into a skunk 2 muffler

Im pushing 152 whp and 133 tq.

I feel like i lost alot of midrange and low end. Do you guys think this is average or what?
 

Muckman

Not a M0derator
Are you speaking about the very subtle dip in torque at 4.5k? Its pretty flat in my book.
I would have to examine the AFR and ignition output between 4 and 5.5k before blaming the parts.
Id like to know whats going on between 5.5 and 6k. Its like a weak VTEC engagement.
Makes me think the tune before this is soft.
You cant expect us to give a full analysis with just short part list and a cell phone pic of the dyno graph.
 

DaddyBuiltRacing

Resident Asshole
Just curious why you chose the p8r head, which is known to lower compression due to the 84mm combustion chambers
 


Muckman

Not a M0derator
I know very little about NON VTEC paper weights but I think the P8R head flows better than the P75? Still sucks tho.
 

DonJulio

Reppin' tha NW
DaddyBuiltRacing said:
Just curious why you chose the p8r head, which is known to lower compression due to the 84mm combustion chambers
Click to expand...
He has the 9.6 CPR b20z block. Which has a 84mm bore.

The p8r also has an 84mm bore.

I think you guys are confused with a b20 head on a LS block.

Muckman said:
from low to who cares
Click to expand...
The p75 as far as I know has the most aggressive exhaust cam found on an LS.
The p8r comes complete with a 2 layer headgasket, same for the b20z.

The p8r has better ports in the head than the LS.
The p8r also has 33mm valves, the largest on a non vtec b series vs the 31mm in the LS.

Hence that's why the b20z/jdm has a higher CPR.

130-140 ft lbs torque is easy achieved with just headers and an intake, which is more than what's rated at the flywheel.

The flywheel horsepower is only 143(jdm spec).
 

LoweredDC4

Jimmy
Regular b20s have Ls heads which means the combustion chamber smaller. B20 with p8r head has bigger combustion chamber make compression lower. B20 that come with p8r head usually have 9.2:1 CPR I think. Too tired to look google. Lol.
 

DonJulio

Reppin' tha NW
Just googled the b20b/z head. Not sure if it was clarifying the jdm or USDM b20b but they are both 81mm bores.

While the block and head gasket bores are 84mm.

That puts to me the conclusion the non vtec jdm high CPR b20 heads are the best upgrade for any non vtec B20, and LS if you want to work in a 84mm bore over the 81.

The only difference is head ports and larger valves, which is why the CPR is 9.6:1
 
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