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It ruins weight distribution not in a static front weight versus rear weight sense (as that can and has been dealt with by moving components to the rear of the car).
It ruins weight distribution in the dynamic sense (how weight distribution affects vehicle movement) by moving weight toward the extreme ends of the car, so increasing the polar moment of inertia.
Not to beat a dead horse but allow me to elaborate a bit and try to give a visual and experiment of what Blue is explaining here. Grab a bench press bar and put two 10lbs weights on the very tips with you lifting from the center with one arm. Your center balance with your arm is the 50/50 center around rotation because the bar is level. Now using your wrist try to rotate that bar left and right as fast as you can. Not only will you struggle to do this but you will carry so much momentum that once the weights on the end get moving, it will be hard to stop and rotate the other way. Now move that same weight really close to your wrist (which is still 50/50 but the weight is closer to the center of rotation) and rotate back and forward. You will quickly feel how much easier it is because the weight has only moved a few inches laterally while rotating vs the weight moving several feet when the weight is further out. This is why Mazda keeps moving these engines back as far as possible and one of the main reasons the Rx8 has such responsive steering and reflexes as most of the weight is with-in the front and rear tires.
I don't think it's made that big of a difference on this car. Yes a barbel would be extremely sensitive. The car is a different scale. It's not like he put 500lbs in front of the front wheels and behind the rear wheels. I bet it handles as well as any typical street FD, or better due to the suspension set up and corner balancing.
I'm really not too worried about it. I just have this feeling. The damn thing is like a time machine at 18psi. So whatever negatives we have with turning/nimbleness will be made up in corner exit / straightaway power. We're definitely anticipating understeer vs an OEM rx7
Finally getting around to putting the rear back together, liking these new spacers and aggressive stance
Not every blazing fast track car has the handling balance of an FD.
Plenty of absolute track weapon Subarus and Audis and they have the entire engine ~6" or so in front of the front axle (and all the associated handling issues).
Even some super/hyper cars are purposefully set-up for high speed stability at the expense of low speed handling balance.
Miata analogy is a good one; very few cars have the balance or nimbleness of whatever the newest Miata/MX5 is at the time, but there are many, many faster cars at the track than a Miata.
Now, proceeding to do front wheel studs, and install the plates,
Then onto the master cylinder brake booster delete. Upgrading to 0.81" manual master cylinder, PTFE Lines. Installing Big Brake Kit next week
Car goes back to fabricator in 3 weeks for new downpipe. Simple 5>4" side exit with titanium tip. This will be a track option "race" pipe, that i'll use to remove the full exhaust and cut out system to drop weight under the car/risk of fire out of the back, gain ground clearance, and will save probably 100lbs in weight. Before you say this is unsafe or not legal, it is. Road Atlanta and Barber do no have sound ordinance, and I've already contacted GTA about the side exit in the front fender. Its legal.
Un-muffled 4 rotor is gonna sound insane out there. May need to plan a trip for spectating purposes.
Gonna be loud with that there screamer pipe. Should probably just raise the boost so the wastegate doesn't have to dump as much instead of running mufflers. Ever.
worked my dick off last night, drilling into the tube core-support with a 90 degree drill. Upgraded the splitter rods on the corners to these direct rods straight to the core support. Going to come back and place 1/8" steel plate on the underside of the splitter to add surface/area load distribution for each rod attachment. Even now, its 10x more solid. I want to be able to not only stand on it, but stand on it and jump up and down.
To do:
-Waiting on ARP studs for the driver side. Then to final installation. Lock-tite all of the bolts for the two-piece hats, and bracket bolts.
-bleed brake system with Castrol SRF, highest boiling point out there, check for leaks/line quality
-wire up front ABS sensor to ECU for traction-control/ignition retard
-wire up LED strip lighting in underside of oil cooler duct opening to function as new DRL
-wire up single LED for blinker in bumper, between oil cooler opening and turn signal
-replace tie rod ends with bump steer adjustable ends to compensate for rumble strips (possibly)
-get car over to Walker Morgan for race track test pipe fabrication, so we can delete the cut-out/full exhaust system and save weight/heat, fender exit only
-corner-weight/ride height adjustment at race division
-alignment at race division
-get back on dyno to check tune/leaks/etc, turn boost down to 10psi (600hp) level for control/safety
-install fire suppression
-Import Alliance, End of March
-Switch to DTC70/60 pads, test run beginning of April, Barber Motorsports
-re-evaluate changes
-Prep for Global Time Attack, Road ATL May
Question is if I should add an accusump to the trunk
I've seen the finished product, but seeing this build thread just wins the prize man. Such dedicated and immaculate work. Great job, that thing must be a blast to drive.
Where did you pick up your splitter rods if you don't mind?
I'm working on my splitter now and haven't found anything local that looks like it would be long enough and strong enough. I like that you have spread yours out with four as well.
I've seen the finished product, but seeing this build thread just wins the prize man. Such dedicated and immaculate work. Great job, that thing must be a blast to drive.
-M
thank you, where did we meet in person? trying to recall plz help jog the memory
Where did you pick up your splitter rods if you don't mind?
I'm working on my splitter now and haven't found anything local that looks like it would be long enough and strong enough. I like that you have spread yours out with four as well.
thanks, i'm not sure exactly where. I've had these a long while, but i did order them on ebay or amazon or something. I wasn't to hard to find these, was just a basic google search and they just popped up!
So i've been side tracked this week with my day job, haven't had much chance to finish the car. However, I did pull the brakes back off and decided to remove all the dust boots after doing more road racing research. When you push brakes really far and hot, its almost a guarantee that the dust boots, which cover the pistons, will melt. This will leave residue/rubber on the back side of the pads and gum up the pistons. Since this car won't be seeing much daily driving time, there shouldn't be any issue with the boots removed. I was advised to just clean the pistons before depressing them when changing pads and all will be fine.
Reinstalling the brakes tonight, and finally bleeding the system with the SRF. Then we'll be doing a tape line around the car and working on ride height/corner weighting and alignment all weekend.
Also went ahead and picked up 1.5 quart accumulator which I'll be mounting in the hatch with a 10an feeding a sandwhich plate at the engine. Can't be too safe!
Doing some research on fire suppression systems. Still not sure exactly what's best, but i'm thinking 4 liter tank, passenger floor board, 2 nozzles ****-pit, 2 nozzles over the exhaust manifold downpipe area
Plan is to get all of this stuff sorted this weekend and next week. Leaving only Fire Suppression as the last thing to finish up. Then the car will go to Walker, the same fabricator who performed the equal length manifold. He'll be making a short 5 to 4 transition downpipe which will directly side exit. This will be a "track" pipe. So that I can ditch the cut out system and full exhaust, just for the race track. Should save about 70-80lbs and MAJOR heat reduction. The heat will no longer soak into the trans/tunnel passenger area, will no longer heat up the transmission pan, and less fire risk/burning wires/hoses/fuel at the rear of the car. This thing shoots dangerous fireballs, and for long periods. Can't risk that fire updrafting off the back of the car and melting the bumper. The air passing along side of the car should push away the side exit flames safely however.
Did you go with an electric valve for accumulator or the hand operated valve?
hand operated, as I only plan on using it when on track and pre-oiling when sitting for really long periods we'll shut it before killing engine for storing
hand operated, as I only plan on using it when on track and pre-oiling when sitting for really long periods we'll shut it before killing engine for storing
Gotcha, I'm planning on adding a 3 qt accusump along with a manual valve. The hard part is relocating the valve so that driver can easily access during startup/shutdown. I would like to stick the tank in the trunk somewhere as well. Curious to see where you place all that.
Gotcha, I'm planning on adding a 3 qt accusump along with a manual valve. The hard part is relocating the valve so that driver can easily access during startup/shutdown. I would like to stick the tank in the trunk somewhere as well. Curious to see where you place all that.
I do not believe it will be necessary to open/close the valve with each run. Only when sitting for very long periods of time, would it really be beneficial to have the "pre-oil" charge. I will likely just leave it open at all time.
If Abel is coming back out to test tune the car, please stress to him not to drive through lean spots in the map like he did the whole time he tuned the car the 1st time, it was ruthless to me and was pissing me off lol.
For race applications that are installing an Accusump to address a low oil pressure concern, the options are similar, but different. The same manual ball valve options mentioned above can be used in these oil pressure control situations. As before these valves are the simplest and most straight forward in operation and installation. However, unlike when being used for pre-oiling only, the simplicity of the manual valve limits its performance when protecting against oil pressure surges. Being totally open all the time the manual valve will discharge oil any time there is any drop in pressure. The valve makes no distinction between a small insignificant drop in pressure and the big drop in pressure that you put the unit in to protect against. That means you might reach that tight corner or deceleration zone with less pressure in the Accusump due to the unit discharging some of its oil before you got there.
For those that want the most protection, The EPC (Electric Pressure Control) Valve addresses this "premature discharge" by providing a "smart" valve that will hold the Accusump's max pressure until the moment you need it. In addition to increasing pressure drop protection, the EPC valve's "smart" operation ensures your Accusump will not discharge extra oil in the pan that may creating windage and causing parasitic power loss. Both of these situations make the EPC valve a must have for the track.
02-14-19, 03:46 PM
