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Engine 2003 Mach 1 Automatic Upgrades assistance

  • Thread starter Thread starter SJK1417M1AT
  • Start date Start date Sep 25, 2025
S

SJK1417M1AT

New Member
Sep 25, 2025
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Twinsburg, Ohio
Sep 25, 2025
#1
  • Sep 25, 2025
  • #1
Help people if stangnet. I just purchased a 2003 Mach 1. It was a dream car in high school and always loved the look since day 1. It is an automatic but due to severe back pain I cannot drive a manual. I have attached some paperwork the dealership had. Unfortunately previous owner passed away so no way of contacting.

This was strictly a vanity purchase because I had been searching for a while.

This is what I know:
a. Eagle Stage 6 forged rods
b. iProCharger supercharger and Stage II intercooler upgrade
c. magnaflow exhaust

I plan to take it to the shop but need some help.

I live in the Cleveland/Akron/Twinsburg Ohio area are there any recommendations for shops?

Second I would like to get the classic chop and was hoping to upgrade the cams and add headers shorty vs long? And I would like to upgrade the suspension plus h pipe. Also any recommendations on stabilizing the car as far as brand front and rear? As far as suspension I would prefer something a bit more forgiving than stiff.


Are there any other upgrades I would need to do to make this the final build

Any recommendations on brands and def don’t touch this brand vs others.

I tried reading and am getting a bit overwhelmed with the amount of information is separate locations so thought I would reach out here.

I do understand this may not be the right place to ask. Also I work a job that at times I have zero chance at doing any research on my own for weeks on ends since I pretty much eat sleep and drive to work and work. I would really appreciate any help.
 

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S

SJK1417M1AT

New Member
Sep 25, 2025
2
0
1
Twinsburg, Ohio
Sep 25, 2025
#2
  • Sep 25, 2025
  • #2
Also forgot to add tot the post how much power do you think this thing is making?
 
0

01SVTvertt

New Member
Dec 21, 2025
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1
USA
Dec 21, 2025
#3
  • Dec 21, 2025
  • #3
My guess through an auto with that tiny fuel pump is somewhere around 400. The auto will hurt you due to the parasitic losses associated with it. You could be making WAY more with forged internals but would need a twin pump fuel hat and better pumps such as two GT supercar pumps and then a retune.

I make 450 rwhp with stock internals and a P1SC that maxed out a DW300 pump on my 01 Cobra. I am limited by the stock internals.

FYI you are going to reach your limit with belt slip on the six rib setup. Cams are expensive but if you absolutely want them look to Todd Warren Cams / Apocalypse Performane as he is big into the 4V and can custom spec a set for you.


FYI shorty headers are useless for HP gains on the 4V and a set of long tubes does make a difference (I also am running long tubes).

I will look more at your list but a bigger surge (BOV) valve helps if you are going for higher boost. The black “race” valve either open or recirculated j to at least a piece of hose. I have the open black valve and you can hear a LOT of whoosh from that valve in normal driving and the transition from heavy throttle to zero throttle is damn loud. You either like that or don’t.
 
0

01SVTvertt

New Member
Dec 21, 2025
3
0
1
USA
Dec 21, 2025
#4
  • Dec 21, 2025
  • #4
Forgot to mention if you have found the SVTperformance forums yet. You can look in the 99/01 cobra forums and the terminator forums for help. The terminator forums are much busier than the 99/01s.
 
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