NEW FOX IMPUT/ADVICE

Madness7645

Member
Jun 19, 2019
21
4
13
33
Tampa Bay
Hey there!

This may be a rather lengthy post, but I want to get my situation / questions out there. I've been reading so many posts on this forum the last few weeks, very helpful! I'd like to start off by saying that this forum is great! So much quick feedback and help from the community is very encouraging. If you find yourself reading this and are interested to give feed back, I'd like to thank you now for your time and help! I'd also like to say that I'm a Fox Mustang enthusiast, not an expert. I have some goals in mind and things I would like to do that I will outline below. I take constructive criticism very well. If I say something that sounds crazy, unnecessary or foolish.. I'd love to know what it is and why it wont work. I'm an open book and still learning.

My goal with the car - Make a reliable / fast street car. I have no intention of drag racing at a track or otherwise. It would be nice to crush some souls around town though.

Small back story, I've owned a few fox's as a teen (I'm 32 now) and they have for a long time been my "dream car".. I've always wanted another but the opportunity never really presented itself. Finally, the opportunity did and I bought one blind-ish. Let me explain. My boss had one that he was on the fence about selling it for about a year. He drove it maybe twice that year, but one of those times he let me drive it, and I got the itch. Fast forward to now, him and I are both deployed to Afghanistan and he finds out he is moving and is willing to sell the car. I jumped on the opportunity and bought it, and here we are.

What I purchased, a 91 GT for $3,500. The car has near perfect interior, and few spots on the body that could use minor repair / new paint. As far as the engine and drive train, below I'll list what I know from what he told me. He is no mustang expert, and the things he did tell me about the car seemed like second hand knowledge from the previous owner. He was given a dyno sheet showing 560 RWHP. How accurate that is, I don't know. I know that number is in the danger zone for the block, where in lies most of my concern. I'm worried that someone set this up to just jam a bunch of air and NOS into a stock engine, and I have a may-pop. The two issues that I know of with the car currently are 1) there is white smoke coming from the right bank at idle. From my research, this could be a bad valve seal. He told me it does it at start up and if you drive the piss out of it for an hour or so. There is no oil in the coolant or vise versa. 2) It has a crazy high idle in my opinion. I made a post about this yesterday and got some good feedback for tackling that. Beyond that, the car runs very strong and feels great driving it.

- 5.0 302 (From what I know, was planning at looking at the piston heads / cylinders when I check the heads)
- Aftermarket Headers and exhaust
- V-2 Vortech supercharger (He thinks is pushing 10-12 psi boost currently)
- Unknown Tune system
- 100 shot Nitrous set up
- Electric radiator fans
- Heads are painted red but are unknown until I get home and tear it down. (My thinking was, if the heads have been off, they could be upgraded)
- Stock intake manifold (Upper and lower)
- Unknown rear end gear ratio (He says he spins tires in 3rd gear still, which makes me think they could be stock 2.73's. Unless my understanding of rear end gears are off)

Below I will make a list of the things / upgrades I think are a priority, and where I will likely need the most feedback.

- New upper and lower intake manifold (I did a lot of research and purchased both. I settled on the 1993 cobra upper and lower. From what I've found, these are perfectly fine for a street car and is a decent upgrade over stock. I got them both for $400)
- GT40 or equivalent heads (if not already installed)
- Trick flow stage 1 or E/B/F cam (there is a lot out there on these and I honestly don't know which is best or what I have in it now (its hard to tell with the idle so high))
- 65-70mm throttle body (depending on what it has now)
- Sub frame connectors
- Check rear end gears and upgrade or change depending on the feedback from this forum
- 36 lb fuel injectors / upgraded fuel pump if not already installed (The car runs great currently so very well could be)
- A little mud and new paint
- install 1.7 roller rockers (if not already installed)
- Retune the car after upgrades? (Honestly, I know nothing about tuning or how to do it *NEED HELP*)

Basically, I'm considering these upgrades because they are what I think (definitely not know for sure) are necessary to optimize power and make the boost / fuel flow through the engine safe and more efficiently. If I'm off the mark or missing anything, please say so and why! I'm posting this for help and all feedback.

In closing, I'm just looking for honest feedback and help to get me on the right track with the car I've waited a long time to own! I want to do it right and clean. I have mechanical experience and plan to do this all myself with the help of a friend or two. I'm not exactly on a budget but the warden isn't going to let me throw everything at it right off. This will be done over the next year or so I imagine. Sorry for a post this long, I figured if I tell you everything I know it will help with getting the best feedback sooner. Thank you again for any time and help!!
 
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Madness7645

Member
Jun 19, 2019
21
4
13
33
Tampa Bay
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received_1351562194994566.jpeg
 
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darkfader

Mustang Master
Feb 16, 2017
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Looks like a great start. I know very little about forced induction so I can’t help there, but there are many guys here who can provide expert advice on that and tuning. There’s a tuning forum as well to start reading that may also provide some insight.

You’ll need to get your engine configuration planned out to determine your fueling needs.

For the cam, most will recommend a custom ground cam made specifically for your configuration. That’s the route I went through FlowTech Induction. They are highly recommended by this community. You’ll fill out a form with all of your car’s info and they grind you a cam. I ordered mine roughly two weeks ago so I expect mine to come soon.

For subframe connectors, I recommend Maximum Motorsport full length, weld-in connectors. I recommend MM for any suspension needs. I have basically their entire suspension for a street car and all the components are of high quality and their customer service is excellent.

Keep us posted on how the car comes along and don’t hesitate to ask questions, this is the place for great fox info.
 

DemonGT

Founding Member
May 24, 2002
684
8
39
Sparta,WI
Visit site
Just buy TFS top end kit. Comes with everything you need to install HCI

Had it on my 89 GT and i was happy with it. Was planning a blower but never got that far.
 

Madness7645

Member
Jun 19, 2019
21
4
13
33
Tampa Bay
Looks like a great start. I know very little about forced induction so I can’t help there, but there are many guys here who can provide expert advice on that and tuning. There’s a tuning forum as well to start reading that may also provide some insight.

You’ll need to get your engine configuration planned out to determine your fueling needs.

For the cam, most will recommend a custom ground cam made specifically for your configuration. That’s the route I went through FlowTech Induction. They are highly recommended by this community. You’ll fill out a form with all of your car’s info and they grind you a cam. I ordered mine roughly two weeks ago so I expect mine to come soon.

For subframe connectors, I recommend Maximum Motorsport full length, weld-in connectors. I recommend MM for any suspension needs. I have basically their entire suspension for a street car and all the components are of high quality and their customer service is excellent.

Keep us posted on how the car comes along and don’t hesitate to ask questions, this is the place for great fox info.
Looks like a great start. I know very little about forced induction so I can’t help there, but there are many guys here who can provide expert advice on that and tuning. There’s a tuning forum as well to start reading that may also provide some insight.

You’ll need to get your engine configuration planned out to determine your fueling needs.

For the cam, most will recommend a custom ground cam made specifically for your configuration. That’s the route I went through FlowTech Induction. They are highly recommended by this community. You’ll fill out a form with all of your car’s info and they grind you a cam. I ordered mine roughly two weeks ago so I expect mine to come soon.

For subframe connectors, I recommend Maximum Motorsport full length, weld-in connectors. I recommend MM for any suspension needs. I have basically their entire suspension for a street car and all the components are of high quality and their customer service is excellent.

Keep us posted on how the car comes along and don’t hesitate to ask questions, this is the place for great fox info.
Looks like a great start. I know very little about forced induction so I can’t help there, but there are many guys here who can provide expert advice on that and tuning. There’s a tuning forum as well to start reading that may also provide some insight.

You’ll need to get your engine configuration planned out to determine your fueling needs.

For the cam, most will recommend a custom ground cam made specifically for your configuration. That’s the route I went through FlowTech Induction. They are highly recommended by this community. You’ll fill out a form with all of your car’s info and they grind you a cam. I ordered mine roughly two weeks ago so I expect mine to come soon.

For subframe connectors, I recommend Maximum Motorsport full length, weld-in connectors. I recommend MM for any suspension needs. I have basically their entire suspension for a street car and all the components are of high quality and their customer service is excellent.

Keep us posted on how the car comes along and don’t hesitate to ask questions, this is the place for great fox info.
Thanks for the great info, I will look into one of those cams for sure! The full length subframe connectors are exactly what I'm looking for.
 

Madness7645

Member
Jun 19, 2019
21
4
13
33
Tampa Bay
Just buy TFS top end kit. Comes with everything you need to install HCI

Had it on my 89 GT and i was happy with it. Was planning a blower but never got that far.
I looked into that a few days ago. I figured with the upper and lower intake I already bought, I would make out cheaper and just a quality finding a good pair of used heads and buying the cam new (depending on what I find in there, might already have aftermarket upgrades). If it makes more sense to do so once I tear it down, I will definitely look into it.
 

Mstng93SSP

You have a nice rear end there Dave.
15 Year Member
Nov 29, 1999
2,062
2,393
184
Mililani, Hawaii
Used heads need to be checked out usually, and may need work. Then you need pushrods, roller rockers, gaskets, head bolts, (depending on the head setup you might need new valve covers) etc. I have done it both ways, but I find the TFS top end kit to be complete and works well together.
 
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Steel1

Mustang Master
Aug 18, 2017
1,200
547
143
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Connecticut
Looks like your car is running an fmu which raises the fuel pressure under boost essentially making the injectors bigger.
Seeing this I would guess your still on stock a9l tune.
If your plan is to remove the s/c and nitrous than running the stock ecu should work out ok for you, may want to change injectors
and maf.
Just reread your original post. looks like your keeping the s/c set-up which is cool.
Given that I would verify what size injectors you have as well as fuel pump, fuel delivery is essential in boosted applications.
I've run a few different supercharged set-ups and have done them old school fmu as well as aftermarket chip, ecu.
Imo if staying boosted look into some form of aftermarket tuning device, either chip or ecu.
 
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Madness7645

Member
Jun 19, 2019
21
4
13
33
Tampa Bay
Looks like your car is running an fmu which raises the fuel pressure under boost essentially making the injectors bigger.
Seeing this I would guess your still on stock a9l tune.
If your plan is to remove the s/c and nitrous than running the stock ecu should work out ok for you, may want to change injectors
and maf.
Just reread your original post. looks like your keeping the s/c set-up which is cool.
Given that I would verify what size injectors you have as well as fuel pump, fuel delivery is essential in boosted applications.
I've run a few different supercharged set-ups and have done them old school fmu as well as aftermarket chip, ecu.
Imo if staying boosted look into some form of aftermarket tuning device, either chip or ecu.

Thank you for the help! I definitely plan to stay boosted. After reading your post, I researched the FMU to read up and understand how it works. Researching left me with a few questions.

1) with the s/c running off an FMU (and likely stock tune), does that mean that when I change the heads / cam / intake that it doesn't need to be "re-tuned"? From what I understand of the FMU, I would only change the disc inside (ratio) if I change my injector size. So when I upgrade those things, it won't effect how the car performs adversely like it might if I was chiped or ECU. Am I understanding that correctly?

2) Is there a specific chip / ECU set up that you recommend? From what I'm understating, with larger injectors, the ECU will just adapt the fuel flow depending on the level of boost. Is that correct?

Thank you again!
 

Steel1

Mustang Master
Aug 18, 2017
1,200
547
143
51
Connecticut
You are correct, if you change injector size you would change the fmu disc accordingly, but it is a band-aid of sorts.
Can you run it like that...sure, is it the safest/most efficient to run a boosted car...no.

Normally if you're running a stock ecu and change the injectors you need to use a maf calibrated to the injector size,
stock ecu will not adapt to any injector size.

If you would like to learn how to tune your own vehicle, be able to make changes and tune for them, then I highly recommend
a Megasquirt based ecu.
Recently I purchased and installed a Stinger PimpXS and have been learning as I go, we have a very helpful member on this forum
who will give you all the tuning help you need "a91what". Do a little reading on the digital tuning section of this forum to familiarize yourself.
You also have the option of finding a tuner with a dyno and having them burn you a custom tune on a chip installed in your stock ecu.

If you do chose to stay with the fmu option I would at least upgrade your fuel pump If not done already.
 

Madness7645

Member
Jun 19, 2019
21
4
13
33
Tampa Bay
Update.. over my head but still at it. Headed to a shop to help me put it together before spring. When I got home and poked around, I noticed a few of my gauges would work intermittently. The cause... the fuse box under the dash was completely melted through due to some botched wiring. Did a complete wiring harness replacement (which really took the wind out of my sails). I pulled the engine and replaced all the gaskets and seals, water pump. MSD AL6 w/ boost retareder.

For my budget, went with the following combo
GT40 upper and lower intake
GT40 heads
F303 cam (works well with boosted applications)
3.55 gears.
Removed the nitrous

Went for tried and true 90's power. I know many disagree with this combo, either much more efficient bolt one out there. But for now, that's what my budget can handle. Will post more pics and videos in the coming weeks if anyone is interested!
 

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