HYDRODYNAMIC
Rock Stacker
Fine tuning the drivetrain clearance at the front where the fuel cell and water pump meet and at the transmission pan and sub frame as well as angle.
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Dust Buggy
- Thread starter HYDRODYNAMIC
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HYDRODYNAMIC
Rock Stacker
More measuring.
HYDRODYNAMIC
Rock Stacker
More measuring and pictures.
HYDRODYNAMIC
Rock Stacker
So what are everyone's thoughts on the rear driveline length and angle. I am trying to keep the drivetrain as close to the fuel cell as possible but allow for expansion/bulging of the tank and flexing of the frame and not have the two rub and wear a hole in the tank. I am also trying to keep the rear yoke as low and forward as possible. Ideally I would push the drivetrain back some more to give lots of room but I don't know if the yoke is too far back of the pivot point of the rear links.
For mounting points I have poly bushings at the motor on each side. One stock GM style poly bushing at the trans and plan to use another round poly bushing at the back of the 205 to support the 205 since there is alot of hanging weight off the back. Right now I think that the extra 205 bushing located on the back of the driver output shaft side will be close enough to the center line that there should not be rotational binding during chassis flex. The chassis should be fairly rigid so I assume minimal flex. Speak up if you think that that is too far off the Y type mounting method.
For mounting points I have poly bushings at the motor on each side. One stock GM style poly bushing at the trans and plan to use another round poly bushing at the back of the 205 to support the 205 since there is alot of hanging weight off the back. Right now I think that the extra 205 bushing located on the back of the driver output shaft side will be close enough to the center line that there should not be rotational binding during chassis flex. The chassis should be fairly rigid so I assume minimal flex. Speak up if you think that that is too far off the Y type mounting method.
gt1guy
Apparently a racist
I would do a bushing in a tube (like the engine mounts) at the trans instead of the GM style one. It's centered and matches the allowed movement of the engine mounts so to speak. Any other support mounts I would do with the GM style, for a couple reasons. One, they have a more multi directional movement to them. Two, the pivot point for movement due to chassis flex/engine torque will be off the trans mount, so having them absorb movement from any direction will reduce the chance of "binding".
How long will the rear drive shaft be in those pictures? How much slip will it be using through travel?
With both the engine and the fuel cell up front, it would seem that moving the drivetrain back as far as you can and still have a rear shaft that will live would be optimum. What kind of F/R weight bias are you expecting it to shake out at?
I'd be nervous about 1" between a plastic cell and a small metal tit spinning at 5k rpm. That wont be a slow rub to a hole, that's gonna friction weld itself rather quickly.
How long will the rear drive shaft be in those pictures? How much slip will it be using through travel?
With both the engine and the fuel cell up front, it would seem that moving the drivetrain back as far as you can and still have a rear shaft that will live would be optimum. What kind of F/R weight bias are you expecting it to shake out at?
I'd be nervous about 1" between a plastic cell and a small metal tit spinning at 5k rpm. That wont be a slow rub to a hole, that's gonna friction weld itself rather quickly.
WaterH
Well-known member
I would imagine your driveshaft is about as short as it can be. (That's what I did) I actually called The driveshaft place and said "make it as short as possible" and then I built the truck around it. I'm sure you thought things through better than me, so it will be fine.
HYDRODYNAMIC
Rock Stacker
The drivetrain is welded in. It took notching out the subframe to make room for the transmission pan clearance. The limiting factor was the shifter linkage over the top of the lower link rod end, there was no room or material to remove.
The rear driveline specs:
Full droop limited to 16" travel = 31.4" J/J, 27.3* at top joint and 24* at bottom, 3* difference between joints
Ride height 6" from bump and 10" from full droop = 30" J/J, 9.7* at top joint and 10.4* at bottom, .8* difference between joints
Full bump = 29.2" J/J, 3* difference between joints
Max slip is 2.2"
Slip from ride height to full bump is .8"
Slip from ride height to droop is 1.4"
The rear driveline specs:
Full droop limited to 16" travel = 31.4" J/J, 27.3* at top joint and 24* at bottom, 3* difference between joints
Ride height 6" from bump and 10" from full droop = 30" J/J, 9.7* at top joint and 10.4* at bottom, .8* difference between joints
Full bump = 29.2" J/J, 3* difference between joints
Max slip is 2.2"
Slip from ride height to full bump is .8"
Slip from ride height to droop is 1.4"
HYDRODYNAMIC
Rock Stacker
By moving the engine forward I ran out of room to keep the fuel cell up front. I like the layout better now since the trans cooler is up front and more protected from both dropping off ledges and landing on the rear end as well as gear being over the top of the cooler and blocking air flow and things falling on a flat cooler. The air flow is better for both the radiator and trans cooler. The weight transfer should also be better now putting the fuel towards the rear.
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HYDRODYNAMIC
Rock Stacker
NP205 support is welded out. I went round and round over how to support such a long and heavy drivetrain. The great debate is solid mount vs bushings. Then comes how many bushing and what type and location and what direction.
I tried to keep it a Y pattern with leaf spring bushing at the engine and GM transmission bushing at the bottom of the Y. The leaf bushings have minimal deflection, while the trans bushings have deflection in all axis’s. I believe the rear 205 mount is centered close enough to the 4l80 mount that they should not bind given their deflection.
I tried to keep it a Y pattern with leaf spring bushing at the engine and GM transmission bushing at the bottom of the Y. The leaf bushings have minimal deflection, while the trans bushings have deflection in all axis’s. I believe the rear 205 mount is centered close enough to the 4l80 mount that they should not bind given their deflection.
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HYDRODYNAMIC
Rock Stacker
43” of flex in the rear, I think the front was just about at max with both tires still on the ground.
HYDRODYNAMIC
Rock Stacker
Wobble stoppers are in and keep the shocks and links aligned throughout all range of motion.
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Bitch'n work man 
WaterH
Well-known member
When I see the rear coilovers going to the center of the trailing arms, it kind of makes the "eyeball engineer" in me nervous. I guess you have run all the stress numbers and it's fine? Anyways, all the fab work looks great.
HYDRODYNAMIC
Rock Stacker
The load from the coilovers pushing down is far less than the load from landing on a rock pushing up from the bottom. With the coilover being in the middle, it helps put more of the bending load on the coilover and distributes the load better than if the coilover was at the axle. The bumps are still on the axle where the major loading will occur when sending it.
rattle_snake
Fuckwits
Dope. Awesome work and attention to detail.
HYDRODYNAMIC
Rock Stacker
Reworked the rear fuel cell, radiator, and deck/cargo area. The fuel cell is offset to the driver side for a shorter fill tube and better angle. The fill tube will go through the corner of the deck and have a clear hose for visibility while filling. The radiator is all rubber mounted for vibration resistance. There will be an aluminum diamond plate piece that spans the two tubes under the radiator to protect from obstacles and debris.
I used to notch tube and vacuum up all the chips so I didn't track them all over or get them embedded in the welding leads, it took alot of time to clean up all the chips as they fly everywhere. Finally I figured out I could vacuum as I was cutting to catch the flying chips in the air. It also vacuums out the tube so no chips get left inside and it cools the whole saw all at the same time.
I used to notch tube and vacuum up all the chips so I didn't track them all over or get them embedded in the welding leads, it took alot of time to clean up all the chips as they fly everywhere. Finally I figured out I could vacuum as I was cutting to catch the flying chips in the air. It also vacuums out the tube so no chips get left inside and it cools the whole saw all at the same time.
HYDRODYNAMIC
Rock Stacker
The fuel cell goes up to about halfway on the radiator and it is offset so it covers 37% of the radiator with at least a 1.5" air gap. With the power of the fans and the deep shroud, the air will easily get pulled through the air gap. On top of that the radiator/fan combo should cool twice the horsepower of what I am running.
HYDRODYNAMIC
Rock Stacker
Cooler Tech
The radiator is a 16" x 30" x 2.375" cross flow dual pass bar style with AN20 fittings. The trans cooler is a Thermal Transfer MA32 single pass which is around 15.75" x 16.34" x 2.625" core. The radiator uses dual 500W 14" VA116-ABL505P-105A rated at 1942 CFM each at 150Pa pressure. The trans cooler is a single 300W 15" VA91-ABL326-65A rated at 1357 CFM at 150Pa pressure. The CFM ratings shown are calculated for the style and size of the cores.
The stock 6.0 water pump should flow 22GPM at 1500RPM and 66GPM at 6000RPM
The radiator should remove 196,000BTU/Hr. at 140ETD at 20GPM and 245,000 BTU/Hr. at 140ETD at 66GPM which is equivalent to 77-96HP. 140ETD means 220 degree fluid entering with 80 degree ambient air cooling the radiator.
Rule of thumb: About one third of the heat generated by the engine goes into the coolant/water mixture and must be dissipated by the radiator. That would mean the 96HP x 3 = 288HP, but radiators of this size are commonly used on 600HP KOH cars? At first I was at a loss of the industrial ratings vs what is working. Most industrial ratings are for max output, while rule of thumb for recreational/off-road use is based on average continuous use. A 600HP car at 50% continuous average output now appears to be reasonable or at least a closer match to the calculated industrial ratings. This is also further confirmed by the size of trophy truck radiators coming in at double the core size at 31" x 31" and cooling 900HP but at a higher continuous average output since the style of course and vehicle allows for a higher average speed.
The 4L80 should flow 6GPM (best info I could find) max around 8GPM
The MA32 should remove 50,000BTU/Hr. at 100ETD which is equivalent to 20HP
I plan to run the SBL-TS-165P on the trans cooler which will turn on at 140* and be full speed at 165*. For the radiator I plan to run a 180* thermostat or a restrictor with a SBL-TS-215P which will turn on at 190* and be full speed at 215*
Since the radiator is low and behind the seats there is no supplemental air flow from the vehicle moving so the fans are the only means of cooling. I wanted the cooling system sending the heat out the back and away from the engine and occupants as well as down low to provide better visibility and lower the CG and safer by not having the radiator facing any occupants.
I am running a surge tank with a cap on the high pressure side. The pump has to pump through the block which will drop the pressure down to a return pressure level that just needs to flow through the radiator and back to the suction of the pump.
The block restriction pressure is 25PSI at 4000RPM but a lot of that pressure should be gone once out of the block and only flowing through the radiator.
I found some testing I had done on the MA style cores running water. I was getting 5 PSI at 40 GPM through a 30" x 16" core. The 15 PSI I listed was for oil restriction based off of Thermal Transfers graphs and forgot about converting for water.
If you look at the Trophy truck radiators at 31'x31" with quad fans, they are lying down in the rear so the air flow at speed is not going to do much. Short course trucks are the same way and the fans are doing all the work.
Ultra 4 is not far behind on the HP levels but most are running half the radiator and half the fans.
When they sit and the intake air gets heat soaked by the 1/3 of the heat that does not go into the radiator, like the engine surface, exhaust, trans surface, torque converter, and trans cooler. The surrounding air is heated and the radiators are not bringing in cold fresh air even though the electric fans are pulling the same amount of air as at high speed.
Thought should be put into the air flow coming in and out of the radiators and coolers in a stopped situation. The inlet air should not be coming from something that can heat up. The hot air should be sent away from the vehicle so it does not heat soak something else. For example Spal fan blade profiles can change the discharge angle leaving the fan. The classic surface mount deep curved blade that many use dumps the air in a flood pattern. Where as the new brushless recessed blade design sends the air out in a spot pattern. The spot pattern is going to send the hot air away at a further distance if aimed correctly. My trans fan is the flood style which is fine because it is aiming at the ground and will send hot air more to the sides and out from under the vehicle. A spot discharge would bounce it off the ground , kick up dust and stay around. My rear engine radiator fans are the spot style and shoot all the air straight out the back into the face of the buggy riding my tail. The mid mounted radiators that send the hot air up at an angle is better than straight back which can heat soak the fuel cell or other coolers near by. The tilted front radiators that send the air down under the motor are better than sending it straight back into the engine where it heat soaks the motor.
Attached Files
The radiator is a 16" x 30" x 2.375" cross flow dual pass bar style with AN20 fittings. The trans cooler is a Thermal Transfer MA32 single pass which is around 15.75" x 16.34" x 2.625" core. The radiator uses dual 500W 14" VA116-ABL505P-105A rated at 1942 CFM each at 150Pa pressure. The trans cooler is a single 300W 15" VA91-ABL326-65A rated at 1357 CFM at 150Pa pressure. The CFM ratings shown are calculated for the style and size of the cores.
The stock 6.0 water pump should flow 22GPM at 1500RPM and 66GPM at 6000RPM
The radiator should remove 196,000BTU/Hr. at 140ETD at 20GPM and 245,000 BTU/Hr. at 140ETD at 66GPM which is equivalent to 77-96HP. 140ETD means 220 degree fluid entering with 80 degree ambient air cooling the radiator.
Rule of thumb: About one third of the heat generated by the engine goes into the coolant/water mixture and must be dissipated by the radiator. That would mean the 96HP x 3 = 288HP, but radiators of this size are commonly used on 600HP KOH cars? At first I was at a loss of the industrial ratings vs what is working. Most industrial ratings are for max output, while rule of thumb for recreational/off-road use is based on average continuous use. A 600HP car at 50% continuous average output now appears to be reasonable or at least a closer match to the calculated industrial ratings. This is also further confirmed by the size of trophy truck radiators coming in at double the core size at 31" x 31" and cooling 900HP but at a higher continuous average output since the style of course and vehicle allows for a higher average speed.
The 4L80 should flow 6GPM (best info I could find) max around 8GPM
The MA32 should remove 50,000BTU/Hr. at 100ETD which is equivalent to 20HP
I plan to run the SBL-TS-165P on the trans cooler which will turn on at 140* and be full speed at 165*. For the radiator I plan to run a 180* thermostat or a restrictor with a SBL-TS-215P which will turn on at 190* and be full speed at 215*
Since the radiator is low and behind the seats there is no supplemental air flow from the vehicle moving so the fans are the only means of cooling. I wanted the cooling system sending the heat out the back and away from the engine and occupants as well as down low to provide better visibility and lower the CG and safer by not having the radiator facing any occupants.
I am running a surge tank with a cap on the high pressure side. The pump has to pump through the block which will drop the pressure down to a return pressure level that just needs to flow through the radiator and back to the suction of the pump.
The block restriction pressure is 25PSI at 4000RPM but a lot of that pressure should be gone once out of the block and only flowing through the radiator.
I found some testing I had done on the MA style cores running water. I was getting 5 PSI at 40 GPM through a 30" x 16" core. The 15 PSI I listed was for oil restriction based off of Thermal Transfers graphs and forgot about converting for water.
If you look at the Trophy truck radiators at 31'x31" with quad fans, they are lying down in the rear so the air flow at speed is not going to do much. Short course trucks are the same way and the fans are doing all the work.
Ultra 4 is not far behind on the HP levels but most are running half the radiator and half the fans.
When they sit and the intake air gets heat soaked by the 1/3 of the heat that does not go into the radiator, like the engine surface, exhaust, trans surface, torque converter, and trans cooler. The surrounding air is heated and the radiators are not bringing in cold fresh air even though the electric fans are pulling the same amount of air as at high speed.
Thought should be put into the air flow coming in and out of the radiators and coolers in a stopped situation. The inlet air should not be coming from something that can heat up. The hot air should be sent away from the vehicle so it does not heat soak something else. For example Spal fan blade profiles can change the discharge angle leaving the fan. The classic surface mount deep curved blade that many use dumps the air in a flood pattern. Where as the new brushless recessed blade design sends the air out in a spot pattern. The spot pattern is going to send the hot air away at a further distance if aimed correctly. My trans fan is the flood style which is fine because it is aiming at the ground and will send hot air more to the sides and out from under the vehicle. A spot discharge would bounce it off the ground , kick up dust and stay around. My rear engine radiator fans are the spot style and shoot all the air straight out the back into the face of the buggy riding my tail. The mid mounted radiators that send the hot air up at an angle is better than straight back which can heat soak the fuel cell or other coolers near by. The tilted front radiators that send the air down under the motor are better than sending it straight back into the engine where it heat soaks the motor.
Attached Files
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WaterH
Well-known member
This is good for most of the mess, but it doesn't help my dogs feet much. I don't know how they stand it. I get slivers all the time and I'm not walking barefoot around the mill. I chases him away and get back to work. Next thing I know he's right behind me.
The rear of the buggy looks nice.
HYDRODYNAMIC
Rock Stacker
The Goat Built fuel cell was designed to use the 2001-2003 truck pump. That year pump has a plastic top and QD fittings which will snap if you look at them the wrong way. They also require an external mounted filter/regulator, hoses, and fittings to plumb them all together.
Moving up to the 2005 year pump gets a metal top plate, fittings, and internal filter/regulator. This allows a single fuel line connection and a vent line with a high tech rollover valve. The internal tank pump also has a white plastic sump with a scavenging venturi nozzle at the bottom that uses the excess pumped fuel to pull more fuel into the sump. The sump also has flapper valves so fuel can come up from the bottom but not leak out. The long small QD is the regulated fuel out. The small and large QD on the round riser are the vent/rollover valve connection.
The new pump is larger in diameter with the added parts, so a new fuel cell plate and hold down ring is needed. A little trimming of the inside lip of the fuel cell might be needed depending on when and how it was made. If made to spec of the drawing it should just clear.
Moving up to the 2005 year pump gets a metal top plate, fittings, and internal filter/regulator. This allows a single fuel line connection and a vent line with a high tech rollover valve. The internal tank pump also has a white plastic sump with a scavenging venturi nozzle at the bottom that uses the excess pumped fuel to pull more fuel into the sump. The sump also has flapper valves so fuel can come up from the bottom but not leak out. The long small QD is the regulated fuel out. The small and large QD on the round riser are the vent/rollover valve connection.
The new pump is larger in diameter with the added parts, so a new fuel cell plate and hold down ring is needed. A little trimming of the inside lip of the fuel cell might be needed depending on when and how it was made. If made to spec of the drawing it should just clear.
HYDRODYNAMIC
Rock Stacker
The metal top plate and fittings along with the reduced plumbing and failure points were the big safety reasons for making the swap.
The old pump plate had insert nuts that got in the way of the inner plastic so that is the old trimming you see. The new plate and hold down ring use the outer mounting bolts since there is no room left. Making a new plate also make it easier to weld on the new filler elbow. I removed the small pressure sensor off the top of the pump, it looks like it monitors the tank air pressure probably for emissions. I used the provided rubber seal with a 1/4" bolt to seal it off.
The old pump plate had insert nuts that got in the way of the inner plastic so that is the old trimming you see. The new plate and hold down ring use the outer mounting bolts since there is no room left. Making a new plate also make it easier to weld on the new filler elbow. I removed the small pressure sensor off the top of the pump, it looks like it monitors the tank air pressure probably for emissions. I used the provided rubber seal with a 1/4" bolt to seal it off.
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WaterH
Well-known member
That's really cool. I like the single fuel line. So is that regulator adjustable? Or are most modern engines running the same pressure?
HYDRODYNAMIC
Rock Stacker
The regulator in these pump assemblies are set non adjustable at 60 PSI +/-5 PSI. I believe most of the LS style engines are running this pressure unless modified.
less than 58 and an ls starts getting unhappy. only time ive seen them running more than 60psi at idle is to keep the pressure from dropping on WOT, which i would argue means your systems is not plumbed correctly.
HYDRODYNAMIC
Rock Stacker
Fuel pump and filler tube are in with a new fuel cell plate. The 2005 pumps use a 1/4" thick green o-ring between the pump and the plate so that is sandwiched in there to make the seal. The filler tube is 2" 3A sanitary elbows and barbs with a cam lock fitting nozzle and cap. I plan to get one of the autolock cam lock caps. This is the same one I used on the last buggy and the cams never unlocked or loosened but it would feel safer having the autolock.
caddy_crawler
Member
cool tech, thx for the thread!Just what I needed to lose the external walbro and make the jump to an in-tank pump
