12 Second Mustang thinking about NOS

[91StangLX]

Hello all I am new to the board and I wanted to introduce myself. My name is Todd and I have a 1991 Mustang 5.0 LX that puts out 323 HP to the rear wheels and has run a best 12.09 @ 114 mph. I am thinking of adding a ZEX 125 Nitros kit and would like to know what the board thinks about running NOS on a stock bottom end?

My mods are as follows. Stock 1991 Mustang short block with 108,000 miles on it, GT40P Heads ported and polished with Chevy valves 1.90 intake 160 exhaust and a .550 spring kit. Professional Products Typhoon Manifold, Cobra Roller Rocker 1.6 ratio, 65mm Throttle body, 76mm Mass Air, 24 lb injectors, TFS Stage 1 camshaft, MSD 6AL Ignition, MSD Billet Distributer, Art Carr Street/Strip AOD Transmission with a 2600 Stall convertor, 3:73 FRPP Rear Gears, Moser 31 Spline axels and an Eaton Differential, Subframe connectors.

 

[IMissMy93Fox]

I've heard of people running 150 shots on stock motors with no problems, but I would try to keep it around a 100 shot if it was my motor.

 

[hllon4whls]

I am not a nitrous pro, but as long as everything is in good shape in the motor and you have a safe tune, you should be good to go. Number one problem with NOS is a lean condition.
BTW for your information, you will be approaching the limits of the stock block. Also if you plan to run a the track, you will need a 6 point roll bar and seatbelts to run.

 

[91StangLX]

I am not a nitrous pro, but as long as everything is in good shape in the motor and you have a safe tune, you should be good to do.Number one problem with NOS is a lean condition.
BTW for your information, you will be approaching the limits of the stock block. Also if you plan to run a the track, you will need a 6 point roll bar and seatbelts to run.

Yea I have a 6 point roll bar already installed and of course I have seat belts. I am trying to break 11 seconds but it has so far eluded me. My engine is real tight with good compression and no leaks to speak of. Shoulod I use a dry Nos system or spend the extra for a wet system. Also when useing at the track when do you push the button for the nos? ( i.e half way down the track, after your 60 foot etc...)


1991 Mustang LX 5.0 108,000 miles.

Included Mods: GT40P Heads Ported and polished with Stainless Stell Chevrolet Valves 1.90 intake,1.60 exhaust with .550spring kit, 1.6 Pro Form Roller Rockers, Professional Products Typhoon Manifold, 24lb FRPP Fuel Injectors, 255 LPH In-tank Fuel Pump, Holley Adj Fuel Pressure Regulator, TFS Stage 1 camshaft duration @50 Int 221/Exh 225 Lift Int 499/Exh 510, 65mm Throttle Body, 76mm Mass Air, MSD 6AL Ignition and MSD Billet Distributer, Autolight 764 Plugs, FRPP 9mm Spark Plug Wires, Mac Underdrive Pullies, Mac Unequal Length Headers, Mac Pro Chamber, Mac Cat back Exhaust, ART Carr AOD Street Termimator Transmission with a 2600 RPM Stall Convertor, 3:73 Rear Gears with Moser 31 Spline Axels and an Eaton Differential, Sub frame connectors.

Best Quartermile time 12.093 @114.23 MPH Horsepower dynoed @ 323 Rear Wheels

 

[hllon4whls]

Wet, or dry? Dry is simpler to install. Wet has more hp potential if you chose to build a new motor and upgrade.

When you hit the button is dependant on the traction that you have. Some people can leave on the spray, others have to wait until second gear. No matter where you hit it, you should be able to bust into the 11's/

 

[Schlodes]

You have a pretty stout, good running motor that is probably using up alot of them 24 lb injectors.

Going back to 2002, I had a Zex kit before, and I really liked it BTW and would [likely will mid summer after Thumpers, B, and E-brock go on] buy another in a heart beat. I think even on my stock engine, I could have used some 24 lb injectors when going larger than the 100 shot, becuase it just never ever worked right witrh the 125 shot in there and pulled no differently than with the 100 shot... which added 11 MPH to my car when I went from a detuned for nitrous [8* timing, autolite 24s @ .035" instead of stock...] 14.11 @ 97.something to a 13.66 @ 110.67 MPH on the 100 shot!! On the 75 shot I still went 107 MPH that day. My best [back then with stock 3.08 gears, T body, MAF etc] was a timing bumped stock plugged 13.85 @ 100 MPH so the 100 shot still gave me 10 solid MPH over my bumped timing tune. Fuel system was stone stock except for a 255 L/hr pump, but the 125 shot just never worked, even with VP 100 no lead.. it would cut out on a full pass... just didnt not pull like it should have and I just chalked it up to lack of injector.

I think you'll have to step up to 30lbers of you plan to hit your car with a dry kit [Zex dry, is a nice clean easy install] though. But damn, tune that thing in with even the 100 shot and you will be flying at the times and MPH you already have!!!!!!! Do the GT 40Ps up your compression? Lotsa guys use pump gas & but with the extra compression i'd probably be 'safer than sorry' and dump in 7 gallons of 100 octane no lead on an empty tank for anything bigger than the 75 shot. But thats me. Besides, 100 or 125 shot with 10-12* initial will pull better than with 7-8* The 100 octane no lead may not be needed in some cases [lower yer timing way down] but its cheap insurance for an expensive engine rebuild.. is my way of seeing it.

 

[91StangLX]

You have a pretty stout, good running motor that is probably using up alot of them 24 lb injectors.

Going back to 2002, I had a Zex kit before, and I really liked it BTW and would [likely will mid summer after Thumpers, B, and E-brock go on] buy another in a heart beat. I think even on my stock engine, I could have used some 24 lb injectors when going larger than the 100 shot, becuase it just never ever worked right witrh the 125 shot in there and pulled no differently than with the 100 shot... which added 11 MPH to my car when I went from a detuned for nitrous [8* timing, autolite 24s @ .035" instead of stock...] 14.11 @ 97.something to a 13.66 @ 110.67 MPH on the 100 shot!! On the 75 shot I still went 107 MPH that day. My best [back then with stock 3.08 gears, T body, MAF etc] was a timing bumped stock plugged 13.85 @ 100 MPH so the 100 shot still gave me 10 solid MPH over my bumped timing tune. Fuel system was stone stock except for a 255 L/hr pump, but the 125 shot just never worked, even with VP 100 no lead.. it would cut out on a full pass... just didnt not pull like it should have and I just chalked it up to lack of injector.

I think you'll have to step up to 30lbers of you plan to hit your car with a dry kit [Zex dry, is a nice clean easy install] though. But damn, tune that thing in with even the 100 shot and you will be flying at the times and MPH you already have!!!!!!! Do the GT 40Ps up your compression? Lotsa guys use pump gas & but with the extra compression i'd probably be 'safer than sorry' and dump in 7 gallons of 100 octane no lead on an empty tank for anything bigger than the 75 shot. But thats me. Besides, 100 or 125 shot with 10-12* initial will pull better than with 7-8* The 100 octane no lead may not be needed in some cases [lower yer timing way down] but its cheap insurance for an expensive engine rebuild.. is my way of seeing it.

No my compression is still somewhere around 9.5 with the GT40P, the P heads still use the 58cc combustion chambers and these heads with the larger valves and porting added at least 40 horspower to my motor... To say I am impressed with these heads is an understatement, These heads pull strong all the way through 6000 RPM, when my stock E7TEs' would cut out at about 4700 RPM. The price is hard to beat also $694.00 shipped to my door with all work already done. It is a direct bolt in but you will need a .100 thousanths longer push rod. These heads flow 233cfm @ .500 lift. which should top the Thumpers you are thinking of buying. 30lb injectors might not be a bad idea though....

 

[88stangmangt]

ya MM&FF did a article on this a while ago with the zex kit and a 100k+ stock short block and they said it took the 125 shot without a problem. so i would shoot the 75-100 and if you want that et bad enough 125.

 

[MORFORD]

First of all, that's awesome power from that combo. I have close to the same thing, but TF heads and only got 303rwhp. Have you milled the heads any to raise the compression?

For the nitrous, I would get a wet kit, and don't be afraid to run up to a 150 shot. I have the big shot kit on mine which has a 150 shot minimum, but it only dynoed 90hp more. I think the bottle pressure was too low as I didn't have a gauge at the time. The a/f was less than 10:1 at times. I bought a wideband to sort it all out this year though.
I use the WOT switch, and a Jachobs mastermind for safety and to retard the timing. I run on drag radials, so I just launch at a little less than full throttle, and then floor it a little out and it turns on and hooks up pretty good.

 

[IMissMy93Fox]

I would take a look into that NOZ NOSsle or however they spell it kit... it looks pretty cool. Also I've heard good things about Compucar.

 

[91StangLX]

First of all, that's awesome power from that combo. I have close to the same thing, but TF heads and only got 303rwhp. Have you milled the heads any to raise the compression?

For the nitrous, I would get a wet kit, and don't be afraid to run up to a 150 shot. I have the big shot kit on mine which has a 150 shot minimum, but it only dynoed 90hp more. I think the bottle pressure was too low as I didn't have a gauge at the time. The a/f was less than 10:1 at times. I bought a wideband to sort it all out this year though.
I use the WOT switch, and a Jachobs mastermind for safety and to retard the timing. I run on drag radials, so I just launch at a little less than full throttle, and then floor it a little out and it turns on and hooks up pretty good.

Yes the heads were milled 60 thousanths as well. I am suprised that you are only putting 303 to the rear wheels with the TFS heads you should be making a lot more power than 303 RWHP... There is a friend of mine who has a 89 mustang with basically the same setup I am running except for a pair of ported TFS twisted wedge heads and he is putting down 345 @ the rear wheels... His block is a Ford Sportsman 4 bolt main block though... and he is running 10:1 compression...

I am also running a Diablo custom tune chip and that really woke up my combination when I had the chip burned and installed.

 

[MORFORD]

I'm still at 9:1, and the heads aren't ported at all, and I'm using a tremec which takes a little more power, so I guess I'm not too far off. I'm using 1-3/4" longtubes, so maybe that is taking a little more away when on motor. Your friends balanced block probably helps a little too. And if it's a 306, that probably helps too. I'm not disappointed with the power, but we can always use more right?

 

[Ron86GT]

Your car is very strong. With 114 mph, you should hit 11s no problem even without NOS. What's your launch technique and shift points at and also fuel pressure with vacuum off? Is that convertor lockup or nonlockup? For a mild combination, your car is running very healthy. Thanks.

Ron

 

[91StangLX]

I am running a 2600 Stall convertor, but to be honest I do not think it kicks in until about 2800-2900 RPM, I am launching from a dead stop in drive. The Art Carr AOD is a great transmission. It is a lockup convertor by the way. Here is my time slip number.

Time Slip From March 26, 2004
R/T .097
60' 2.115
330 5.330
1/8 8.177
MPH 92.33
1000 10.011
1/4 12.196
MPH 112.73

This was the time I ran last night at Virginia Motorsports Park. I have gone a best 12.09 @ 114, but I mostly average around 12.2 @ 111-113

Below is a list of mods I have done to my car.


91 Stock 108,000 mile 5.0 motor with forged pistons
GT40P Heads Ported and Polished with 1.90 x 1.60 Valves and a .550 lift Spring Kit
1.6 Proform Roller Rockers
Professional Products Typhoon Intake Manifold
Mac Cold Air Induction
TFS Stage 1 Camshaft
65mm TB
76mm MAS
24lb Injectors
Mac Shorty Headers, Mac Prochamber and Mac Cat back Exhaust
MSD 6AL Ignition with MSD Billet Distributer
MSD 9mm Racing Spark Plug Wires
Iridium Plugs
Mac Underdrive Pullies
Art Carr Street Terminator Transmission with a 2600 Stall convertor
FRPP 3:73 rear gears with 31 spline axles, an Eaton 8.8 Differential
Custom Burned Diablo computer chip
255LPH Fuel Pump
Adj Fuel regulater
Set the timing to 16 degrees advance and the fuel to 37 PSI
Eibach Drag 90/10 shocks, FRPP Progressive rate springs
Eibach upper and lower control arms
Sub Frame connectors
QA1 Tubular K Member
Fiberglass hood with 1.5in cowl
Race Weight with driver is 3120
Price to build about 10K

 

[slowhatch82]

your 60' is your problem, you could definitly hit 11's with a better 60. hell i ran a 14.1@94 with a 1.87 in my 82, imagine what kinda time you could pull with a good 60!

 

[TurboNotch]

Just for reference, I have an 87 LX Notch with a little over 130K original miles, been spraying 150 dry for the past 6 months with no problems at all. Keep the oil changed, back off the timing, and don't go crazy with the rpm and I'll tell you what, these little 302's are stout motors. RPM is the big killer when trying to make a stock shortblock live under high HP conditions. And yes, even with a milder setup, the wet kit will make more power than a dry.

Regards,

 

[NeQX]

i have 309 rwhp and run 100shot with 24# injectors I had my car dyno tuned to a 13.1 a/f, 255lph fuel pump, bottle heater...wet kit...hits hard!