My Son's 347 at the Dyno sucked big time...

Wickd GT · 09-19-2009, 07:55 PM

Here is the combination:
347 stroker from CHP/probe, I bought this from a friend which had the cam in it listed below.
9.30:1 compression
TW Heads out of the Box
1.6 TFS roller rockers
Elgin cam
Duration @ .050 ..... 222 232
SAE Duration ......... 300 309
Lobe Spreed ..... ..... 112
Hydraulic Roller
Valve Lift ............ .509 .532
Cobra upper and lower port work
70mm throttle body
73mm mass air
24lbs injectors
190ltr fuel pump
adjustable Fuel regulator
BBK 1 5/8 shorties and BBK 2.5 x pipe with Dynomax Ultra flow mufflers exhaust
3.73 gears
10" PTC converter 3k stall and AOD with kevlar bands etc..

I made pulls to 5800-6000rpms.
No matter what I did to it it will not put more than 303hp and 349.98 ft lbs???? I will raise the fuel pressure and nothing, I will add timing, improved to 300hp and 339ft lbs. Add fuel and timing it went to to 297 and 292, put the fuel at 38psi and 16* and that was the sweet spot, but only 303hp and 349.98 ft lbs.

Either the stock computer, which is a factory one for automatic, is fighting what I do or the cam is wrong for the combination. Or the damn dyno is not accurate. The car feels strong on the street, but that don't mean anything. I guess the track will tell. Any ideas here, is it the computer fighting this tune or the cam is not enough for the heads. What you guys think. A/F ratio was alway 13.5 no matter if I raised it or lower it???? I'm so ****ing piss that I can't even see straight:

Edgar

QWKSNKE · 09-19-2009, 09:14 PM

What did the graph look like? When did the curve start nosing over?

If it started losing power early (5000 rpm or so), then I still say the intake is not enough to handle the heads and cubic displacement. Also, in my opinion the MAF and intake piping are to small. Definitly will be if you ever swap the intake.

QWKSNKE · 09-19-2009, 09:19 PM

Forgot to ask when we were on the phone today, what kind of power were you expecting? The torque is there. The auto could have something to do with what the dyno says to. That auto is probably robbing a good 25 rwhp or more compared to the same combo with a 5 speed.

Wickd GT · 09-19-2009, 09:31 PM

Here is the graph:

QWKSNKE · 09-19-2009, 09:56 PM

I suspect with a EEC tune you could find another 10rwhp (Typically this is what we found on all of my n/a combos when we changed the tune in the computer). I still say you can find another 10-15 throughout the upper rpm range with a intake swap.

But like you said, the track will be the true test. From a dyno perspective my last combo with the Anderson cam dyno'd less than the same combo with a 'B' cam but the Anderson cam combo ran nearly a full second quicker at the track. Probably would have been a over a second quicker if I could have got the damn thing to hook off the line without breaking tranny's

coupe · 09-20-2009, 05:53 PM

I'm sure the Cobra isn't helping at 6000 RPM, but that combo should make huge midrange and torque... which IIRC, was actually down from the previous 302. The air has been bad lately (humid, warm, etc) so consider that too.

I think a tune is in order, to let the CPU know that it is a larger motor and to "tweak" some things... I think the next steps will be a larger cam (for the money, an X303, Z303, or Trick Flow stage 2 would be really nice) and ...yes... a different intake possibly like a RPMII or Systemax. I would also consider a DOWNS-Ford breadbox intake... it would sit right on that cobra lower and really wake up the power peak.

See what she does at trackday first tho. Might be surprised...lets hope it's cool and dry air!

nxcoupe · 09-25-2009, 01:46 PM

Is the cobra box stock or ported?

Dale McPeters · 09-25-2009, 02:07 PM

Edgar,

Lee & Matt are correct. You need a tune for the EEC. It still thinks it is running a stock 302 if you have not had a chip burned for it yet. The car should be putting down around 350ish.

The little baby 306 that I rebuilt that was in the '93 cobra made more than that...

coupe · 09-25-2009, 02:24 PM

I believe Edgar found someone locally who could access the computer and flash him a chip (maybe SCT?)...

I'm anxious to hear the results!

Dale McPeters · 09-25-2009, 03:16 PM

Quote:

Originally Posted by coupe

I believe Edgar found someone locally who could access the computer and flash him a chip (maybe SCT?)...

I'm anxious to hear the results!

That is good as that car is leaving a lot on the table.

Yep it is probably SCT.

09-19-2009, 07:55 PM	#1
Wickd GT Friends Join Date: Dec 2004 Posts: 1,645	My Son's 347 at the Dyno sucked big time... Here is the combination: 347 stroker from CHP/probe, I bought this from a friend which had the cam in it listed below. 9.30:1 compression TW Heads out of the Box 1.6 TFS roller rockers Elgin cam Duration @ .050 ..... 222 232 SAE Duration ......... 300 309 Lobe Spreed ..... ..... 112 Hydraulic Roller Valve Lift ............ .509 .532 Cobra upper and lower port work 70mm throttle body 73mm mass air 24lbs injectors 190ltr fuel pump adjustable Fuel regulator BBK 1 5/8 shorties and BBK 2.5 x pipe with Dynomax Ultra flow mufflers exhaust 3.73 gears 10" PTC converter 3k stall and AOD with kevlar bands etc.. I made pulls to 5800-6000rpms. No matter what I did to it it will not put more than 303hp and 349.98 ft lbs???? I will raise the fuel pressure and nothing, I will add timing, improved to 300hp and 339ft lbs. Add fuel and timing it went to to 297 and 292, put the fuel at 38psi and 16* and that was the sweet spot, but only 303hp and 349.98 ft lbs. Either the stock computer, which is a factory one for automatic, is fighting what I do or the cam is wrong for the combination. Or the damn dyno is not accurate. The car feels strong on the street, but that don't mean anything. I guess the track will tell. Any ideas here, is it the computer fighting this tune or the cam is not enough for the heads. What you guys think. A/F ratio was alway 13.5 no matter if I raised it or lower it???? I'm so ****ing piss that I can't even see straight: Edgar

09-19-2009, 09:14 PM	#2
QWKSNKE 3v's are slow Join Date: Dec 2004 Location: Here and There Posts: 17,152	What did the graph look like? When did the curve start nosing over? If it started losing power early (5000 rpm or so), then I still say the intake is not enough to handle the heads and cubic displacement. Also, in my opinion the MAF and intake piping are to small. Definitly will be if you ever swap the intake. __________________ 2009 Porsche Carrera S 2008 ///AMG C63.. Eurocharge Tune. RIP 2019 AMG GLC43..wife's 03 F250 SD.. Edge Evo, AFE Stage 1 CAI 08 GT. JBA axle back, FRPP springs, FRPP swaybars.. daughter's 01 Cobra vert... wife's I need a new toy

09-19-2009, 09:19 PM	#3
QWKSNKE 3v's are slow Join Date: Dec 2004 Location: Here and There Posts: 17,152	Forgot to ask when we were on the phone today, what kind of power were you expecting? The torque is there. The auto could have something to do with what the dyno says to. That auto is probably robbing a good 25 rwhp or more compared to the same combo with a 5 speed. __________________ 2009 Porsche Carrera S 2008 ///AMG C63.. Eurocharge Tune. RIP 2019 AMG GLC43..wife's 03 F250 SD.. Edge Evo, AFE Stage 1 CAI 08 GT. JBA axle back, FRPP springs, FRPP swaybars.. daughter's 01 Cobra vert... wife's I need a new toy

09-19-2009, 09:56 PM	#5
QWKSNKE 3v's are slow Join Date: Dec 2004 Location: Here and There Posts: 17,152	I suspect with a EEC tune you could find another 10rwhp (Typically this is what we found on all of my n/a combos when we changed the tune in the computer). I still say you can find another 10-15 throughout the upper rpm range with a intake swap. But like you said, the track will be the true test. From a dyno perspective my last combo with the Anderson cam dyno'd less than the same combo with a 'B' cam but the Anderson cam combo ran nearly a full second quicker at the track. Probably would have been a over a second quicker if I could have got the damn thing to hook off the line without breaking tranny's __________________ 2009 Porsche Carrera S 2008 ///AMG C63.. Eurocharge Tune. RIP 2019 AMG GLC43..wife's 03 F250 SD.. Edge Evo, AFE Stage 1 CAI 08 GT. JBA axle back, FRPP springs, FRPP swaybars.. daughter's 01 Cobra vert... wife's I need a new toy

09-20-2009, 05:53 PM	#6
coupe Super Moderator Join Date: Dec 2004 Posts: 6,313	I'm sure the Cobra isn't helping at 6000 RPM, but that combo should make huge midrange and torque... which IIRC, was actually down from the previous 302. The air has been bad lately (humid, warm, etc) so consider that too. I think a tune is in order, to let the CPU know that it is a larger motor and to "tweak" some things... I think the next steps will be a larger cam (for the money, an X303, Z303, or Trick Flow stage 2 would be really nice) and ...yes... a different intake possibly like a RPMII or Systemax. I would also consider a DOWNS-Ford breadbox intake... it would sit right on that cobra lower and really wake up the power peak. See what she does at trackday first tho. Might be surprised...lets hope it's cool and dry air! __________________ " If you can't explain it simply, you don't understand it well enough. " - Albert Einstein

09-25-2009, 01:46 PM	#7
nxcoupe Senior Member Join Date: Dec 2005 Location: Somewhere, Afghanistan Posts: 122	Is the cobra box stock or ported? __________________ Michael 92 coupe R/S 8

09-25-2009, 02:07 PM	#8
Dale McPeters 5.0 Block/Walnut Cracker Join Date: May 2005 Location: Working.... Posts: 2,409	Edgar, Lee & Matt are correct. You need a tune for the EEC. It still thinks it is running a stock 302 if you have not had a chip burned for it yet. The car should be putting down around 350ish. The little baby 306 that I rebuilt that was in the '93 cobra made more than that... __________________ '14 Dodge Challenger SRT8 392 6-speed

09-25-2009, 02:24 PM	#9
coupe Super Moderator Join Date: Dec 2004 Posts: 6,313	I believe Edgar found someone locally who could access the computer and flash him a chip (maybe SCT?)... I'm anxious to hear the results! __________________ " If you can't explain it simply, you don't understand it well enough. " - Albert Einstein