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The sound, it's all about the sound. It's like a cross between a Superbike and an F1 car.
I don't even care about the turbo and how much power it makes. Being able to wind it out and hear that noise is what it's all about for me. It's what makes the price of admission worth it.
I'd feel the turbo would keep me from being able to go WOT as much as I'd want lol.
Yah that sound would turn the best of any motorhead head. The publicity lies with you, I know your not shooting for high hp eventhough you probably can't make less than 800hp on your lowest setting when tuned lol, but you should still show up at tx2k17 or any big event just to show it. I love Doritos and I want the world to here this very unique noise. Your car is worth a lot!!! Ur rich! Btw, I know you know but your super close to being a record holder.
This car is beautiful and it has been a pleasure to read through this whole build so far. After seeing pics and videos pop up on my facebook I'm glad I was able to find this!
Drove her last night to a car meet, just in love with her now finally. The only last bug to work out is some minor heat / cavitation w/ the fuel system. The rails just get so hot and overheat the return fuel into the surge tank causing cavitation. Probably need to tear the system back down, swain-tech coat the manifold, and then wrap it, then sleeve the fuel rails in the vulcan sleeves with holes drilled out for the injectors.
Also thinking about giving up one of the rear oil coolers (used for water) and running the fuel through it in the return line as we now have front mounted water cooler in addition to the circuit.
So definitely a good bit of work to do. Hopefully once we wrap this up in next few weeks, then we get nelson back out for the tune, and then Bryan Leonard will take it out to barbers for a few laps so we can try to break the first transmission Then onto PAR dog gear set or t56
Another little retake of the first vid by car throttle
The rails just get so hot and overheat the return fuel into the surge tank causing cavitation. Probably need to tear the system back down, swain-tech coat the manifold, and then wrap it, then sleeve the fuel rails in the vulcan sleeves with holes drilled out for the injectors.
I think you'd do really well with a heat shield. There's an ongoing thread about it for a different application, but the math looks really promising. And, it would compound well with your other options.
From: https://www.rx7club.com/race-car-tec...ld-out-574972/
Originally Posted by speedturn
"Is aluminum really a good heat shield since it radiates heat so much? Would it not just absorb heat from exhaust pipe and radiate that heat upward towards intake and floor?"
Heat transfer by radiation is proportional to the Temp of the source raised to the 4th power, minus the temp of the receiver raised to the 4th power. This is not a linear function; it is a very steep exponential function.
Lets assume you have exhaust pipes at 1600 F = 2040 Rankine
assume heat shield is 400 deg F = 860 deg Rankine
assume intake manifold is 120 deg F = 580 deg Rankine
Exhaust to the 4th is 17,310,000,000,000
heat shield to the 4th is 547,000,000,000
Intake manf to the 4th is 113,000,000,000
Okay now, the radiant heat transfer is proportional to the differences of those 4th powers.
Difference between header and heat shield is 16763000000000.
The difference between heat shield and intake is 434000000000.
Sooo the radiant heat transfer from the header to the heat shield is 39 times more than the radiant heat transfer from the heat shield to the intake manifold (this is neglecting surface area and surface finish.)
This is why heat shields are so important - they re-radiate out much less heat than they take in. The heat they do absorb is transferred via convection into the air flow passing by.
I love those up face screamer pipes!! Maybe not so great in the rain! but they look and sound the nuts! I want to go out in the garage and cut a hole in my bonnet now! Great work and so glad to see it finally come together as you wanted.
I think you'd do really well with a heat shield. There's an ongoing thread about it for a different application, but the math looks really promising. And, it would compound well with your other options.
From: https://www.rx7club.com/race-car-tec...ld-out-574972/
SpeedTurn is another Alabamian. He road races with me in SCCA and has a GT-3 1st gen rx7, NA 13B PP with a dog box that sounds amazing going through the gears. He actually had some issues with fuel heating and added a fuel cooler to fix it.
They offer straight-cut gears with input shafts / output shaft. Kinda of interesting....interesting thought to keep the stock trans / feel and build the f*ck out of it, basically the old school GURU dog box. Kyle Mohan offers a billet oil pan as well.
Mazzei, have you driven a car with dog rings before? (sorry if that is a stupid question, but i'm curious)
a good friend of mine in college had an LS1 swapped FC with a liberty gearset T56 with dog rings and helical gears. the dog engagement honestly wasnt bad, and the car could be driven nearly stock-style without much fuss. you simply get a very solid "CLUNK" when the castetops engage. he didn't have any kind of torque reduction system (like ignition cut) so he had to barely blip the clutch to remove some torque and he could no-lift shift and shift super fast. it was cool.
watch some of the PPG videos on youtube. they have some great "daily driver" videos showing how easy their dogboxes are to drive.
--you could setup flatshift ignition cut in your EMS and have a lot of fun no-lift shifting if your gearbox housing and gears can handle the torque; you could maybe use a simple switch on your shiftknob, or the top switch on the clutch pedal (for the oem cruise control disengagement), or maybe a gear position sensor if you get fancy.
now the straight cut gearset is a different story. absolutely do not get straight cut gears unless you're thrashing gearbox housings and shafts and you have no other choice; the whine that the gears create is so abnoxious (in my opinion) that you don't want it on anything other than an all-out racecar. i'm sure you've checked out logan's Defined videos of him driving his 4 rotor car around. i personally think straight cut gears ruin a street car, especially when it distracts you from the beautiful sound of a 4 rotor.
this is just my two cents; i'm curious how you repond on this one, as i feel like drivetrain (transmission, mostly) can make or break a car project (pun intended). this is also where people can drop LOTS of money on a single component (transmission) to get a good setup that can meet targets and expectations based on the purpose of the car.
Last edited by jacobcartmill; 02-15-17 at 12:02 PM.
the dog engagement is pretty awesome at full song, but would be a pain to live with on the street.
In the formula mazda I had once you got close to where you want to **** you just pre load the gear lever and slightly lift and it would go into gear effortlessly. Dog boxes require maintenance
With the regular 5th gear, I imagine with the torque of the 4 rotor you could skip from 2nd or 3rd to 5th with no real problem. So it might be livable on the street.
I would say its all a trade off, but for fks sake you already have a 4 rotor in a street car with a full cage, what left is there to compromise on?
Mazzei, have you driven a car with dog rings before? (sorry if that is a stupid question, but i'm curious)
a good friend of mine in college had an LS1 swapped FC with a liberty gearset T56 with dog rings and helical gears. the dog engagement honestly wasnt bad, and the car could be driven nearly stock-style without much fuss. you simply get a very solid "CLUNK" when the castetops engage. he didn't have any kind of torque reduction system (like ignition cut) so he had to barely blip the clutch to remove some torque and he could no-lift shift and shift super fast. it was cool.
watch some of the PPG videos on youtube. they have some great "daily driver" videos showing how easy their dogboxes are to drive.
--you could setup flatshift ignition cut in your EMS and have a lot of fun no-lift shifting if your gearbox housing and gears can handle the torque; you could maybe use a simple switch on your shiftknob, or the top switch on the clutch pedal (for the oem cruise control disengagement), or maybe a gear position sensor if you get fancy.
now the straight cut gearset is a different story. absolutely do not get straight cut gears unless you're thrashing gearbox housings and shafts and you have no other choice; the whine that the gears create is so abnoxious (in my opinion) that you don't want it on anything other than an all-out racecar. i'm sure you've checked out logan's Defined videos of him driving his 4 rotor car around. i personally think straight cut gears ruin a street car, especially when it distracts you from the beautiful sound of a 4 rotor.
this is just my two cents; i'm curious how you repond on this one, as i feel like drivetrain (transmission, mostly) can make or break a car project (pun intended). this is also where people can drop LOTS of money on a single component (transmission) to get a good setup that can meet targets and expectations based on the purpose of the car.
Hey jacob,
Hell yea, that sounds awesome. My buddy actually had a WRX with dogged, straight-cut gears. So he had the super loud whine, but also the no-lift shift ability. It is definitely a little tougher to drive in traffic. You have to bang them quick or you grind and wear out the trans quickly. Interestingly, this company PAR offers the straight-cut option in dog and synchromesh. The straight-cut is really the reason to upgrade, the load will be different on the gears, and less stress placed into the stock casing. There's not too many people who have done this to the OEM trans. There's been quite a few helical upgraded gear boxes from Liberty, but many have still stripped the gear teeth on 3rd. The straight cut is supposedly much stronger. Personally just really want to keep the PPF and stock feel of the car drivetrain yet kick of the engine. It makes it feel like the same car from the factory but with high doses of steroids, instead of feeling like something all-together different. Initially thought about t56, and then a sequential, but that just changes the point of the car in a way.
As far as the gearset whine, I absolutely love it! The louder the better!
the dog engagement is pretty awesome at full song, but would be a pain to live with on the street.
In the formula mazda I had once you got close to where you want to **** you just pre load the gear lever and slightly lift and it would go into gear effortlessly. Dog boxes require maintenance
With the regular 5th gear, I imagine with the torque of the 4 rotor you could skip from 2nd or 3rd to 5th with no real problem. So it might be livable on the street.
I would say its all a trade off, but for fks sake you already have a 4 rotor in a street car with a full cage, what left is there to compromise on?
The extent to which this car braps, both in sound and the entire drivetrain lol it might as well be as comfortable as driving a square wheeled wagon at this point lolol so no worries to comfort or drive-ability, pure chaos is all that matters lol
So in that case, hell yea it sounds awesome. The no-lift shift sounds incredible!~
yeah, the straight angle of the gears removes that side-to-side (or front-to-back, depending on how you're looking at it) force from the gears and reduces a lot of stress from the mounting points of the gears and bearings (mostly the housing). the side effect is that the gear whine resonates and is much, much louder.
hey, to each his own. maybe i'm getting old
anyway, we can all agree that clutchless no-lift shifting is very cool.
yeah, the straight angle of the gears removes that side-to-side (or front-to-back, depending on how you're looking at it) force from the gears and reduces a lot of stress from the mounting points of the gears and bearings (mostly the housing). the side effect is that the gear whine resonates and is much, much louder.
hey, to each his own. maybe i'm getting old
anyway, we can all agree that clutchless no-lift shifting is very cool.
bingo thats exactly what the company rep explained! They don't really have a torque rating and suggest a full-sequential aftermarket transmission for the power level if you wanted a gaurentee but have said that 500 ftlbs of torque has been proven in brutal abuse historically. Its kind of a toss-up
It seems the two common most problems we see w/ stock trans are:
1. 3rd gear stripped
2. input shaft sheering
One of my buddies Aaron, has gone through at least 10 stock transmissions, and he reports that before the 3rd gear explodes, he always notices bearing whine. He's pulled one early and found that the input shaft bearing becomes playful right. So he believes that the side-to-side forces of the helical gears flex the case / shafts / bearings, basically spreading apart the clearances until the gears eventually stress/misalign and let go.
So the golden question is what kind of abuse could a stock box hold if you straight-cut her, put a stronger input shaft and counter shaft, billet shift fork, and a fat oil pan sounds exciting to test, although would absolutely suck to destroy after all the expense
One cool thing is the gear set is offered with synchros. So because it see's street use, and potential future buyer maybe not want to learn how to bang a dog box, im leaning towards synchronized straight cut set
Liberty transmission could comment on the limits of the stock format. They build out the stock box up to and past recommended street applications.
I believe thewird had some experience there? https://www.rx7club.com/canadian-for...010240/page11/
OCD wont let me not mention that ppl are also starting to look into the 350z transmissions. Though I don't have a fun link for it. Can't remember if there is an adaptor readily available...
02-11-17, 04:54 PM
Then onto PAR dog gear set or t56
sounds exciting to test, although would absolutely suck to destroy after all the expense