I have an 89 GT that I am race prepping for endurance racing. Recently I have discovered that both the rear brake lines and all of the fuel lines running from the charcoal canister or fuel filter have become completely rusted out under the door. I am planning on replacing these, but would like to know a few things first: Is there any disadvantage/danger to running the brake lines through the car instead of outside (trying to avoid a low speed side impact taking out my brakes)? What diameter are the brake lines and what size fittings fit on the stock brake hoses/master cylinder? What diameter are the fuel lines? What type of lines do I need to use for both? I see a lot of different kinds of steel lines, some stainless steel with zinc coating, some just plain cold-rolled steel tubing, what are the different advantages/disadvantages and what do I need to use? Finally, while I am under there, are there any typical parts that fail that should be replaced while I am at it? For other questions or comments about the build for this car, I am planning a whole write up including photos, etc. so please keep this thread only to the fuel and brake line questions. Thanks!
my recommendation would be to replace/upgrade to a teflon braided hose. it's suitable for exotic fuels (e85 etc) and brake fluid. brake lines are norm -3, for fuel, upgrade to bigger size if your planning on e85 or require more fuel for n=bigger inj's turbo. go for -6 feed. if you good quality lines (teflon braid from a repuatble company) then i would'nt worry about having it run thru the cabin, make sure it's not going to rub on sharp edges as always. whetehr it;s legal or not in your state/country is another thing.
This is going to strictly be a race car, no intention of street driving unless it is to an alignment rack or to storage. I am not planning e85 or anything like that, probably just mid grade or higher. As neat as having steel braided lines running all the way to the rear with 5 steel braided lines is not only expensive, but is overkill for what we are doing. Part of the race requirements are that we remain as stock as possible. Relocating the brake lines should be fine so long as we don't gain any performance advantage. We are already sticking with the rubber flex tubing from the end of the solid lines to the calipers, however it is the solid steel lines that need replacing and that we would be running through the cabin. I like your idea of getting bigger fuel lines for future use, however wouldn't that require a higher volume fuel pump? Anything else worth replacing while I am down there? Ive had to remove the steering rack to get to a lot of these items without removing the motor+transmission. My two lower transmission/motor mounts are in excellent shape, so nothing to do there. Finally, what are he standard diameters of the tubing for the fuel and the brake lines? and is that inside diameter or outside diameter? Thanks, Sam
i'll have a quick look tonight at the stock dias etc if your in a race class which requires stock config, then yeh i see no resaon to upgrade to bigger fuel lines/fancy lines. the std dia of the lines are enough for substantially more power than stock, which it seems you aren't chasing anyway.
Sam, you're not allowed to post at this forum unless you show us pics of the car. I'm absolutely kidding! Welcome! What side of State Line Road are you on? But seriously......pics!
Ive got pics, they are just not that great right now, ill post some later along with a complete write-up of our progress so far. We are on the Kansas for the most part, but one of us is located in Missouri
hah, my bad. when i started replying about teflon lines and bigger pumps etc i thought you had a gt4, in aus the 3sge was the SX and the 3sfe was ST, so when i read GT i stoopidly assumed turbo....... the STD fuel lines will be ample for a 3sfe, as will the pump, but if your going to race it for 24hrs i'd go fit a new stock replacement pump. toyota genearally used STD sizes acrocc the board for fuel feed/return. the sw20/gt4's have the same 8mmOD feed and ^mmOD return lines and they flow enough for 300+awhp. i don't think the 3sfe will quite make that amount of HP so you shouldn't need to worry about that.
I've thought about a replacement pump, however the fuel system aside from the deteriorating lines, has been excellent. Never a rough idle, never a bad start. I think we might bring a backup pump to the track, but the original one seems to be doing really well. While we are on the topic of fuel, can you or someone explain to me more specifically the importance of the role the charcoal filter plays in the system, and how to tell if one is good or bad? I have two of them and they have a significant difference in weight. Just wondering what might account for that. Thanks!
afaik the charcoal canister is more for "keep the trees green". delete it for track use. http://www.familycar.com/Classroom/emission.htm A charcoal canister is used to trap the fuel vapors. The fuel vapors adhere to the charcoal, until the engine is started, and engine vacuum can be used to draw the vapors into the engine, so that they can be burned along with the fuel/air mixture. This system requires the use of a sealed gas tank filler cap. This cap is so important to the operation of the system, that a test of the cap is now being integrated into many state emission inspection programs. Pre-1970 cars released fuel vapors into the atmosphere through the use of a vented gas cap. Today with the use of sealed caps, redesigned gas tanks are used. The tank has to have the space for the vapors to collect so that they can then be vented to the charcoal canister. A purge valve is used to control the vapor flow into the engine. The purge valve is operated by engine vacuum. One common problem with this system is that the purge valve goes bad and engine vacuum draws fuel directly into the intake system. This enriches the fuel mixture and will foul the spark plugs. Most charcoal canisters have a filter that should be replaced periodically. This system should be checked when fuel mileage drops.
Based on that reason, I was thinking I might need to keep it for two reasons: 1) to be able to use the gas fumes to actually run the engine, and 2, to keep the tank from building up a lot of pressure and then releasing it in the hot pit. I still dont understand why charcoal is used though. Why do i need to trap it closer to the engine if it is still just captured in the tank?
You dont need it to start the engine. Youd just remove the canister, the vent would still be there to stop any pressure buildup. Q: is the race your involved in allow a fuel cell? Just wondering what they allow to prevent fuel starvation etc
They do, however it cannot be any larger than the stock tank's listed volume, so I really don't see a large advantage to getting a fuel cell. Each driver can have at the most 2 hours driving at a time before a pit by rule, and there is enough fuel in the tank to last that long and then some. So are you saying just to vent the fumes out of the car? If that is the case, I might just as well block up the vent. It would save me from running that extra line.
Yes,i would be looking at a way to delete it. Prob remove line ad use a vented filler cap. The reason toconsider a fuel cell is to hold just enough fuel for how ever long a stnt you wat to run, but also to avoid fuel starvation (when fuel is getting low) when cornering. This could end your race sooner than you want.
A fuel cell, while nice, requires a whole lot more construction and fabrication than we have time for. In the future I think we would like to move this direction, but for now the internal baffles should be good enough. This was about fuel and brake lines, what effect would adding larger brakes lines do? Would the increased volume help prevent boiling brake fluid? Will the feel of the brakes get worse than they are now? I ask because it would be easy to buy the bigger lines for all of the lines I need to replace and just put the correct ends on the ones that are important.
At the very least you should remove the shrouds from the inside of the front brake disks to get more cooling. Bigger brakes will be stronger and go a lot further before boiling, a Camry V6 master cylinder is also a worthwile (invisible) upgrade. Whatever car you choose - it's best to swap the brakes + HUB as well or there will be alignment (spacing) issues. Good choices are ST202 (good), Camry/Solara/Windom? V6(better), Lexus E300 (even better), ST205 (best) but will need bigger rims as well (15in min) Try to use twin piston calipers if possible as they tend to dissapate heat better, look at ST165, ST185 etc and you'll also see they have scoops attached to the hub for increased airflow - a simple mod you can do with a piece of alu There is no agency on earth that will argue your brake upgrade as it's safety related, plus the yards are full of the above mentioned cars
There are specific 2x brake rules. That being said a larger floating piston designed brake would easily fall within the 2x rule. That being said we have two issues: 1) I just pressed in new wheel bearings and hubs for the front, so I do not want to change out my hubs again. I currently have the GT-S Knuckles, hubs, and brakes. 2) We dont want to have to go buy 8 more wheels and tires (we only need 4 new wheels and 8 new tires as it is today) just to fit slightly larger brakes. Larger wheels unless they are steel wheels will draw attention and possibly penalty laps. I am going to look up the official rules with regards to upgrades and post them (probably in my all race-car thread) in-case something stands out as a no brainer. Either way, what are the largest calipers/mounts that will bolt right on and fit inside our current setup and is it worth it for the rears too? (the rears we already replaced with GT-S disc brakes with the parking drum brake parts all removed, except of course the drum itself
the largest straight bolt on front upgrade is the rev2 st18x brakes. they have a 278 rotor and single pot caliper. they fit under 15in rims. you don't need to remove the hub/knuckles etc. i'll have to check the shrouds i have, but often the std shrouds also direct air into the rotors to help cool. bigger lines would require more pedal movement to move the extra volume of fluid and give you a softer brake pedal, how much depends on how much bigger you go.
