Problems after headers and dyno
Thread Starter
Racer
Joined: Feb 2016
Posts: 284
Likes: 105
Problems after headers and dyno
Just had 1 7/8 Ts headers and x pipe installed
Then got it tuned with hp tuner
After had misfire in 3th cylinder, new plug fixed that
Then mustang dyno
After dyno got codes P0700 and U0073 Car wouldn’t shift out of 4th gear. Turned it off, waited a few minutes, restarted car. Shifts fix now but codes still on. Is this just bc of the dyno and back wheels going 120 mph when front wasn’t moving?
Also what do base c7’s pull stock? Figured I’d get more from headers than I did.
Thanks
Then got it tuned with hp tuner
After had misfire in 3th cylinder, new plug fixed that
Then mustang dyno
After dyno got codes P0700 and U0073 Car wouldn’t shift out of 4th gear. Turned it off, waited a few minutes, restarted car. Shifts fix now but codes still on. Is this just bc of the dyno and back wheels going 120 mph when front wasn’t moving?
Also what do base c7’s pull stock? Figured I’d get more from headers than I did.
Thanks
Le Mans Master
Joined: Oct 2014
Posts: 8,673
Likes: 2,728
From: Atlanta GA
Mustang Dynos depending on how they are setup will almost always read lower than a Dyno Jet
A dyno should be a tool just to measure your gain or loss and not the determining factor on your HP number . What was your baseline and what was your numbers after install . It's a known fact that headers and a tune will give you 30 to 40 hp gain
It does not matter what the dyno number is becaue the ultimate measure is at the Track ....
Dave
A dyno should be a tool just to measure your gain or loss and not the determining factor on your HP number . What was your baseline and what was your numbers after install . It's a known fact that headers and a tune will give you 30 to 40 hp gain
It does not matter what the dyno number is becaue the ultimate measure is at the Track ....
Dave
Last edited by Dcasole; Mar 15, 2020 at 06:48 PM.
Le Mans Master
Joined: Oct 2014
Posts: 8,673
Likes: 2,728
From: Atlanta GA
The 700 codes are generic trans codes where the TCM is asking the ECM to turn on the CEL . To get the TCM code you need a scanner that will access the TCM . I have the GDS2 software and a GM MDI, I also got a 700 code and it was caused by a speed difference between the main shaft and the output shaft that the trans did not like , I was getting shift flair between 1st and 2and gear shift
even after fixing the issues I still have both codes in history
So i am assuming that your trans just did not like the Dyno since its shifting fine now
Dave
even after fixing the issues I still have both codes in history
So i am assuming that your trans just did not like the Dyno since its shifting fine now
Dave
Last edited by Dcasole; Mar 15, 2020 at 06:46 PM.
Thread Starter
Racer
Joined: Feb 2016
Posts: 284
Likes: 105
The 700 codes are generic trans codes where the TCM is asking the ECM to turn on the CEL . To get the TCM code you need a scanner that will access the TCM . I have the GDS2 software and a GM MDI, I also got a 700 code and it was caused by a speed difference between the main shaft and the output shaft that the trans did not like , I was getting shift flair between 1st and 2and gear shift
even after fixing the issues I still have both codes in history
So i am assuming that your trans just did not like the Dyno since its shifting fine now
Dave
even after fixing the issues I still have both codes in history
So i am assuming that your trans just did not like the Dyno since its shifting fine now
Dave
i’ll play with it and let you know.
Thread Starter
Racer
Joined: Feb 2016
Posts: 284
Likes: 105
Mustang Dynos depending on how they are setup will almost always read lower than a Dyno Jet
A dyno should be a tool just to measure your gain or loss and not the determining factor on your HP number . What was your baseline and what was your numbers after install . It's a known fact that headers and a tune will give you 30 to 40 hp gain
It does not matter what the dyno number is becaue the ultimate measure is at the Track ....
Dave
A dyno should be a tool just to measure your gain or loss and not the determining factor on your HP number . What was your baseline and what was your numbers after install . It's a known fact that headers and a tune will give you 30 to 40 hp gain
It does not matter what the dyno number is becaue the ultimate measure is at the Track ....
Dave
Le Mans Master
Joined: Oct 2014
Posts: 8,673
Likes: 2,728
From: Atlanta GA
An exact number is hard to put a finger on because it all depends on the weather that day , the type headers , the operator and the dyno but most guys using a dynojet are reporting anywhere from 440 to 460 after adding headers and a good tune .
Remember a dyno operator can make that thing report any number he wants
Dave
Remember a dyno operator can make that thing report any number he wants
Dave
Former Vendor
Joined: Feb 2012
Posts: 26,512
Likes: 351
From: ST. CHARLES IL
This is why we always give free baseline tests before we mod a car. Look at the gains not the end number. Our dyno reads a bit light compared to others and we get C7s ranging from 370-400rwhp. So headers and a tune usually end up around 405-440rwhp.
Any dyno operator should make sure the traction control and stability control are off before the pull is made. The dyno tends to freak newer cars out if everything isn't turned off.
Any dyno operator should make sure the traction control and stability control are off before the pull is made. The dyno tends to freak newer cars out if everything isn't turned off.
Safety Car
Joined: Jul 2009
Posts: 3,755
Likes: 190
From: Baton Rouge LA
St. Jude Donor '14, '16
This is why we always give free baseline tests before we mod a car. Look at the gains not the end number. Our dyno reads a bit light compared to others and we get C7s ranging from 370-400rwhp. So headers and a tune usually end up around 405-440rwhp.
Any dyno operator should make sure the traction control and stability control are off before the pull is made. The dyno tends to freak newer cars out if everything isn't turned off.
Any dyno operator should make sure the traction control and stability control are off before the pull is made. The dyno tends to freak newer cars out if everything isn't turned off.
OP, U codes like that in my experience usually stem from an improper keycycle after a tune revision was put in.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski