First Dyno Experience, HORRIBLE!!!

mojosvt · 03-19-2006, 08:30 PM

Well, It was like christmas, I was so excited that I could not sleep last night. Drive to the dyno shop with a smile ear to ear. Swap out the stock pulley for a 2.76, along with the billetflow 4 piece set. No Problem.... Get her up on the dyno, start doing some little check, everything perfect. Start doing some small pulls to 3000 rpm, the a/f ratio, is all over the map. But everything else is near perfect, front os sensors, fuel pressure, maf flows, the power curve was flawless, but still the a/f is up and down and up jumping all over the place between 14 and 11. so we assume that there must be an exhaust leak, and not actually that lean, because the power was perfect. I don't think you could put down 488 rwt @3000rpm with an engine that lean. So we swap out the rear O2 sensor, and swap out the tailpipe siffer and hook it up on the o2's place. Almost exact same line..all over the place. double check and make sure the dyno is ok, put another cobra up, perfect 11.3 a/f line. so wer recheck where the x-pipe meets the headers, no leaks... WTF

!!!!!! So i ended up having to leave without any tuning, just running the Xcal2 tune, with a supposed a/f bouncing between 11 and 14. Any suggestions would be great.Thanks guys, Mike

Dave B. · 03-19-2006, 09:09 PM

Ok the RWTQ was 488 but what was the RWHP ???

mojosvt · 03-19-2006, 09:51 PM

Sorry, I put down 466 rwhp, and like I said, perfect curve.

Dave B. · 03-19-2006, 09:56 PM

Ok so you got 466 RWHP and 488 RWTQ ??? is that correct?
if so, thats about right for a 2,76 pulley, before my stage 4 i had 468 RWHP and 485 RWTQ so what you got would be right on the money, do you have any headers, or a differant heat exchanger ??

**cobrabitn** · 03-19-2006, 11:13 PM

You guys are killing me! Do you know what it is like to read all of this knowing you have Mystichrome in the garage just waiting to be pumped up another 100 rwhp? Sheeshh... I'm choking here!

Mike, Come to Charlotte!

Wish we could have got the rest of the Buckeyes to come to Autofair on Saturday and do the AX on Sunday!

03slidewayzSVT · 03-19-2006, 11:21 PM

Tony, Get out of the rocker and get the phone and start ordering some parts hehehehe

Torrey could you give Tony here a little help here???? sound like someone has tooooo

**cobrabitn** · 03-19-2006, 11:26 PM

I already have a 2.80 pulley and a pulley puller that was given to me. I thought I would go with just a lower pulley for now, a 4lb type? What sort of hp increase will I get from that? Do I really need to get different idlers with that set up?

P.S. I just spent 6.5 hours doing the club's financial report, I don't have time to make phone calls...

03slidewayzSVT · 03-19-2006, 11:36 PM

from what? 2.8 pulley and 4lb lower or just the 2.8??? and nothing else???

**cobrabitn** · 03-19-2006, 11:39 PM

Either or?? With a 2.8 only or with a 4 lb lower only...

spincobra03 · 03-19-2006, 11:42 PM

cobrabitn I just changed to a 6lb lower and you will need an alternator pulley with the lower changed, as for hp increase with the lower and upper im not sure but I would assume it would have to be retuned. To give you an idea I was 385 rwhp and 405 rwtq and after the 6lb lower I was 465 rwph and 513 rwtq. From what I have been told the lower should give you bigger tourqe increases, slighty more than hp. As I said I dont know about both upper and lower combo, when I spoke to rob at pro dyno he just said it was easier to just change the lower rather than change all the idlers and upper because by just changing the lower I would see the same hp but much more tourqe by going with the lower.

**cobrabitn** · 03-20-2006, 12:30 AM

Do I need to change the alternator pulley with a 4lb lower or will I have charging problems if I don't? If I can get 475 rwhp with a tune and a 4lb lower then I'll be going that route for now till my hp hunger strikes again!

03slidewayzSVT · 03-20-2006, 12:40 AM

I believe anything more than a 2lb lower you need and alt. pulley. I think there only $25-30 dollars. I think 475rwhp without CAI and exhaust is not happening...

**cobrabitn** · 03-20-2006, 05:19 AM

I have a JLT and Magnaflows!

mojosvt · 03-20-2006, 08:44 AM

Yeah, stock headers, and stock HE. I personally went over every single bolt on the x-pipe and the cat back, there are no leaks. Have set up an appt with dan on the 7th of april. Hopefully can get her running right before the 411. Any other suggestions would be great, thanks

Ram77mus · 03-20-2006, 01:30 PM

You will need a alt. pulley with anymore then a 2lbs lower. A 2.8 upper work very close to a 4lbs lower. People don't like to spend the money on the lowers because they are $300+, but if you add up all the parts to put a 2.8 on (2.8 =$65+, idlers $150-$250) you end up spending the same amount. SPINCOBRA03 seemed to have very good luck with just a 6lbs lower

03-19-2006, 08:30 PM	#1
mojosvt SCMC Member Join Date: Mar 2005 Location: Columbus, Oh Posts: 614	First Dyno Experience, HORRIBLE!!! Well, It was like christmas, I was so excited that I could not sleep last night. Drive to the dyno shop with a smile ear to ear. Swap out the stock pulley for a 2.76, along with the billetflow 4 piece set. No Problem.... Get her up on the dyno, start doing some little check, everything perfect. Start doing some small pulls to 3000 rpm, the a/f ratio, is all over the map. But everything else is near perfect, front os sensors, fuel pressure, maf flows, the power curve was flawless, but still the a/f is up and down and up jumping all over the place between 14 and 11. so we assume that there must be an exhaust leak, and not actually that lean, because the power was perfect. I don't think you could put down 488 rwt @3000rpm with an engine that lean. So we swap out the rear O2 sensor, and swap out the tailpipe siffer and hook it up on the o2's place. Almost exact same line..all over the place. double check and make sure the dyno is ok, put another cobra up, perfect 11.3 a/f line. so wer recheck where the x-pipe meets the headers, no leaks... WTF !!!!!! So i ended up having to leave without any tuning, just running the Xcal2 tune, with a supposed a/f bouncing between 11 and 14. Any suggestions would be great.Thanks guys, Mike __________________ 1997 Kenny Brown Cobra Convertible! 1996 Mystic Cobra Coupe, Griggs and MM track ready SOLD 2003 Mineral Gray Cobra convertible #466, 1 of 152 SOLD

03-19-2006, 09:09 PM	#2
Dave B. Registered User Join Date: Dec 2003 Location: Florida Posts: 479	Ok the RWTQ was 488 but what was the RWHP ??? __________________ 03 Cobra 10th Anniversary Red Stiegermeier Stage 4 ported Eaton 511.9 RWHP 467.7 RWTQ 2,76 Billetflow SC pulley Billetflow Aux-idler all billetflow idler pulleys Accufab single blade MAC cold air BBK Ceramic LT headers X-pipe Magnaflow exhaust Gordsford heat exchanger PST Carbon fiber drive shaft lowered 1.5 inches 18 X 9's AFS running Toyos 275/35/18's front 18 X 10.5's AFS running Toyos 295/35/18's rear Cobra "R" rear wing Cobra "R" hood 4:10 gears Pedator tuned Pro short shifter Hurst "T" handle Promotion Clutch Quad AEM widband gauge Boost & fuel Press gauges drilled & slotted rotors

03-19-2006, 09:51 PM	#3
mojosvt SCMC Member Join Date: Mar 2005 Location: Columbus, Oh Posts: 614	Sorry, I put down 466 rwhp, and like I said, perfect curve. __________________ 1997 Kenny Brown Cobra Convertible! 1996 Mystic Cobra Coupe, Griggs and MM track ready SOLD 2003 Mineral Gray Cobra convertible #466, 1 of 152 SOLD

03-19-2006, 09:56 PM	#4
Dave B. Registered User Join Date: Dec 2003 Location: Florida Posts: 479	Ok so you got 466 RWHP and 488 RWTQ ??? is that correct? if so, thats about right for a 2,76 pulley, before my stage 4 i had 468 RWHP and 485 RWTQ so what you got would be right on the money, do you have any headers, or a differant heat exchanger ?? __________________ 03 Cobra 10th Anniversary Red Stiegermeier Stage 4 ported Eaton 511.9 RWHP 467.7 RWTQ 2,76 Billetflow SC pulley Billetflow Aux-idler all billetflow idler pulleys Accufab single blade MAC cold air BBK Ceramic LT headers X-pipe Magnaflow exhaust Gordsford heat exchanger PST Carbon fiber drive shaft lowered 1.5 inches 18 X 9's AFS running Toyos 275/35/18's front 18 X 10.5's AFS running Toyos 295/35/18's rear Cobra "R" rear wing Cobra "R" hood 4:10 gears Pedator tuned Pro short shifter Hurst "T" handle Promotion Clutch Quad AEM widband gauge Boost & fuel Press gauges drilled & slotted rotors

03-19-2006, 11:13 PM	#5
cobrabitn Dr Jekyll on the street, Mr Hyde on the track Join Date: Jun 2001 Location: Rock Hill SC Posts: 14,649	You guys are killing me! Do you know what it is like to read all of this knowing you have Mystichrome in the garage just waiting to be pumped up another 100 rwhp? Sheeshh... I'm choking here! Mike, Come to Charlotte! Wish we could have got the rest of the Buckeyes to come to Autofair on Saturday and do the AX on Sunday! __________________ Cobrabitn 2016 Ruby Red Metallic with Caribou accent F-350 Crew Cab Stump Puller! 6.7 Diesel Automatic with Chrome Package, Off Road Package, 3.55 Locking axles, and Ultimate Lariat Interior Trim Package! 2017 Shelby GT350 Coupe - track car! Mods: JLT True Cold Air oil catch can 2009 Vista Blue Shelby GT 500 Coupe - Garage Queen Tinted Windows JLT True Cold Air Kit Pro-Dyno Tune 526 rwhp - 511 rwtq 1994 Rio Red Indy Pace Car #22 "Runabout" Snake in the grill MGW shift knob 1996 SVT Cobra Wheels 1969 New Lime Mustang Mach 1 Sportsroof - Second owner - bone stock with shaker. One SVT Cobra, one Shelby GT500, one 69 mach 1, and a Shelby GT350 is better than nothing! Custom Data Plates for your Mustang or Ford! Buy "Cool Merchandise" at Data Plates Plus www.dataplatesplus.com See my MSR Video here!

03-19-2006, 11:21 PM	#6
03slidewayzSVT Registered User Join Date: Oct 2005 Location: Kannapolis, NC Posts: 475	Tony, Get out of the rocker and get the phone and start ordering some parts hehehehe Torrey could you give Tony here a little help here???? sound like someone has tooooo __________________

03-19-2006, 11:26 PM	#7
cobrabitn Dr Jekyll on the street, Mr Hyde on the track Join Date: Jun 2001 Location: Rock Hill SC Posts: 14,649	I already have a 2.80 pulley and a pulley puller that was given to me. I thought I would go with just a lower pulley for now, a 4lb type? What sort of hp increase will I get from that? Do I really need to get different idlers with that set up? P.S. I just spent 6.5 hours doing the club's financial report, I don't have time to make phone calls... __________________ Cobrabitn 2016 Ruby Red Metallic with Caribou accent F-350 Crew Cab Stump Puller! 6.7 Diesel Automatic with Chrome Package, Off Road Package, 3.55 Locking axles, and Ultimate Lariat Interior Trim Package! 2017 Shelby GT350 Coupe - track car! Mods: JLT True Cold Air oil catch can 2009 Vista Blue Shelby GT 500 Coupe - Garage Queen Tinted Windows JLT True Cold Air Kit Pro-Dyno Tune 526 rwhp - 511 rwtq 1994 Rio Red Indy Pace Car #22 "Runabout" Snake in the grill MGW shift knob 1996 SVT Cobra Wheels 1969 New Lime Mustang Mach 1 Sportsroof - Second owner - bone stock with shaker. One SVT Cobra, one Shelby GT500, one 69 mach 1, and a Shelby GT350 is better than nothing! Custom Data Plates for your Mustang or Ford! Buy "Cool Merchandise" at Data Plates Plus www.dataplatesplus.com See my MSR Video here!

03-19-2006, 11:36 PM	#8
03slidewayzSVT Registered User Join Date: Oct 2005 Location: Kannapolis, NC Posts: 475	from what? 2.8 pulley and 4lb lower or just the 2.8??? and nothing else??? __________________

03-19-2006, 11:39 PM	#9
cobrabitn Dr Jekyll on the street, Mr Hyde on the track Join Date: Jun 2001 Location: Rock Hill SC Posts: 14,649	Either or?? With a 2.8 only or with a 4 lb lower only... __________________ Cobrabitn 2016 Ruby Red Metallic with Caribou accent F-350 Crew Cab Stump Puller! 6.7 Diesel Automatic with Chrome Package, Off Road Package, 3.55 Locking axles, and Ultimate Lariat Interior Trim Package! 2017 Shelby GT350 Coupe - track car! Mods: JLT True Cold Air oil catch can 2009 Vista Blue Shelby GT 500 Coupe - Garage Queen Tinted Windows JLT True Cold Air Kit Pro-Dyno Tune 526 rwhp - 511 rwtq 1994 Rio Red Indy Pace Car #22 "Runabout" Snake in the grill MGW shift knob 1996 SVT Cobra Wheels 1969 New Lime Mustang Mach 1 Sportsroof - Second owner - bone stock with shaker. One SVT Cobra, one Shelby GT500, one 69 mach 1, and a Shelby GT350 is better than nothing! Custom Data Plates for your Mustang or Ford! Buy "Cool Merchandise" at Data Plates Plus www.dataplatesplus.com See my MSR Video here!

03-19-2006, 11:42 PM	#10
spincobra03 Registered User Join Date: Dec 2005 Posts: 129	cobrabitn I just changed to a 6lb lower and you will need an alternator pulley with the lower changed, as for hp increase with the lower and upper im not sure but I would assume it would have to be retuned. To give you an idea I was 385 rwhp and 405 rwtq and after the 6lb lower I was 465 rwph and 513 rwtq. From what I have been told the lower should give you bigger tourqe increases, slighty more than hp. As I said I dont know about both upper and lower combo, when I spoke to rob at pro dyno he just said it was easier to just change the lower rather than change all the idlers and upper because by just changing the lower I would see the same hp but much more tourqe by going with the lower.

03-20-2006, 12:30 AM	#11
cobrabitn Dr Jekyll on the street, Mr Hyde on the track Join Date: Jun 2001 Location: Rock Hill SC Posts: 14,649	Do I need to change the alternator pulley with a 4lb lower or will I have charging problems if I don't? If I can get 475 rwhp with a tune and a 4lb lower then I'll be going that route for now till my hp hunger strikes again! __________________ Cobrabitn 2016 Ruby Red Metallic with Caribou accent F-350 Crew Cab Stump Puller! 6.7 Diesel Automatic with Chrome Package, Off Road Package, 3.55 Locking axles, and Ultimate Lariat Interior Trim Package! 2017 Shelby GT350 Coupe - track car! Mods: JLT True Cold Air oil catch can 2009 Vista Blue Shelby GT 500 Coupe - Garage Queen Tinted Windows JLT True Cold Air Kit Pro-Dyno Tune 526 rwhp - 511 rwtq 1994 Rio Red Indy Pace Car #22 "Runabout" Snake in the grill MGW shift knob 1996 SVT Cobra Wheels 1969 New Lime Mustang Mach 1 Sportsroof - Second owner - bone stock with shaker. One SVT Cobra, one Shelby GT500, one 69 mach 1, and a Shelby GT350 is better than nothing! Custom Data Plates for your Mustang or Ford! Buy "Cool Merchandise" at Data Plates Plus www.dataplatesplus.com See my MSR Video here!

03-20-2006, 12:40 AM	#12
03slidewayzSVT Registered User Join Date: Oct 2005 Location: Kannapolis, NC Posts: 475	I believe anything more than a 2lb lower you need and alt. pulley. I think there only $25-30 dollars. I think 475rwhp without CAI and exhaust is not happening... __________________

03-20-2006, 05:19 AM	#13
cobrabitn Dr Jekyll on the street, Mr Hyde on the track Join Date: Jun 2001 Location: Rock Hill SC Posts: 14,649	I have a JLT and Magnaflows! __________________ Cobrabitn 2016 Ruby Red Metallic with Caribou accent F-350 Crew Cab Stump Puller! 6.7 Diesel Automatic with Chrome Package, Off Road Package, 3.55 Locking axles, and Ultimate Lariat Interior Trim Package! 2017 Shelby GT350 Coupe - track car! Mods: JLT True Cold Air oil catch can 2009 Vista Blue Shelby GT 500 Coupe - Garage Queen Tinted Windows JLT True Cold Air Kit Pro-Dyno Tune 526 rwhp - 511 rwtq 1994 Rio Red Indy Pace Car #22 "Runabout" Snake in the grill MGW shift knob 1996 SVT Cobra Wheels 1969 New Lime Mustang Mach 1 Sportsroof - Second owner - bone stock with shaker. One SVT Cobra, one Shelby GT500, one 69 mach 1, and a Shelby GT350 is better than nothing! Custom Data Plates for your Mustang or Ford! Buy "Cool Merchandise" at Data Plates Plus www.dataplatesplus.com See my MSR Video here!

03-20-2006, 08:44 AM	#14
mojosvt SCMC Member Join Date: Mar 2005 Location: Columbus, Oh Posts: 614	Yeah, stock headers, and stock HE. I personally went over every single bolt on the x-pipe and the cat back, there are no leaks. Have set up an appt with dan on the 7th of april. Hopefully can get her running right before the 411. Any other suggestions would be great, thanks __________________ 1997 Kenny Brown Cobra Convertible! 1996 Mystic Cobra Coupe, Griggs and MM track ready SOLD 2003 Mineral Gray Cobra convertible #466, 1 of 152 SOLD

03-20-2006, 01:30 PM	#15
Ram77mus Registered User Join Date: Feb 2006 Location: SC Posts: 168	You will need a alt. pulley with anymore then a 2lbs lower. A 2.8 upper work very close to a 4lbs lower. People don't like to spend the money on the lowers because they are $300+, but if you add up all the parts to put a 2.8 on (2.8 =$65+, idlers $150-$250) you end up spending the same amount. SPINCOBRA03 seemed to have very good luck with just a 6lbs lower __________________ SCT Level 4 Trained Tuner with over 12 years of experience in the automotive performance industries. Throttle, Bottle or Boost - First to the Finish Line "WINS" www.powercurvemotorsports.com

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