The Clublexus Lessons Learned Performance Thread
03-25-11, 03:35 AM
#1
Lead Lap
Thread Starter
The Clublexus Lessons Learned Performance Thread
Greetings...
I've been working on getting my sc300 back into track shape and realized that it wouldn't hurt to share lessons learned - from fuel system, driveline setup, exhaust, turbo selection, standalone, etc. Hopefully, others will contribute making this a useful thread (Lord knows I've posted enough use-less stuff! :-P) I'll start and add items later... Oh, one more thing; any links posted to vendor web sites are not necessarily an endorsement of their products. It's for guidance, only. I do not receive any compensation for posting here; I only want to help the Lexus community.
With that out of the way, on to the fun stuff!
Fuel System:
I've run dual pumps since day one and elected to replace the OEM delivery line with a -8 steel braided line. The OEM return line works fine especially if you stage the second pump to come on at a safe boost level (I programmed it for 14 psi). I prefer a Y-block in the tank although it's a pain to keep it out of the way of the fuel level sender. Others have put the Y block outside the tank with good results, too. At the fuel rail end, you'll need another Y-block if you're planning for a dual-feed system to the injectors.
The other issue is proper selection of fuel lines. I finally settled on bona fide intank high pressure 5/16 SAE J30R10 fuel line from the pumps to the Y-block (read here and search for SAE J30R10: http://www.autoperformanceengineerin...html/kits.html). I suggest using spring retention clamps on the pump side of the line (worm-gear clamps could crush the line and potentially lose pressure over time), and a 6-an fitting on the other end of the fuel line. The 6an fitting will work just as it does on a steel braided line even though the SAE line has no reinforcement (isn't required). To connect the lines to the Y-block, I used a 45 degree 6AN fittings to reduce overall "packaging" of the Y-block and attached fuel lines. This allows easy installation through the fuel tank access hole.
Next is the Y-block. I needed a small block that converted dual 6AN to 8AN, and there are many vendors with good products. I elected to go with Magnafuel (http://www.jegs.com/i/Magnafuel/665/...oductId=751964) They're a bit pricey but worth it. For the 8AN line, I just use standard steel braided fuel line that attaches to an 8AN, 90 degree steel bulkhead fitting. I put the bulk head fitting through the access plate behind the rear seat; however, I suggest instead putting it through the tank somewhere else. There's too much of a chance getting fuel in the cabin of the car when working on the fuel system, and that stinks... literally! :-P
As far as fuel rails go, if you're not making more than about 700whp, STICK WITH THE OEM FUEL RAIL! I converted a stock GE fuel rail to dual feed -center return, and it worked great! It also uses the stock thermal isolators when bolted down and keeps the engine temps off the rail. I currently run an aftermarket rail, and there is no thermal isolation. Consequently, the fuel gets very hot over time. In fact, it sometimes makes the fuel tank hot to the touch.
I'm currently using an Aeromotive FPR, but I'm not a big fan of it. I've had to replace the diaphram twice. So, if you have a better suggestion, I'm all ears. :-)
For fuel pumps, I've used dual walbros most of the time and they've work very well. In fact, I once made over 650whp on one pump by mistake (the second pump did not activate), but I do NOT recommend that approach for obvious reasons. For additional margin, though, I've elected to go with two Densos. Mounting two Densos can be challenging, but the OEM hanger works quite well using steel worm-gear clamps to secure the pumps. Just make sure you vibration isolate the additional pump with a fuel proof rubber pad in between the two. I cut sections from gas tank filler hose to isolate the "on" pump hanging off the "staged" pump attached to the hanger. Then, you don't get a lot of pump noise in the passenger cabin. When the second pump comes on, the sound doesn't matter because you're hopefully blowing the tires off anyway. :-P
I have no lessons learned on injectors. I've used different 720cc and 1000cc injectors, and both worked well.
To pass the power signals through the access plate, I simply drilled holes through the plate, welded a 1/4" tall 1/4" wide steel sleeve over the whole, and then filled it with JB weld. Then, I drilled a long 4/40 screw through the middle of the cured JB Weld and cut the head of the screw off. The JB weld insulates the 4/40 screw from the grounded gas tank, and the threaded ends of the screw are the attachpoints for powering the pumps. I used nylon nuts to insulate the terminal lugs from the steel sleeve on top and access plate on the bottom. Oh... and use a hefty gauge wire if you're going with Densos. I suggest at LEAST a 12 gauge wire; 10 gauge even better. For Walbros, the 12 gauge should be fine.
Finally, don't scimp on the fuel filter. Get a bona fide, high-pressure, in-line fuel filter with a replaceable element. Do it right the first time and don't worry about it later.
That's it for now; I'll probably do driveline next. I look forward to other contributions from CL members. So, please tell us what you've learned!
Thanks,
-scott
I've been working on getting my sc300 back into track shape and realized that it wouldn't hurt to share lessons learned - from fuel system, driveline setup, exhaust, turbo selection, standalone, etc. Hopefully, others will contribute making this a useful thread (Lord knows I've posted enough use-less stuff! :-P) I'll start and add items later... Oh, one more thing; any links posted to vendor web sites are not necessarily an endorsement of their products. It's for guidance, only. I do not receive any compensation for posting here; I only want to help the Lexus community.
With that out of the way, on to the fun stuff!
Fuel System:
I've run dual pumps since day one and elected to replace the OEM delivery line with a -8 steel braided line. The OEM return line works fine especially if you stage the second pump to come on at a safe boost level (I programmed it for 14 psi). I prefer a Y-block in the tank although it's a pain to keep it out of the way of the fuel level sender. Others have put the Y block outside the tank with good results, too. At the fuel rail end, you'll need another Y-block if you're planning for a dual-feed system to the injectors.
The other issue is proper selection of fuel lines. I finally settled on bona fide intank high pressure 5/16 SAE J30R10 fuel line from the pumps to the Y-block (read here and search for SAE J30R10: http://www.autoperformanceengineerin...html/kits.html). I suggest using spring retention clamps on the pump side of the line (worm-gear clamps could crush the line and potentially lose pressure over time), and a 6-an fitting on the other end of the fuel line. The 6an fitting will work just as it does on a steel braided line even though the SAE line has no reinforcement (isn't required). To connect the lines to the Y-block, I used a 45 degree 6AN fittings to reduce overall "packaging" of the Y-block and attached fuel lines. This allows easy installation through the fuel tank access hole.
Next is the Y-block. I needed a small block that converted dual 6AN to 8AN, and there are many vendors with good products. I elected to go with Magnafuel (http://www.jegs.com/i/Magnafuel/665/...oductId=751964) They're a bit pricey but worth it. For the 8AN line, I just use standard steel braided fuel line that attaches to an 8AN, 90 degree steel bulkhead fitting. I put the bulk head fitting through the access plate behind the rear seat; however, I suggest instead putting it through the tank somewhere else. There's too much of a chance getting fuel in the cabin of the car when working on the fuel system, and that stinks... literally! :-P
As far as fuel rails go, if you're not making more than about 700whp, STICK WITH THE OEM FUEL RAIL! I converted a stock GE fuel rail to dual feed -center return, and it worked great! It also uses the stock thermal isolators when bolted down and keeps the engine temps off the rail. I currently run an aftermarket rail, and there is no thermal isolation. Consequently, the fuel gets very hot over time. In fact, it sometimes makes the fuel tank hot to the touch.
I'm currently using an Aeromotive FPR, but I'm not a big fan of it. I've had to replace the diaphram twice. So, if you have a better suggestion, I'm all ears. :-)
For fuel pumps, I've used dual walbros most of the time and they've work very well. In fact, I once made over 650whp on one pump by mistake (the second pump did not activate), but I do NOT recommend that approach for obvious reasons. For additional margin, though, I've elected to go with two Densos. Mounting two Densos can be challenging, but the OEM hanger works quite well using steel worm-gear clamps to secure the pumps. Just make sure you vibration isolate the additional pump with a fuel proof rubber pad in between the two. I cut sections from gas tank filler hose to isolate the "on" pump hanging off the "staged" pump attached to the hanger. Then, you don't get a lot of pump noise in the passenger cabin. When the second pump comes on, the sound doesn't matter because you're hopefully blowing the tires off anyway. :-P
I have no lessons learned on injectors. I've used different 720cc and 1000cc injectors, and both worked well.
To pass the power signals through the access plate, I simply drilled holes through the plate, welded a 1/4" tall 1/4" wide steel sleeve over the whole, and then filled it with JB weld. Then, I drilled a long 4/40 screw through the middle of the cured JB Weld and cut the head of the screw off. The JB weld insulates the 4/40 screw from the grounded gas tank, and the threaded ends of the screw are the attachpoints for powering the pumps. I used nylon nuts to insulate the terminal lugs from the steel sleeve on top and access plate on the bottom. Oh... and use a hefty gauge wire if you're going with Densos. I suggest at LEAST a 12 gauge wire; 10 gauge even better. For Walbros, the 12 gauge should be fine.
Finally, don't scimp on the fuel filter. Get a bona fide, high-pressure, in-line fuel filter with a replaceable element. Do it right the first time and don't worry about it later.
That's it for now; I'll probably do driveline next. I look forward to other contributions from CL members. So, please tell us what you've learned!
Thanks,
-scott
Last edited by motorheaddown; 03-25-11 at 04:50 AM.
06-21-11, 08:37 AM
#2
Been doing some research on a overkill fuel system on my sc300. Any insight on how to keep it simple but still flow 800+.
Looks like what most people run is dual intank, one through the stock fuel feed, one through a -6an bulkhead / separate line to the front of the engine bay. I'm considering an aftermarket rail from fsmoto and run 1 line per side of the rail and out the middle for the fuel pressure regulator and back through the stock fuel return.
Looks like what most people run is dual intank, one through the stock fuel feed, one through a -6an bulkhead / separate line to the front of the engine bay. I'm considering an aftermarket rail from fsmoto and run 1 line per side of the rail and out the middle for the fuel pressure regulator and back through the stock fuel return.
06-21-11, 09:33 AM
#3
gte & na-t
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I am in the same boat and going back and forth on the fuel setup specially the tank.
But i am a little confuse about the whole thing because i was looking at the botton of the fuel tank and
lol but i will figure something out and post it on my thread.
But i am a little confuse about the whole thing because i was looking at the botton of the fuel tank and
lol but i will figure something out and post it on my thread.
06-21-11, 12:12 PM
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I'll share my lessons learned on fuel system upgrades.
I've always run twin Walbros intank. I attached them to the stock hanger with a worm gear clamp and 30R10 hose between the pumps to act as an isolator. I removed the stock bulkeah and welded -6AN bungs to each side of it. Inside the tank, I attached 3/8" 30R10 hose to each pump and ran them to the bulkhead with -6AN fittings. For the electrical, I drilled an additional hole in the bulkhead, ran the wires through and used 100% silicone adhesive to seal it. Never had any signs of leaks.
I ran two -6AN Aeroquip Socketless hose to each end of the fuel rail with Russell stainless stell filters in each line. The fuel rail is a Fuel Injector Clinic with 1000cc injectors and I was using an Aeromotive FPR. I removed the stock fuel return line from the car and capped it under the gas tank. I used the stock fuel feed line as the return line but I removed the stock feed line back to the fuel filterWith the bigger return line, I never had to worry about my base fuel pressure. I could lower it as much as I wanted with both pumps on.
After all that, I wouldn't suggest going that route to anyone that wants a high horsepower car. I learned to get the biggest injector you can manage. If you think you only want 700whp, get 2150cc injectors just in case. I'm on my third set of injectors. Granted, the 2150cc weren't available when I was building my car and anything over 1000cc was stupid at the time but for all you guys starting out, get the biggest you can tune for.
I've also ditched the dual intake pumps. Run a single pump!! I was always a single pump hater when my dual walbros worked reliably and I've never had a problem but now that I'm going with a single Magnafuel pump, I'll never look back.
The SC has a unique fuel tank and you'll have to be creative when installing a single pump (unless you install it intank) but I'm sure there are some threads somewhere that show pictures of my setup.
I've always run twin Walbros intank. I attached them to the stock hanger with a worm gear clamp and 30R10 hose between the pumps to act as an isolator. I removed the stock bulkeah and welded -6AN bungs to each side of it. Inside the tank, I attached 3/8" 30R10 hose to each pump and ran them to the bulkhead with -6AN fittings. For the electrical, I drilled an additional hole in the bulkhead, ran the wires through and used 100% silicone adhesive to seal it. Never had any signs of leaks.
I ran two -6AN Aeroquip Socketless hose to each end of the fuel rail with Russell stainless stell filters in each line. The fuel rail is a Fuel Injector Clinic with 1000cc injectors and I was using an Aeromotive FPR. I removed the stock fuel return line from the car and capped it under the gas tank. I used the stock fuel feed line as the return line but I removed the stock feed line back to the fuel filterWith the bigger return line, I never had to worry about my base fuel pressure. I could lower it as much as I wanted with both pumps on.
After all that, I wouldn't suggest going that route to anyone that wants a high horsepower car. I learned to get the biggest injector you can manage. If you think you only want 700whp, get 2150cc injectors just in case. I'm on my third set of injectors. Granted, the 2150cc weren't available when I was building my car and anything over 1000cc was stupid at the time but for all you guys starting out, get the biggest you can tune for.
I've also ditched the dual intake pumps. Run a single pump!! I was always a single pump hater when my dual walbros worked reliably and I've never had a problem but now that I'm going with a single Magnafuel pump, I'll never look back.
The SC has a unique fuel tank and you'll have to be creative when installing a single pump (unless you install it intank) but I'm sure there are some threads somewhere that show pictures of my setup.
06-21-11, 01:23 PM
#7
gte & na-t
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^thanks for sharing i am trying to stay away from dual or triple pumps if i can, i would like to run the Fuelab 41402 progidy fuel pump but my friend recommend the Weldon.
i like the idea of (1) big pump but will see what happen.
Please post some pics of you single pump setup and what's require to install on the SC.
i don't like maxing out my fuel setup, i like overkill on fuel system.
i like the idea of (1) big pump but will see what happen.
Please post some pics of you single pump setup and what's require to install on the SC.
i don't like maxing out my fuel setup, i like overkill on fuel system.
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06-21-11, 01:56 PM
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There are many choices for aftermarket single fuel pumps (Magnafuel, Fuelab, Weldon, etc.) Weldon is a big name that most people go with but they require a controller.
I went with Magnafuel because they've been around forever, their pumps are rebuildable and they can be run continuously (no need for a controller).
I went with Magnafuel because they've been around forever, their pumps are rebuildable and they can be run continuously (no need for a controller).
Last edited by DaveGS4; 06-21-11 at 02:33 PM.
06-21-11, 01:57 PM
#9
I've also ditched the dual intake pumps. Run a single pump!! I was always a single pump hater when my dual walbros worked reliably and I've never had a problem but now that I'm going with a single Magnafuel pump, I'll never look back.
The SC has a unique fuel tank and you'll have to be creative when installing a single pump (unless you install it intank) but I'm sure there are some threads somewhere that show pictures of my setup.
Are you talking about this kit?
http://www.magnafuel.com/products/kits/MP-4813.htm
You could have a bulkhead installed on the bottom of the tank and feed that monster pump.
Last edited by HiPSI; 06-21-11 at 02:03 PM.
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