Thanks for the detailed write-up, GG. It will be interesting to see your comparison when you are able to stroke it.
Gorilla's grand touring TJ
- Thread starter GoldenGorilla
- Start date
GoldenGorilla
Everybody thought it was crazy. We all know
Original poster
Lifetime Supporting Member
GoldenGorilla
Everybody thought it was crazy. We all know
Original poster
Lifetime Supporting Member
NRT fuel rail, fuel pressure sender, 24 lb/hr injectors
I wanted the ability to monitor fuel pressure as I increase load. I found the NRT rail recommended and reached out to the owner with a few questions. The rail has the ability to thread a fuel gauge into the front end, but the high position of the belts and AC lines on a late TJ 4.0 make that impractical. If you want to do that, a little brass right angle adapter should work.
A Honeywell fuel pressure sender for 0-100 psi threaded for 3/8 NPT fits and has plenty of room for the wiring harness to route up with the fuel injector harness. This is a 5v 3 wire system with ground, +5v and signal wires. I'll feed the signal to HPTuners prolink and apply the scaling formula in a custom field, but you could send it to a gauge. I used some Gasoila thread lubricant/sealant for this. It's a special PTFE thread doping product for contact with gasoline and some other solvents that I had on hand from a different car.
On the back of the rail, I've closed it off, but you could run a fuel system return line to the 8 ORB port or install a damper. Notably the later stock fuel rails have a damper, but no Schrader port.
The rail accepts USCAR EV 6 60mm injectors like stock. I found it was cheaper to buy a new set of 8 Mustang 5.0 Ford Performance purple injectors than 6 from any vendors selling for Jeep. Look around. The Ford Performance ones are a 6 hole Bosch. Part number is M-9593-LU24A for the 8 pack.
I haven't wired in the sensor yet. I don't think I'm going to do many 5V sensors in the future, but if someone has a recommendation for a 5V stepdown that can support more than one sensor circuit, I'm interested. I don't want to tap one of the factory 5V circuits for this sensor and risk an electrical issue on a mod creating a problem that's hard to trace.
The downside to this fuel rail vs stock is that aluminum conducts heat and under the TJ hood it can get very hot. I haven't had vapor lock, but have experienced rough idle on hot starts in 100F days.
I've acquired a fuel return system from TexasJeepProducts to alleviate that tendency. We're getting into slightly cooler weather, so that's a problem for future me. Key on for a few seconds at startup and it should cycle some cooler fuel into the rail. That return system has a slightly lower non-adjustable PSI setting for an 03/04 TJ, and about 12psi lower than an 05/06. This might affect the fueling trim a bit more on an 05/06 so you'll probably want to monitor the LTFT if you're considering it. It might be necessary to apply some injector scaling so you don't run lean under high rpm WOT.
I wanted the ability to monitor fuel pressure as I increase load. I found the NRT rail recommended and reached out to the owner with a few questions. The rail has the ability to thread a fuel gauge into the front end, but the high position of the belts and AC lines on a late TJ 4.0 make that impractical. If you want to do that, a little brass right angle adapter should work.
A Honeywell fuel pressure sender for 0-100 psi threaded for 3/8 NPT fits and has plenty of room for the wiring harness to route up with the fuel injector harness. This is a 5v 3 wire system with ground, +5v and signal wires. I'll feed the signal to HPTuners prolink and apply the scaling formula in a custom field, but you could send it to a gauge. I used some Gasoila thread lubricant/sealant for this. It's a special PTFE thread doping product for contact with gasoline and some other solvents that I had on hand from a different car.
On the back of the rail, I've closed it off, but you could run a fuel system return line to the 8 ORB port or install a damper. Notably the later stock fuel rails have a damper, but no Schrader port.
The rail accepts USCAR EV 6 60mm injectors like stock. I found it was cheaper to buy a new set of 8 Mustang 5.0 Ford Performance purple injectors than 6 from any vendors selling for Jeep. Look around. The Ford Performance ones are a 6 hole Bosch. Part number is M-9593-LU24A for the 8 pack.
I haven't wired in the sensor yet. I don't think I'm going to do many 5V sensors in the future, but if someone has a recommendation for a 5V stepdown that can support more than one sensor circuit, I'm interested. I don't want to tap one of the factory 5V circuits for this sensor and risk an electrical issue on a mod creating a problem that's hard to trace.
The downside to this fuel rail vs stock is that aluminum conducts heat and under the TJ hood it can get very hot. I haven't had vapor lock, but have experienced rough idle on hot starts in 100F days.
I've acquired a fuel return system from TexasJeepProducts to alleviate that tendency. We're getting into slightly cooler weather, so that's a problem for future me. Key on for a few seconds at startup and it should cycle some cooler fuel into the rail. That return system has a slightly lower non-adjustable PSI setting for an 03/04 TJ, and about 12psi lower than an 05/06. This might affect the fueling trim a bit more on an 05/06 so you'll probably want to monitor the LTFT if you're considering it. It might be necessary to apply some injector scaling so you don't run lean under high rpm WOT.
GoldenGorilla
Everybody thought it was crazy. We all know
Original poster
Lifetime Supporting Member
Of note, you can't just run 24 lbs injectors on the later TJs that run 49.5 or 59 psi fuel systems. You have to tune down the fuel injector quite a bit or you'll be way too rich on wide open throttle and cost yourself power and they aren't giving me any more power currently. These are going back in after I do the stroker and then I'll bring the pulsewidths back up.
GoldenGorilla
Everybody thought it was crazy. We all know
Original poster
Lifetime Supporting Member
Installing a Camaro electric fan and controller into the TJ
A big thanks to folks who came before figuring this out. For me, while studying some of the engine performance stuff, I came across info from Engine Masters and others on how much power a mechanical pulls from a motor. The numbers are frankly shocking when the clutch is locked, but even unlocked, can easily be consuming 5-8hp while you're cruising down the highway. This has dual impacts in fuel consumed and in power used to do things other than propel the jeep down the highway.
https://wranglertjforum.com/threads...pal-19-850-watt-electric-brushless-fan.78963/
I decided to follow this process with a couple small modifications. First I decided to use a SPAL connector rather than join the wires directly. This will make it easier to remove the fan when I need to replace the radiator. I am wired with 6ga wire directly from the battery to the connector, with the female plugs crimped directly to those wires. Second, I decided to use the zenner diode to support a floor for AC protection at start, but I decided to put this on a switch. 3 seasons of the year, I don't use the AC as much and only when moving.
Putting it to the test
In June I pushed this offroad in the Maze district of Canyonlands trying various upper limits in 100F temps crawlin around and monitoring the ODBII ECT readings. Crawling around in 4Lo, I never overheated, but I did run the ECT a bit higher than optimal in a few of the settings. Particularly 220F or higher for the max temp resulted in the fan running too slow and engine temps running in the 220°-225° F range. When I dropped the max temp to 190F, the system stabilized at 201°F and stayed there no matter how steep of long a grade I climbed. At 190, the advantage of the electric fan comes into play at slow speeds. It runs whatever speed it needs to, not just a factor of the engine rpm.
Shortly after that trip I determined the formula for a HPTuners custom field to get the ECT reading. It seemed to work well and the values make sense.
V×1/ 0.0142857143 + 0
With the lower ECT reading in hand and an unusually hot summer, I could go bash around a few scenarios and see those deltas. What I've found is surface street traffic speeds are giving me stable 169°F lower ECT with AC and 201°F upper ECT maintained by a Robert Shaw 330-195 thermostat. When I push hard on big mountain climbs, the fan doesn't appear to be impeding flow. However the temps do rise as speeds rise and even more when climbing steep grades at high speeds. Nothing problematic, but the main ECT is reporting as high as 223°F under the highest loads. On mellower grades with low load I've seen it climb up to 208°F, which shouldn't happen at this speed if it was allowing the airflow through the grill and out under the body.
I've always heard that the TJ aero is bad underhood causing high pressure at speed. Strategic vent placement helps reduce pressure buildup as long as it is in an area of relative low pressure above the hood away from the windshield/cowl area. But I've also noticed the hood lift when driving fast and thought the big gap at the leading edge could be contributing to the high pressure. To test this, I'm going to try to seal this except the area where the intake sits with a D-shaped rubber foam gasket material. I've got some more high speed driving coming up.
A big thanks to folks who came before figuring this out. For me, while studying some of the engine performance stuff, I came across info from Engine Masters and others on how much power a mechanical pulls from a motor. The numbers are frankly shocking when the clutch is locked, but even unlocked, can easily be consuming 5-8hp while you're cruising down the highway. This has dual impacts in fuel consumed and in power used to do things other than propel the jeep down the highway.
https://wranglertjforum.com/threads...pal-19-850-watt-electric-brushless-fan.78963/
I decided to follow this process with a couple small modifications. First I decided to use a SPAL connector rather than join the wires directly. This will make it easier to remove the fan when I need to replace the radiator. I am wired with 6ga wire directly from the battery to the connector, with the female plugs crimped directly to those wires. Second, I decided to use the zenner diode to support a floor for AC protection at start, but I decided to put this on a switch. 3 seasons of the year, I don't use the AC as much and only when moving.
Putting it to the test
In June I pushed this offroad in the Maze district of Canyonlands trying various upper limits in 100F temps crawlin around and monitoring the ODBII ECT readings. Crawling around in 4Lo, I never overheated, but I did run the ECT a bit higher than optimal in a few of the settings. Particularly 220F or higher for the max temp resulted in the fan running too slow and engine temps running in the 220°-225° F range. When I dropped the max temp to 190F, the system stabilized at 201°F and stayed there no matter how steep of long a grade I climbed. At 190, the advantage of the electric fan comes into play at slow speeds. It runs whatever speed it needs to, not just a factor of the engine rpm.
Shortly after that trip I determined the formula for a HPTuners custom field to get the ECT reading. It seemed to work well and the values make sense.
V×1/ 0.0142857143 + 0
With the lower ECT reading in hand and an unusually hot summer, I could go bash around a few scenarios and see those deltas. What I've found is surface street traffic speeds are giving me stable 169°F lower ECT with AC and 201°F upper ECT maintained by a Robert Shaw 330-195 thermostat. When I push hard on big mountain climbs, the fan doesn't appear to be impeding flow. However the temps do rise as speeds rise and even more when climbing steep grades at high speeds. Nothing problematic, but the main ECT is reporting as high as 223°F under the highest loads. On mellower grades with low load I've seen it climb up to 208°F, which shouldn't happen at this speed if it was allowing the airflow through the grill and out under the body.
I've always heard that the TJ aero is bad underhood causing high pressure at speed. Strategic vent placement helps reduce pressure buildup as long as it is in an area of relative low pressure above the hood away from the windshield/cowl area. But I've also noticed the hood lift when driving fast and thought the big gap at the leading edge could be contributing to the high pressure. To test this, I'm going to try to seal this except the area where the intake sits with a D-shaped rubber foam gasket material. I've got some more high speed driving coming up.
Everything I've read said that you could not fit 6 guage wire into that connector, so I planned to run with 8 - which is what I got. Although it looks like on yours the seals are not fully seated, it looks like you made it work. Nice job.
How long is your 8 gauge run back to the power source?
How long is your 8 gauge run back to the power source?
GoldenGorilla
Everybody thought it was crazy. We all know
Original poster
Lifetime Supporting Member
Yeah, I could not get the seals to seat as well as I'd like on 6ga. I used an electric silicone sealant to backfill the connector and then pushed the factory seals up to it.
back along the edge of the fender/hood seam to the battery. 4-5ft?
in your sound deadening efforts, did you ever consider the Hotheads soft top headliner?
https://hotheadheadliners.com/colle.../products/jeep-wrangler-tj-soft-top-headliner
They don't make one for an LJ but the way the back end of the sport bar slopes on the LJ vs the more vertical TJ, I'm not sure the length in the back that the TJ product leaves uncovered would be significant enough to worry about on a frameless/fastback LJ top. I think it has a "sunshade" mode that supports without the top up, that I should be able to make that work under my frameless/fastback top.
https://hotheadheadliners.com/colle.../products/jeep-wrangler-tj-soft-top-headliner
They don't make one for an LJ but the way the back end of the sport bar slopes on the LJ vs the more vertical TJ, I'm not sure the length in the back that the TJ product leaves uncovered would be significant enough to worry about on a frameless/fastback LJ top. I think it has a "sunshade" mode that supports without the top up, that I should be able to make that work under my frameless/fastback top.
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