ANOTHER What Do You Think Of This Dyno Chart Question

MODS:
85mmTB
MP Inlet
76 C&L (yellow tube)
3/4 Top
3" Intake (compression bent exhaust pipe - hey it was only $10.00!)
K&N flat panel (air silencer removed & additional holes drilled thru bottom of filter housing for added flow, foam seal added on outside of box bottom to keep engine heat out)
AL underdrive pulley set
AL jackshaft pulley
AL 5% overdrive pulley
BHJ balancer
IC fan
TBird gaskets
2.5 duel exhaust, high flow cats, 2.5 duel in/out magnaflow resonator, flowmaster deltaII mufflers (stock manifolds)
I have the 255 fuel pump but it is not installed, stock injectors, stock chip

I feel like an artists putting his work on display ... I know I could have spent money in other places and gotten a bigger bang for the buck. However, I think a solid foundation is in place for a cam, ported heads with valve job, headers, double IC, 42# injectors, and of course a chip which is next on the list.

you need a tune, your A/F ratio is all over the place. contact XR7Dave for one of his tunes, you wont be diappointed.

I know I need a tune ... this is my baseline

Regarding the A/F ratio, it is my understanding that the "up the pipe" wide bands used on these dynos is not as accurate as the pre-cat style ... also since there is some lag, is that the reason the A/F appears to drop from the beginning or once tuned properly will the A/F drop down to the desired ~11.6 ratio right from the start as opposed to not dropping below 12 until ~4250 rpms?

My biggest concern and another reason for getting this done was to make sure I was not running too lean ... which does not appear to be a problem

Also... check out the enlarged section of the chart and the areas I circled ... is this an indication of the knock sensors kicking in? power dropping off and then building back up?

I bet Dave could make that curve nice and smooth

I think you would make alot more power just by adding a ported blower like an MPII.

David

I have to agree about that need for a tune. Looks like it is running a little rich at times.

Shane

you need more fuel down low. I run 12 A/F only at peek torque after that its 12.5 all the way unless im tuning for better MPG. You can run these motors very lean up top, my car i run 13.7 A/F from around 4,700-red line and 28' timing. Some motors like a little more fuel then that but i like getting 25mpg and over 300 rwhp. These motos also like a lot of accelerator pump action the EEC tuner calls it manifold volume. As soon as you hit WOT your A/F should go very rich for a slit second then follow your target A/F of 12=12.5, your's is very lasy and im sure its pulling timing. I was to bussy looking at your A/F and I just looked at you HP and OMG most stock SCs autos i dynod are around 220hp your under by about 25hp. Get a tune

Name That Tune

There is an individual comming to the dyno Sat the 20th who is an SCT dealer. He will have his burner and is making his sevices available. The dyno guy said he was vary familiar with Fords. However, until I speak with this guy first hand and find out if he has done any SCs before I'm inclinded to seek out Mr. Dalke's services. If he is familar with the SC then obviously with the dyno being present that is the way to go. Nothing against anyone else it just seems having the dyno there to verify the burn and adjustments is how you want to do it.

I appreciate everyone comments very much and any hints or insights I could offer this individual in terms of how to interpret this data as it specifically pertains to our cars is very much appreciated.

Question on SC journey men's card test

BKB said:

you need more fuel down low. I run 12 A/F only at peek torque after that its 12.5 all the way unless im tuning for better MPG. You can run these motors very lean up top, my car i run 13.7 A/F from around 4,700-red line and 28' timing. Some motors like a little more fuel then that but i like getting 25mpg and over 300 rwhp. These motos also like a lot of accelerator pump action the EEC tuner calls it manifold volume. As soon as you hit WOT your A/F should go very rich for a slit second then follow your target A/F of 12=12.5, your's is very lasy and im sure its pulling timing. I was to bussy looking at your A/F and I just looked at you HP and OMG most stock SCs autos i dynod are around 220hp your under by about 25hp. Get a tune

Click to expand...

Extra Credit Test Question --- Describe the effects of correcting the A/F ratio on both torque and HP.

Answer - While there will be some increase in the HP this will not be nearly as significant as the improvement on the torque. The reason being the max HP occurs at higher rpms. At the higher rpm the A/F ratio is much closer to the "ideal" so the % increase will not be as significant. Max torque on the other hand occurs at a much lower rpm level. The A/F ratio is currently very lean preventing the torque from reaching its full potential and also causing a delay in it's build up. Correcting this situation should cause a significant improvement to the "seat of the pants" meter.

Graphical Analysis

Thought this might be of interest or at least generate some additional comments:

Looking at the vertical lines from the A/F curves and where they intersect with the power curves, you can definately see the effect the instability of the A/F has on these curves. There is a lag between the slope change on the A/F compared to the power curves but this seems to make sense to me.

Also, if you assume the instability is gone, I wonder if you can make some decent estimates on the potential torque improvements? For instance, assume the ramp up slope stays basically the same, and the ramp down slope does not change between 4000 and 5000 rpm where the A/F was decent/good. You can plot a new set of tangential lines for the "breakover curve" (for lack of a bettter descriptor). Doing this, it appears a max torque of 350 should be attainable.

Any thoughts?

heres my dyno chart look how smooth the A/F ratio is through the rpm range right around the 11.7 ratio. notice the hp and tq difference between run 1 and run 4 after tuning

MrBlvd said:

There is an individual comming to the dyno Sat the 20th who is an SCT dealer. He will have his burner and is making his sevices available. The dyno guy said he was vary familiar with Fords. However, until I speak with this guy first hand and find out if he has done any SCs before I'm inclinded to seek out Mr. Dalke's services. If he is familar with the SC then obviously with the dyno being present that is the way to go. Nothing against anyone else it just seems having the dyno there to verify the burn and adjustments is how you want to do it.

I appreciate everyone comments very much and any hints or insights I could offer this individual in terms of how to interpret this data as it specifically pertains to our cars is very much appreciated.

Click to expand...

If you don't mind, who is this individual doing the tuning? Reason I ask is I see you're in Virginia. If his name is Ed Clark, he's good. He did mine & Rick Z's a few weeks ago. XR7 Dave recommended him as well.