If you used the Bluepoint tool I referenced and had an issue with grip, then you didn't tighten the wing nuts enough. This tool WILL leave marks on the steel lines, but the line will not move in the tool if you clamp it into a vise to use. The funny looking wing nuts are designed to be used with the tightening bar so you can get some significant leverage on the nuts without the use of a separate wrench. With the tool clamped in a vise and using the included bar on the wing nuts, it gets very tight. Only issue I have had is breaking the double flare mandrel if the tube is not perfectly flat. Using a file after the tube is clamped in the device to make sure the tube end is at the right height and flat to the bar surface reduces the risk of breaking the insert. I do tend to keep 2-3 extra mandrels in the kit because breakage does happen. Make sure to blow out the line after filing.
I literally did break a mandrel on my first attempt (you could probably see it in the picture, first attempt on the far left barely showing a metal piece stuck inside the brake line).
I didn't have a tightening bar, I had to use a wrench. But yea, this tool won't clamp tight enough with just bare hands.
I tested the front brakes for leaks. It had a leak on one of the banjo crush washers because it was over torqued. Thankfully they gave me 2 spare washers. Replaced them, torqued them very gently. Pressure tested over night. No leaks so far. One thing I noticed was that my brake rotors would scrape the brake pad even when there's no pressure applied on the brakes. Is that normal? I haven't installed the wheels yet.
Last edited by ohmygosuness; 06-13-2023 at 11:33 AM.
I literally did break a mandrel on my first attempt (you could probably see it in the picture, first attempt on the far left barely showing a metal piece stuck inside the brake line).
I didn't have a tightening bar, I had to use a wrench. But yea, this tool won't clamp tight enough with just bare hands.
I tested the front brakes for leaks. It had a leak on one of the banjo crush washers because it was over torqued. Thankfully they gave me 2 spare washers. Replaced them, torqued them very gently. Pressure tested over night. No leaks so far. One thing I noticed was that my brake rotors would scrape the brake pad even when there's no pressure applied on the brakes. Is that normal? I haven't installed the wheels yet.
There will always be a bit of contact by the pads to the rotors. However, if you have not done a final bleed and gotten ALL the air out the air in the system will compress and then not allow the pads to retract properly. Just make sure all the air is out.
I usually put fluid in, crack the furthest bleeder screw, and wait for the fluid to gravity feed to that point. I put a bleeder bottle on and sometimes it takes hours for this to happen. Once the fluid is to the furthest point, then I go around and bleed the brakes as normal. Once no air is visible I go and run a few laps. Then I almost always have to bleed again to get everything up to operating readiness.
There will always be a bit of contact by the pads to the rotors. However, if you have not done a final bleed and gotten ALL the air out the air in the system will compress and then not allow the pads to retract properly. Just make sure all the air is out.
I usually put fluid in, crack the furthest bleeder screw, and wait for the fluid to gravity feed to that point. I put a bleeder bottle on and sometimes it takes hours for this to happen. Once the fluid is to the furthest point, then I go around and bleed the brakes as normal. Once no air is visible I go and run a few laps. Then I almost always have to bleed again to get everything up to operating readiness.
Yea I bled the front brakes. It did take me several hours to catch all the leaks. Currently there's no more air bubbles. However, I still think about what you said about having a 90 degree element right after a connection may cause it to "unscrew" over time. I'll try to come up with a solution to fix that.
Does the Mendeola clutch line go down the driver side or passenger side?
For what it's worth I bought this Eastwood brake flaring kit with my MK4 and am now using it on the 818C. its spendy but works really well, saved me alot of headache...
Does the Mendeola clutch line go down the driver side or passenger side?
The Mendeola slave is on the passenger side. I don't know if my car has the clutch line in the stock location but it is on the drivers side. If I did this over I would likely run the clutch line down the passenger side.
It's been around 110 degrees here in the past couple of months. Had difficulty to motivate myself to get some work done on the GTM in this heat. But I got all the brake lines in place. Bled them. Pressure tested. So far, no leaks. Next will be mounting the radiator and AC coils from C6 corvette. I wonder if it's going to fit as well as the C5.
After hours of trying to fit these FF corrugated lines into these adaptors with not much progress, I'm thinking about replacing the FF lines with something else. Anyone have any suggestions? Maybe silicone or aluminum lines?
You don't need any of those separate internal sleeves in the adaptors with the corrugated lines. That's the problem you have there. Yes, you can ditch the corrugated stuff and switch to stainless or alum tubes and silicone elbows, but you will have to bead the ends of the tubes so that the coolant system pressure can't push the joints apart.
Shane Vacek
VRaptor SpeedWorks, LLC www.vraptorspeedworks.com
Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
Offering a full line of GTM Upgrades and Custom Parts
You don't need any of those separate internal sleeves in the adaptors with the corrugated lines. That's the problem you have there. Yes, you can ditch the corrugated stuff and switch to stainless or alum tubes and silicone elbows, but you will have to bead the ends of the tubes so that the coolant system pressure can't push the joints apart.
Thanks Shane, you're right! It fits good without the sleeves. The sleeves are only for the aluminum hard lines (according to the manual). I may just stick with the corrugated hose for now, and use the FF provided aluminum hard line for the long, straight section inside the tunnel.
I'm also thinking about insulating the crap out of the outlet of the water pump going through the tunnel, since I heard that heat in the cabin may be an issue.
Something on the manual doesn't seem to make sense on this part. It's basically saying to connect the 1.5" diameter hard line to the upper port of the water pump (about 1.25" diameter). While connecting the 1.25" diameter hardline to the lower port (1.5" diameter). Why are the lines not connecting to ports with their corresponding sizes? (1.25" line to 1.25" port, etc)
Not sure of their thinking on the sizes of the coolant lines, but it works. As far as insulating goes, I've found that the most effective way to do that is to insulate both hard lines with some form of "sleeve" insulation over the tubes, then once all of the coolant and AC hoses are in place, make a "blanket" that spans from one side of the tunnel to the other and seal the blanket to the chassis with foil tape. I've used the foil-faced bubble wrap stuff for this and it works very well....dome it up so that it doesn't contact the tubes......and then use louvered belly pans so that all of the heat from the coolant tubes, heater hoses and AC hoses all gets vented out the bottom of the car.
Shane Vacek
VRaptor SpeedWorks, LLC www.vraptorspeedworks.com
Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
Offering a full line of GTM Upgrades and Custom Parts
You may also know from previous posts that we pioneered the outside the car water lines in the rocker panel area. I would never build a GTM without doing this upgrade. It takes all the heat issues outside of the cockpit.
Now the truck radiator has a cooling system design standard 1.5" inlet and a 1.75" outlet. Because of the size difference there will naturally be a pressure difference designed into the system...as it should be. I went ahead and put a 1.5" line on the top water pump outlet and ran it to the 1.5" inlet on the radiator, and then changed all the radiator out lines right up to the thermostat housing to 1.75" with a reducer at the thermo housing.
I also redesigned the header tank and overflow tank systems.
The result? I had to put a 190 degree thermostat in the water pump housing and also put duct tape across the front radiator opening in order for the engine to not run too cold. And this is with the Katech engine that we recently put in that has got a considerable higher output than the crate 525 LS3 we have been running previously.
I also upped the oil cooler to a pretty large Fluidyne unit.
Bottom line...engine runs right where we set it, the driver is cooler, and we don't have to worry about cooling...EVER.
Unless, of course, we go to something like a 1200 HP mill. That is not happening though.
For the record, we run an entirely closed bottom car with no venting or air flow to the tunnel or engine compartment from under the car.
Not sure of their thinking on the sizes of the coolant lines, but it works. As far as insulating goes, I've found that the most effective way to do that is to insulate both hard lines with some form of "sleeve" insulation over the tubes, then once all of the coolant and AC hoses are in place, make a "blanket" that spans from one side of the tunnel to the other and seal the blanket to the chassis with foil tape. I've used the foil-faced bubble wrap stuff for this and it works very well....dome it up so that it doesn't contact the tubes......and then use louvered belly pans so that all of the heat from the coolant tubes, heater hoses and AC hoses all gets vented out the bottom of the car.
As long as the setup in the manual works, I'm cool with it. Wrapping the whole thing in a blanket (or even adding a layer of heat shield on the tunnel aluminum panels) was exactly my thought of going about insulating this. I've also thought about building a fan on one end of the tunnel, or even a couple fans in the back of the engine bay to suck out as much air as possible. Kind of simulating a wind tunnel.
You may also know from previous posts that we pioneered the outside the car water lines in the rocker panel area. I would never build a GTM without doing this upgrade. It takes all the heat issues outside of the cockpit.
Now the truck radiator has a cooling system design standard 1.5" inlet and a 1.75" outlet. Because of the size difference there will naturally be a pressure difference designed into the system...as it should be. I went ahead and put a 1.5" line on the top water pump outlet and ran it to the 1.5" inlet on the radiator, and then changed all the radiator out lines right up to the thermostat housing to 1.75" with a reducer at the thermo housing.
I also redesigned the header tank and overflow tank systems.
The result? I had to put a 190 degree thermostat in the water pump housing and also put duct tape across the front radiator opening in order for the engine to not run too cold. And this is with the Katech engine that we recently put in that has got a considerable higher output than the crate 525 LS3 we have been running previously.
I also upped the oil cooler to a pretty large Fluidyne unit.
Bottom line...engine runs right where we set it, the driver is cooler, and we don't have to worry about cooling...EVER.
Unless, of course, we go to something like a 1200 HP mill. That is not happening though.
For the record, we run an entirely closed bottom car with no venting or air flow to the tunnel or engine compartment from under the car.
Crash, now you have me day dreaming and scheming about a new setup. Rerouting the lines sounds like a great idea. Though, I am curious about how you get them into the rocker panel area. When you said "outside," is it exposed to the outside air?
Do you have both lines sitting next to each other? Or do you have the cooled water line through the tunnel, while the uncooled line outside?
Hot water on driver's side under rocker panel and cool side on passenger side.
It does require quite a few 90 degree and 45 degree both soft and hard bends. I also have the advantage of having a tube beader so I cut to length and then beaded the ends of the tubes.
I did every connection with double hose clamps for two reasons:
1) It is a rule requirement for the racing sanctioning bodies we run under
2) I also used a 30 pound cap that allows me to run the cooling system to 250 degrees without boil over
Double hose clamps is not a big deal if you have the normal 4 hose connections. 8 versus 4 hose clamps used. But when you have a GTM...holy crap I ordered fifty 1.5" and fifty 1.75" clamps. I used 10 silicone elbows on each side so two ends equals 20 single hose clamp connections, equals 40 double hose clamp connections!
If you are just running a street GTM you can use regular rubber elbows and single hose clamps. It is a bit of work though. Just be prepared.
I will note that the fuel tanks are not in the stock location on this race car. I know people have done the conversion to outside lines with the stock fuel tanks, but I am not sure how they ran the water lines around them. I would think the hot would be easy to go over the drivers tank and then down to the rocker area. The cool line I am not sure how that was done on a stock GTM. Maybe someone that has done it can share?
Which port on the pump is the in/outlet? And which port on the radiator is the in/outlet? I would assume the port on the pump with the larger diameter (bottom) is hot water to radiator, is this correct?
I believe the Corvette runs what is termed a "reverse" system. In other words the cool water is at the thermostat and the hot water comes from the port at the top of the pump.
Crash, you've inspired me to relocate the hose (at least the hot one). I've been thinking about it all day. I may have the cold line going through the tunnel and just relocate the hot one somewhere else. Problem is I'm still very early in the build and am still not 100% sure what will be in the way if I were to route this through the passenger side (my preference).
I may have to get back to this later in the build (at least until after I have most of the parts in the car) to know how I can route it and, if necessary, make any modifications to the chassis.
Hot water on driver's side under rocker panel and cool side on passenger side.
It does require quite a few 90 degree and 45 degree both soft and hard bends. I also have the advantage of having a tube beader so I cut to length and then beaded the ends of the tubes.
I did every connection with double hose clamps for two reasons:
1) It is a rule requirement for the racing sanctioning bodies we run under
2) I also used a 30 pound cap that allows me to run the cooling system to 250 degrees without boil over
Double hose clamps is not a big deal if you have the normal 4 hose connections. 8 versus 4 hose clamps used. But when you have a GTM...holy crap I ordered fifty 1.5" and fifty 1.75" clamps. I used 10 silicone elbows on each side so two ends equals 20 single hose clamp connections, equals 40 double hose clamp connections!
If you are just running a street GTM you can use regular rubber elbows and single hose clamps. It is a bit of work though. Just be prepared.
I will note that the fuel tanks are not in the stock location on this race car. I know people have done the conversion to outside lines with the stock fuel tanks, but I am not sure how they ran the water lines around them. I would think the hot would be easy to go over the drivers tank and then down to the rocker area. The cool line I am not sure how that was done on a stock GTM. Maybe someone that has done it can share?
I've been wondering if it's outside (or under the car) what happens if it hits a rock on the highway. My car may see some tracks but it's mainly for the streets, and the roads in Houston are VERY bumpy.
You should not have to change any frame components. We did not.
The tubes are still very much enclosed, just not in the drivers compartment.
They go in the area where the rocker panels are, just outside the frame on each side.
You may note that the next car that FFR built, the 818, the cooling tubes were kept outside the driver's compartment and run along the sides of the car.
The only drawback that we saw to moving these out to the sides was that the tubes are more exposed to an impact in any potential side impact incident. They are VERY low, especially compared to other street car bumper heights, and so this doesn't seem like it is that big of a concern.
Here is a picture before the current redo. It is really pretty straight forward. It just requires a bit of finagling around, particularly on the front, to get through the frame work and hooked up to the radiator.
Here is a picture before the current redo. It is really pretty straight forward. It just requires a bit of finagling around, particularly on the front, to get through the frame work and hooked up to the radiator.
It looks like you have it routed through the wheel well. I'll have to put a wheel on the car to check the clearance.
Did you have any issues when putting the body on the car?
.
Last edited by ohmygosuness; 09-21-2023 at 12:04 PM.
It looks like you have it routed through the wheel well. I'll have to put a wheel on the car to check the clearance.
Did you have any issues when putting the body on the car?
.
Nope. There is lots of room. I did put aluminum shields over the tubes where debris would hit them from the spinning front wheels as a precaution.
So, I noticed on top of the C5 vette radiator (passenger side) there are 2 ports for heater hose. One connects to the vent tube on cylinder head. The other one connects to the surge tank. The radiator I have from C6 vette only have 1 port. Can I still use this radiator? Or do I have to get a different one.
It's just a port to the top of the radiator.....nothing special about it, so there's not going to be any difference whether you hook 2 hoses to the top of the radiator or install a T there and hook one hose to the radiator and the other hose to the T.....
We always relocate the surge tank to the engine bay and hook a short hose and petcock or shut-off to that port on the radiator (and plug the 2nd port) and use the petcock/shut-off to purge the air out of the top of the radiator.
Shane Vacek
VRaptor SpeedWorks, LLC www.vraptorspeedworks.com
Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
Offering a full line of GTM Upgrades and Custom Parts
Thanks, Shane. Good to know it's nothing too important. I'm assuming you also do nothing with the vent tube on the cylinder head and plug off the port on top of the surge tank?
Last edited by ohmygosuness; 10-02-2023 at 11:56 AM.
Head vents must be used. Not doing so can lead to severe engine damage. Another reason surge tank/header tank is moved to engine compartment. Tank needs to be the highest point in the system for system to function properly.
You're right, Crash. After doing a bit of research on the LS forums, it appears that the best place to plumb the head vents would be the highest low-pressure point of the system (water pump inlet) or into the surge tank. I believe the easiest way for me is to plumb it into the port on top of the surge tank. Correct me if I'm wrong.
Yes, the steam vents on the engine need to connect to the surge tank if you have the surge tank mounted in the engine bay. As Crash stated, this is the #1 reason we usually move the surge tank to the engine bay and mount it so that it's higher than the engine......so that any air trapped at the top of the engine can vent to the surge tank so that the engine is completely full of coolant with no air pockets.
With the surge tank mounted up front in the FFR location, you would need to attach that steam vent hose to that port on the top of the radiator, since the surge tank is mounted lower than the engine. The top of the radiator should always be full of coolant since the radiator is lower than the surge tank....so with the vent hose connected there, the engine shouldn't ever be able to suck in air at the steam vents. If you hook that vent hose to the upper port on the surge tank, the steam vents will pull air in from the top of the surge tank and it will be trapped there and your engine will overheat.
Shane Vacek
VRaptor SpeedWorks, LLC www.vraptorspeedworks.com
Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
Offering a full line of GTM Upgrades and Custom Parts
Thanks for the details, Shane.
Where exactly, in the engine bay, should I relocate the surge tank? Only place I'm seeing is on top of one of the panels right behind the fuel tanks, above the wheel well.
I generally suggest that the tank go as high up as you can get it and therefore it should be up towards the engine firewall. I have always put them on the left side as it is less busy as far as wiring goes.
I should note that Shane's tank fits a stock GTM better than the universal tank that I use, although I don't think it gets up quite as high. As I do not currently have the universal tanks in stock, I would highly recommend Shane's model.
I know I said as far forward as you can get, but in the second picture you can see how much fuel system stuff ended up in front of those tanks. This setup, now that I look at the pictures, is probably not much if any higher up in the car than what Shane does.
The three lines connected there are radiator bleed(blue hose), water pump bleed(-3), and steam vent bleed(-4). The return line is off the bottom of the tank and goes back over to the water pump heater hose connection.
I ended up having to add a 4th fitting on there. The fittings you see are steam vent, water pump bleed, and fuel supply. I ended up having to add the fuel return. The fuel return was on the passenger side of the car previously and I was hoping to keep it there, but ended up having to move it to the driver side.
Looks like this step (relocating surge tank) would be something I should do towards the end, after I have all the wiring in place. Also, I just bought the stock C5 vette tank from Amazon. It seems a tad wider than the one you have. I may have to play around with the fitment location after everything else is in place to be able to decide where it will be mounted.
I like your setup, Crash. Very practical. And those AN fittings looks sweet! I think I might get me some. The welds look clean too. My welds look like boogers being smeared.
Where is the bleeder for the water pump? Or is it one of them heater hose ports. It's mentioned in the manual that both heater port connects to the surge tank. I don't see a bleeder.
Last edited by ohmygosuness; 10-03-2023 at 06:47 PM.
We have been looking at issues as they occur on the GTM setup.
I want to put coolant into the system when I put an engine in, fill up the coolant tank, run the engine just long enough to circulate the fluid, top it up, and then not worry about it again.
I don't want to have to start it repeatedly, use a vacuum cleaner to suck fluid to where it should naturally want to go in a properly designed and built system, and I certainly don't want to jack the car up to try and get the cooling system to work properly.
This is why I redesigned the cooling system on the GTM and passed the info on to this community. There is really nothing special about the system once changed over to what I recommend. It is simply changing things to what every vehicle manufacturer uses in every one of their vehicles.
Now, that said, we have seen cavitation issues in the water pump. While a water pump bleed is pretty standard in a racing vehicle, the Vette does not have one from the OEM. I will have to get a picture for you but what I do is put a -3 bleeder hose at the top of the chamber where the water pump impellor is. This allows a small amount of fluid, and any air that could be trapped, to return to the header tank...automatically since the tank is higher than the pump.
There are two really critical areas that IMHO need to be air free. Those would be the cylinder heads, and the water pump. I left the radiator bleed in the system just because the line was already run from a previous iteration of the cooling system, but it is not essential. You can simply bleed the radiator with a petcock valve and the small amount of air that may accumulate at the radiator will really cause no issues.
If the heads get air in them you can very easily lose a head gasket, and if the pump cavitates and fluid is not flowing, again, you can very easily lose a head gasket.
Just study your street car's system and replicate that and you should be good.
Do you need a water pump bleed? It does make the system more failure proof and easier to work with, but whether you use one or not is up to you. It certainly isn't a requirement to have a functioning system. You just may have to start and stop the engine a few times when initially bleeding the system of air. If you do not see a solid circulation of fluid thru your header tank it either is not hooked up correctly, or you have pump cavitation.
I think Shane offers a mounting bracket to relocate the stock tank to the rear? Don't know for sure, but I do know that his aluminum tank installs look really good. You may want to just purchase his entire kit.
Also just a heads up on AN fittings. There is roughly $10,000.00 of AN fittings and hose in the FFR PDG GTM race car. It is not a cheap alternative.
The key to welding, like painting, is prep. Can you screw up a nicely prepped job? Yes. Can you have a beautiful finished job without good prep? No. Make sure to clean everything really well and then you will eliminate that as a cause of bad welds.
It's just a flat plate that welds to the round tube and the 1x1 square tube above the fuel tank. Gets plumbed up the same as it was in the donor Vette. As mentioned in the description, the only lines attached to the radiator are the main feed and return to/from the waterpump....and then at that top RH corner where there is normally 2 hose barbs moulded into the radiator, we plug one of those off and hook up a short hose with a petcock to the other port. This is just to bleed the air out of the top of the radiator. Once you bleed it out initially and then drive the car a few times and bleed it out again, it shouldn't ever need to be messed with again.
Shane Vacek
VRaptor SpeedWorks, LLC www.vraptorspeedworks.com
Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
Offering a full line of GTM Upgrades and Custom Parts
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Originally Posted by crash
(you could probably see it in the picture, first attempt on the far left barely showing a metal piece stuck inside the brake line).
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