Black Jack: The show must go on... Installing the TMOSS GT40 Lower
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Nitrous install underway
The setbacks -- all due to buying from the used market :
- Bought 1st MSD Digital 6 Plus from FB marketplace for $300. The guy never shipped... Paypal buyer's protection covered it.
- Bought 2nd MSD Digital 6 Plus from FB marketplace for $300. The box is bad, according to MSD's test procedures & won't crank car. Paypal will also cover this box.
- Bought the GT40 'big shot' plate, which I think is cool, but is unfortunately too incomplete to use (requires 'nitrous logs').
- bought used nitrous kit from the guy I bought black jack back from for $150... Too incomplete to use.
So, I tried to piece things together on the cheap, but to hell with it, I've waited a long time, only to be disappointed when finally trying to put it together... I'm in no way criticizing those who like biding their time, finding things on the cheap, and piecing their way to a build, but this just ain't the way for me... Broke out the wallet and ordered a new Zex kit & new MSD Digital 6 plus... Time to get this F@#$er done.
- Autolite 3923s are in
- Bottle mounted, lines run to engine bay
- nozzle installed into intake elbow
Will relist the bull
assortment of parts for someone else to finish piecing together...
Pics coming soon
The setbacks -- all due to buying from the used market :
- Bought 1st MSD Digital 6 Plus from FB marketplace for $300. The guy never shipped... Paypal buyer's protection covered it.
- Bought 2nd MSD Digital 6 Plus from FB marketplace for $300. The box is bad, according to MSD's test procedures & won't crank car. Paypal will also cover this box.
- Bought the GT40 'big shot' plate, which I think is cool, but is unfortunately too incomplete to use (requires 'nitrous logs').
- bought used nitrous kit from the guy I bought black jack back from for $150... Too incomplete to use.
So, I tried to piece things together on the cheap, but to hell with it, I've waited a long time, only to be disappointed when finally trying to put it together... I'm in no way criticizing those who like biding their time, finding things on the cheap, and piecing their way to a build, but this just ain't the way for me... Broke out the wallet and ordered a new Zex kit & new MSD Digital 6 plus... Time to get this F@#$er done.
- Autolite 3923s are in
- Bottle mounted, lines run to engine bay
- nozzle installed into intake elbow
Will relist the bull
assortment of parts for someone else to finish piecing together...Pics coming soon
Nitrous and associated electronics are in:
Settings:
I currently have the jets for the 150 shot in it. Michael Bell, who's done more nitrous foxes than anyone else I've known, told me not to spray more than a 100 shot unless I'm using a plate between the upper and lower intakes. That's a bummer, because I want over 420rwhp to the tire... A number that's safe for the stock block/internals and gives me a decisive edge over the performance target, the 392 Challengers/Chargers. I think I'm likely to take my chances. Hell, I'm already taking my chances spraying a motor with unknown, but likely in excess of 200k, miles. Frankly, killing this engine over the next few years is inevitable, if not from nitrous, then from mileage. So, I'm already scoping out motors both new and watching the market place to hopefully get ahead of it and have one ready to drop in when the inevitable comes.
I've set the new MSD box's limiter to 6,100, about ~150 RPM below the stock fuel-cut limiter. I've set the nitrous window switch from 3,500 to 5,900. The low end is well above the recommended 3k minimum to prevent over torquing/over nitrousing the cylinders. It also keeps me spraying in 2nd gear, even if I short-shift by as low as 5,250 in first gear. On the high end, it'll cut the nitrous before I hit the spark-cut limiter from the MSD box. I set the WOT switch to 4.3V, and it's seeing 4.5 at WOT.
I also set the MSD box to pull 6* of timing to start, which is consistent with the 2*/50-shot rule of thumb.
Next steps:
I should get a call from a local shop by the end of next week to set up a dyno-appointment. Based on the comments about distribution, I'm going to aim to jet for 11.5:1, which is also what I've always tuned my turbo cars to. I get the impression that the cooling effect of nitrous actually allows for far leaner AFRs approaching 13:1, but on this front I really do prefer to play it safe. They'll also weld in some Wideband O2 bungs for me on the headers.
I've got a fuel pressure & AFR gauge to install in a 2-gauge A-pillar mount, which I might do today.
I also noticed a lean pop, last night, while driving the car for the first time in a while. I think the car runs pig rich at idle & cruise. So, what I suspect is that the 3923s are fouling. However, I'm a little on guard, because I just replaced the injectors. I'll probably pull a couple plugs to take a look.
It's also about time for me to install the Moates Quarterhorse I recently bought.
Edit: Oh, and I made my decision on the gears. 3.73s are on order. They'll put me through the traps at 122mph off of the Spark-limiter.
Settings:
I currently have the jets for the 150 shot in it. Michael Bell, who's done more nitrous foxes than anyone else I've known, told me not to spray more than a 100 shot unless I'm using a plate between the upper and lower intakes. That's a bummer, because I want over 420rwhp to the tire... A number that's safe for the stock block/internals and gives me a decisive edge over the performance target, the 392 Challengers/Chargers. I think I'm likely to take my chances. Hell, I'm already taking my chances spraying a motor with unknown, but likely in excess of 200k, miles. Frankly, killing this engine over the next few years is inevitable, if not from nitrous, then from mileage. So, I'm already scoping out motors both new and watching the market place to hopefully get ahead of it and have one ready to drop in when the inevitable comes.
I've set the new MSD box's limiter to 6,100, about ~150 RPM below the stock fuel-cut limiter. I've set the nitrous window switch from 3,500 to 5,900. The low end is well above the recommended 3k minimum to prevent over torquing/over nitrousing the cylinders. It also keeps me spraying in 2nd gear, even if I short-shift by as low as 5,250 in first gear. On the high end, it'll cut the nitrous before I hit the spark-cut limiter from the MSD box. I set the WOT switch to 4.3V, and it's seeing 4.5 at WOT.
I also set the MSD box to pull 6* of timing to start, which is consistent with the 2*/50-shot rule of thumb.
Next steps:
I should get a call from a local shop by the end of next week to set up a dyno-appointment. Based on the comments about distribution, I'm going to aim to jet for 11.5:1, which is also what I've always tuned my turbo cars to. I get the impression that the cooling effect of nitrous actually allows for far leaner AFRs approaching 13:1, but on this front I really do prefer to play it safe. They'll also weld in some Wideband O2 bungs for me on the headers.
I've got a fuel pressure & AFR gauge to install in a 2-gauge A-pillar mount, which I might do today.
I also noticed a lean pop, last night, while driving the car for the first time in a while. I think the car runs pig rich at idle & cruise. So, what I suspect is that the 3923s are fouling. However, I'm a little on guard, because I just replaced the injectors. I'll probably pull a couple plugs to take a look.
It's also about time for me to install the Moates Quarterhorse I recently bought.
Edit: Oh, and I made my decision on the gears. 3.73s are on order. They'll put me through the traps at 122mph off of the Spark-limiter.
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I want a custom wet system for the GT40 lower beneath my Kenne Bell so... Become an expert so you can come over and make that happen. 
I don't think it's worth what he's asking, and who know if the solenoids are still functional, but this is the hot ticket for the GT40 style intake, and it'shard to find. I have the plate, but not the "logs" that attach to it. I'm tempted, but can't justify it.
1986-1995 Ford Mustang 5.0L Cobra GT40 Nitrous Oxide Plate NOS 302 351w | eBay
<p dir="ltr" style="margin-top:0; margin-bottom:0;">Old school nitrous oxcide fits cobra & gt40 intake only </p> <p dir="ltr" style="margin-top:0; margin-bottom:0;">Comes as shown was working when removed </p> <br>
www.ebay.com
What’s special about the “logs”? Do the jets go in there? If not then I would think you could make something to attach the solenoid and lines to.
The dyno day is set for 8FEB with a shop in Spring Lake, NC.
Took a little insurance out for my dyno/nitrous day. Figured the Walbro GSS307 (255 LPH) pump that's been in the car since I bought it the first time in 2014, and who knows how much before that, might be a risk. Though the Zex kit is supposed to shut off if the pressure drops to less than 38psi, that would still ruin a perfectly good dyno-day appointment. So, I figured why not spend the $80 & swap in a new 'hi-pressure' Walbro GSS340 in its place? Also found where the smell of fuel's likely been coming from. Looks like it's been leaking around the vent cap. So, I added another O-Ring and made sure the seal when on right. Hope that helps, but didn't have a spare to replace it with and don't know for sure, yet.
Took a little insurance out for my dyno/nitrous day. Figured the Walbro GSS307 (255 LPH) pump that's been in the car since I bought it the first time in 2014, and who knows how much before that, might be a risk. Though the Zex kit is supposed to shut off if the pressure drops to less than 38psi, that would still ruin a perfectly good dyno-day appointment. So, I figured why not spend the $80 & swap in a new 'hi-pressure' Walbro GSS340 in its place? Also found where the smell of fuel's likely been coming from. Looks like it's been leaking around the vent cap. So, I added another O-Ring and made sure the seal when on right. Hope that helps, but didn't have a spare to replace it with and don't know for sure, yet.
You know, they say...
Here's what that looked like for me, this weekend:
I don't even know WTF that was. How does that happen?! I just kept trying to hit it with my allen wrench and couldn't figure out why I couldn't even get a smaller one on there. Once I got the mirror out, I scratched my head and tried for about an hour to get vice-grips, pliers, anything I could do to get on that damned thing, and it was all a no-go... It was just too close to the firewall, and in the middle of everything back behind the Throttle body was also in the way, which led to this:
That was ok, though. It was good to get in there and clean a few things up.
So, what I originally thought was gonna be a 20 min just to replace a Kirban AFPR with an Accufab to gain an extra port for a fuel pressure gauge I'm installing ended up taking all afternoon just to swap it. I guess I'll do the gauge after work one night, or next weekend.
Noticed a lot of oil in the runners. Should I be worried? There's no EGR. So, I guess it must be sucking some of it up through the filler neck an into the tube that runs to the TB.
There we go... Much better!
Here's what that looked like for me, this weekend:
I don't even know WTF that was. How does that happen?! I just kept trying to hit it with my allen wrench and couldn't figure out why I couldn't even get a smaller one on there. Once I got the mirror out, I scratched my head and tried for about an hour to get vice-grips, pliers, anything I could do to get on that damned thing, and it was all a no-go... It was just too close to the firewall, and in the middle of everything back behind the Throttle body was also in the way, which led to this:
That was ok, though. It was good to get in there and clean a few things up.
So, what I originally thought was gonna be a 20 min just to replace a Kirban AFPR with an Accufab to gain an extra port for a fuel pressure gauge I'm installing ended up taking all afternoon just to swap it. I guess I'll do the gauge after work one night, or next weekend.
Noticed a lot of oil in the runners. Should I be worried? There's no EGR. So, I guess it must be sucking some of it up through the filler neck an into the tube that runs to the TB.
There we go... Much better!
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I'm at the dyno, now. We've made a few test/baseline passes. I was surprised to see it range from 260-268.
It has slightly edged over 270 in the couple dyno pulls I've done with it in the past, but I think thise were with U/D pullies and the T5 trans. Now, the stock pullies & T56 trans are on it. So, I'd say that with different day/different dyno, it's too negligible to say that the T56 has really cost much power... Maybe 10?
Getting started with the nitrous passes, now. It ran a bit lean on the baseline passes. So, I'm starting with 100 shot nitrous and 125 fuel fuel jets, aiming for as rich as 11.5:1 to protect from any distribution issues. First nitrous attempt didn't work out.
So, we're diagnosing why the nitrous didn't activate... Hope Black Jack's 150-200k shortblock holds together boys. Keep your fingers crossed for me!
It has slightly edged over 270 in the couple dyno pulls I've done with it in the past, but I think thise were with U/D pullies and the T5 trans. Now, the stock pullies & T56 trans are on it. So, I'd say that with different day/different dyno, it's too negligible to say that the T56 has really cost much power... Maybe 10?
Getting started with the nitrous passes, now. It ran a bit lean on the baseline passes. So, I'm starting with 100 shot nitrous and 125 fuel fuel jets, aiming for as rich as 11.5:1 to protect from any distribution issues. First nitrous attempt didn't work out.
So, we're diagnosing why the nitrous didn't activate... Hope Black Jack's 150-200k shortblock holds together boys. Keep your fingers crossed for me!
Do you do the dyno pull with the Trans in 1-1 or do you use an overdrive gear????
Try swapping in this intake and let us know if it makes a difference:
I think you will hate it but I've been wrong before
kennebell.net
I think you will hate it but I've been wrong before
Mustang 5.0L 1986-1993 Fox Body Supercharger Kit - Kenne Bell Superchargers
Mustang 5.0L 1986-1993 Fox Body Supercharger Kit! Get the performance you've been looking for with this powerful Mustang supercharger. This state-of-the-art Ford 5.0L supercharger kit takes your
kennebell.net
you could have called me with that question, I wouldn't have laughed too long,
Seriously, you can do it in reverse but you have to have a multiplier, that's why most do it in 4 gear on a stick, 1-1, cause we're really bad at math.
A detail I didn't include here was that I asked Rick's thoughts on keeping the King Cobra and putting a ceramic disk in to increase the torque capacity of the clutch... I was trying to save a little $$$, but was looking for maybe 450 rwhp out of this setup. He picked a disk he thought would get me there.
Welp, I appreciate the effort, but now I wish I'd just bit the bullet and got one with a higher capacity. Today's dyno was neither a catastrophic failure nor a great success. We think the clutch disk slipped and I'll explain after each dyno graph how things went:
Graph 1. Best Baseline:
Obviously it ran right up to the limiter. This was actually NOT the best pass power-wise, but we did get the AFR where I wanted to see it, and SAE came in at ~260 rwhp. To get there, I bumped the fuel pressure from 39 psi to ~42 psi. In earlier runs, it was seeing something 14:1 and never dropped below 13.7. But... it made 268 SAE. So, I'm thinking that the tailpipe Wideband was reading leaner than reality. Still... was going the safe rather than sorry route.
I wouldn't have pressed on getting a nice fat AFR, except I wanted to be conservative while prepping to hit it with a shot of nitrous. I am terribly unimpressed witht he 280 rwtq. The car has put down 311 ft-lbs before Link to previous dyno. So, really no idea why it's a dog down low now. Didn't really notice it while at the shop. Feels fine on the street. Thoughts?
The nitrous system is set up to spray between 3500 through 5800 RPM.
Best nitrous pass:
The jets on this pass were 100-shot for nitrous & 125 fuel). So, it picked up 65 rwhp. Fuel looks fine. Again, I'd really expect more torque down low with the nitrous spraying. The next graph gives me an idea:
These are the same 2 graphs laid over each other and on an RPM scale. Look what happens at 5200 or so. I think that is probably clutch slip. I really can't explain the AFR. It's all over the place there, but it doesn't look at all like that when charted against speed.
So, after that run, I pulled the plug. I'm gonna have to get my gauges installed & review what the AFR looks like upstream from the tailpipe, hook up the quarter horse & play with the tune, validate that clutch slip is what we're seeing, and then swap to something a little stouter like a spec2 or a Ram. Then, I'll go back and up the pills to a 150.
Just axin a question... I have never been to a dyno or had any of my cars on one...
Sorry bud.. Thought you were joking. 1:1 (4th in our cars) is standard practice, but as far as I'm aware, dynos don't really care what gear you're in as long as you don't exceed their speed rating or ability to measure torque.
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