• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-

When Do I Need To Retune?

  • Thread starter Thread starter 95SvtCobra347
  • Start date Start date Sep 25, 2017
9

95SvtCobra347

New Member
Sep 25, 2017
11
0
1
Sep 25, 2017
#1
  • Sep 25, 2017
  • #1
Hello,

I am new to the group and new to mustang. I have a 1995 cobra that I bought back in April. Everything was already done to the car and it had been dyno tuned. It has a 347 stroker with AFR heads, b303 cam, stock cobra gt40 intake, stock throttle body, aftermarket MAFS, BBK long tube headers, BBK off road x pipe and it had the factory cat back exhaust. The injectors are red. I think they are 30lb injectors by what I've read online but I'm 100% sure. I just changed to a flowmaster American thunder cat back which of course changed the mufflers and also increased the tail pipe diameter. The throttle response is way better and it pulls through the gears faster but I was wondering if the car was going to run lean and need to be returned with this change? I will take all the help and opinions that I can get from the knowledgeable people in this group. Thanks so much
 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
42,919
21,092
234
Box behind Walmart
Sep 25, 2017
#2
  • Sep 25, 2017
  • #2
95SvtCobra347 said:
347 stroker with AFR heads, b303 cam
Click to expand...


Have you driven it before? You're lucky to be alive.

95SvtCobra347 said:
It has a 347 stroker with AFR heads, b303 cam, stock cobra gt40 intake, stock throttle body, aftermarket MAFS,
Click to expand...

This combo has got to be choked choked choked.

Please post the dyno.

What AFR heads?
What MAF?
What injectors?
What fuel pump?
Who did the tune?
 
Reactions: 95SvtCobra347
9

95SvtCobra347

New Member
Sep 25, 2017
11
0
1
Sep 25, 2017
#3
  • Sep 25, 2017
  • #3
Noobz347 said:
Have you driven it before? You're lucky to be alive.



This combo has got to be choked choked choked.

Please post the dyno.

What AFR heads?
What MAF?
What injectors?
What fuel pump?
Who did the tune?
Click to expand...

Not sure about any of that stuff. I have dyno sheets they show 300hp and 333lbft. I know I have a lot to learn. I am willing to learn and listen with an open mind. This is also only my second sporty rear wheel drive car. I have always had trucks but before this I had a 1982 Oldsmobile cutlass with a mild small block Chevy.
 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
42,919
21,092
234
Box behind Walmart
Sep 25, 2017
#4
  • Sep 25, 2017
  • #4
Start taking pictures of everything in your engine bay and post them up alongside any dyno or build sheets.

You don't really need a tune to change mufflers but you probably sacrificed some performance by opening up the back of the exhaust system.

Google, "Tuned Exhaust System" and you will see what I mean.
 
Reactions: 95SvtCobra347
9

95SvtCobra347

New Member
Sep 25, 2017
11
0
1
Sep 25, 2017
#5
  • Sep 25, 2017
  • #5
I have no real build sheet I have a ton of receipts. I bought the car from the third owner. I called the phone number on one of the receipts and it was the original owner and he's the one who had all the motor work done.
 

Attachments

  • 0925171749a.webp
    89.9 KB · Views: 177
  • 0925171749.webp
    121.9 KB · Views: 188
  • 0925171736_HDR.webp
    391.6 KB · Views: 227
  • 0925171735_HDR.webp
    436.8 KB · Views: 199
  • 0925171733_HDR.webp
    454.2 KB · Views: 181
  • 0925171733a_HDR.webp
    388.8 KB · Views: 188
  • 0925171735.webp
    192.5 KB · Views: 163
  • 0925171734_HDR.webp
    456.5 KB · Views: 177
  • 0925171734.webp
    251.7 KB · Views: 169

Blown88GT

Founding Member
Nov 13, 1999
2,282
522
164
Palm Beach Gardens, FL
Sep 25, 2017
#6
  • Sep 25, 2017
  • #6
Red injectors are 30's. You don't need a re-tune just for exhaust changes. It has no affect on AFR.
 
Reactions: 95SvtCobra347
9

95SvtCobra347

New Member
Sep 25, 2017
11
0
1
Sep 25, 2017
#7
  • Sep 25, 2017
  • #7
Blown88GT said:
Red injectors are 30's. You don't need a re-tune just for exhaust changes. It has no affect on AFR.
Click to expand...

The car only pulls to about 4700 I was figuring that was because the throttle body and intake are starving the motor on the top end. What is your opinion? It seems like the same thing that happened when I had 305 heads on my 350 Chevy and it was starving because of the small intake runner size it fell off on the top end
 
9

95SvtCobra347

New Member
Sep 25, 2017
11
0
1
Sep 25, 2017
#8
  • Sep 25, 2017
  • #8
I'm sorry I forgot to thank you for your response. The reply and knowledge that it contained are greatly appreciated.
 

Dan02gt

mazing how much gas smell came from that tiny hole
20+ Year Stangneter
Mar 2, 2003
909
415
113
Greenville, NC
Sep 25, 2017
#9
  • Sep 25, 2017
  • #9
Your combo is definitely choked out, but doesn't really need a tune. You could probably pick up a good amount of power by sending that Cobra lower to Tmoss for a port job, installing a 70 or 75mm TB, making sure your fuel pump is up to the task, and installing a more modern cam.
 
Reactions: 95SvtCobra347
9

95SvtCobra347

New Member
Sep 25, 2017
11
0
1
Sep 25, 2017
#10
  • Sep 25, 2017
  • #10
Dan02gt said:
Your combo is definitely choked out, but doesn't really need a tune. You could probably pick up a good amount of power by sending that Cobra lower to Tmoss for a port job, installing a 70 or 75mm TB, making sure your fuel pump is up to the task, and installing a more modern cam.
Click to expand...

Would the porting and TB mods require a MAFS change or recalibration. I'm sure those mods will need tuned. What is the best way to tune this car. The car has some sort of chip with toggle is What the receipt says
 
You must log in or register to reply here.

Similar threads

D
Fuel pump upgrade
  • dkrupp79
  • Jul 7, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
4
Views
226
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jul 10, 2025
Scrapla347
Fox 329 HP low for a stroker?
  • Andresquintana.mma
  • Apr 15, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
23
Views
1K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Apr 19, 2025
Jarhead67
J
A
Discussion on mild budget build/ top end
  • Acesario
  • Feb 21, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
20
Views
645
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Feb 23, 2026
General karthief
SN95 Desktop 363 Engine Combination - Looking for input
  • WhiteCobra95
  • Sep 8, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
11
Views
1K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Oct 6, 2025
Habu135
M
Engine Unexplainable Exhaust Pop and Gurgle
  • Mrnissen122
  • Feb 14, 2026
  • Fox 5.0 Mustang Tech
Replies
12
Views
468
Fox 5.0 Mustang Tech Feb 18, 2026
Noobz347
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?