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-   -   plan on building 20b FD (https://www.rx7club.com/race-car-tech-103/plan-building-20b-fd-838958/)

1SxyRXy 05-11-09 02:38 AM

plan on building 20b FD
 
well i sold my FC a long time ago.. when i was like 19 or something. i am now 23, i drive a sc300 with a supra engine in it. i was going to turn my sc300 into a track car. but i decided against that when i saw how low the prices are for a FD. so my plan is to put a 20B. but i dont know if to go NA or turbo. i like the hassle free of NA but then you get alot less power. who does p port now these days. i havnt been around the rotary scene in a while. what league and im looking to be in NA? i have no idea what the power would be like. if NA then i would go with S5 NA internals.. correct?. who has some input or links to some 3 rotor track cars. what kind of compression ratio am i looking at with S5 NA rotors? of course if i go to turbo, i will ditch the twins. what do most guys run for engine managment?

wrankin 05-11-09 08:10 AM

Firstoff - no disrespect intented but you come across as someone who has no knowledge of what they want nor what it's going to cost to do it. You don't appear to have any idea about the power levels of the different engines, of the difference between racing and just track driving or even what racing organizations and classs you can be considering. You are not likely to be taken seriously by anyone until you do your homework.

Do a little search for BigAl or Rob20b and look at their setups.

But here is the bottom line - if you are considering a 20B setup, the cost of the FD itself represents a small fraction of the total cost of development of the car.

My advice? Go do some track days in your SC300. Talk to your local racing organizatioons (NASA and SCCA). Go to some races. Read Dave Gran's book (search for the name in this forum). Then decide if you want to race and decide on a car and a class.

Good luck,

-b

gracer7-rx7 05-11-09 10:59 AM

+1

Chaotic_FC 05-11-09 03:58 PM

If you really are about to go 20b then you need to think about what kind of power you're looking to make.
a p-port NA 20b could make 400rwhp-ish.
turbo 20bs could make the hell of a lot more power, depending on what you do to them.
look into engine management like haltech E11v2, motec M880, Autronic Sm4... to name a few good choices.
also, what is your budget here? are you building this yourself?

1SxyRXy 05-12-09 10:22 PM

figured i would come of acting like i dont know anything. i mainly love the way the N/A 3 rotor sounds. p port is probably out of the question. i just want to have a weekend race car, that i can take the track and have fun. i do have alot of knowledge about rotory engines and how much it is going to cost me. i know it isnt going to be cheap, i dont want an insane amount of horse power. i guess a safe amount would be 500hp. i know its going to be exspensive, building any track car isnt going to be cheap. i dont want to go with the FC again. im also not planning on building this car in a couple months. but basically i guess i was looking for some 20b guys that track their cars. thanks for the help. i was going to probably send the engine to rotary ressurection for a rebuild. neither of those user names worked on here. i will be doing all my work, im going to build the car from the ground up. i am very capable in doing my own wiring and tuning and what have you.

Chaotic_FC 05-13-09 02:35 AM

if you're looking for 500 flywheel hp than a p-port 20b is perfect.
its not as expensive to do a p-port as you'd think.

wrankin 05-13-09 10:55 AM

Okay, so you just want a track car - something to do some lapping days in. That's cool - many of us have done that (including myself). So here are a couple pointers, just things to think about.

1) Novice and beginner (and some intermediate) drivers should not drive cars with lots of HP. It just hides your mistakes. Yeah it's fun to rocket down the straights with 500HP, but what are you learning? Start small and build up the driver as you build up the car.

2) Buy your first race car, build your second. Already built and sorted cars sell for roughly 50 cents on the dollar compared to what it costs to build them. There are lots of track-ready FDs out there if you look around and are patient. Start out with something near stock and running. It gets you on the track more quickly. Build that monster P-P 20B on the side as you have the time and money.

2b) (corollary) If and when you go to sell your track car, you'll be amazed at how much it doesn't sell for, compared to how much you spent on it.

3) Safety equipment should be at the top of your expense list. As your skill increases, your speeds increase and your chance for an "oh sh*t" moment increases. Roll bar/cage, harnesses&seats, helmet, HANS, suit, etc. should all be on the list.

4) Spend more on the driver than you do the car. Seat time with a good instructor will make you a better driver. Car mods make you only marginally faster, but never better.

5) Don't forget the consumables in your budget - tires, pads, rotors, gas, all fluids, hoses, wheel bearings, transmissions... It adds up quickly (eg. you start running big sticky rubber at $1k++/set, and it's not going to last for many weekends)

6) Don't forget to budget for track fees, hotels, food.

...and one more

7) Don't forget to have fun out there!


Good luck,

-b

Beast From The East 05-13-09 06:46 PM

Listen to Bill
 
Just ordered tires for my track beast - BFG R1s - total bill, 1K.

Just got back from two days of HPDE:

Food - $40
Gas for Truck - $80
Gas for Car - $200
Track Fees - $300
Prepping car for track (fresh oil, brake fluid, etc) - another $50.
12 pack of Heineken to the shop I have do early tech on the car so I don't have to do it at the track - $12
Camping gear to save money by staying at the track - $100 (one time only expense)

So, just for a plain old track weekend, not counting wear and tear, it's a $700 affair.....

Oh, yea, cost to put together FD with all the goodies - $60k+, don't want to add up all the receipts. Still needs another 10K for safety equipment like cage, webbing, seat, HANS, fire suppresion system, and fuel cell. <sigh> and I borrow my trailer, need another 4 to 8k for the trailer I want.

Get the picture? There's no substitute for cubic dollars. Speed costs money - how fast do you want to go? How do you make a small fortune in racing??? Start with a large one.

Beast

Racing is life - RIP Steve McQueen.

OneRotor 05-13-09 07:28 PM


Originally Posted by gmonsen (Post 9206258)
1SxyRxy... NA 20b's are making 415-475 whp with p-ports. Low end uses S5 low compression rotors and high end uses Rx8 rotors. Need ITB's as well. Mine is making 360+ without p-ports or ITB's and I think we will get over 375 this weekend. Would make a great race motor, because its so linear.

Gordon

How much do you have into your car Gordon? ;-)

Also look at David Hayes's build in the FD section. He has well over 100k into his car.

Everything that has been said above is a good indication of what you're looking at if you want to build a 20b track FD. If you go with a P-port with all the goodies (that includes carbon seals for high rpm running), you're looking at a rebuild every couple of seasons. Good luck with the build.

Gene 05-13-09 09:01 PM


Originally Posted by Beast From The East (Post 9206181)
Just ordered tires for my track beast - BFG R1s - total bill, 1K.

Just got back from two days of HPDE:

Food - $40
Gas for Truck - $80
Gas for Car - $200
Track Fees - $300
Prepping car for track (fresh oil, brake fluid, etc) - another $50.
12 pack of Heineken to the shop I have do early tech on the car so I don't have to do it at the track - $12
Camping gear to save money by staying at the track - $100 (one time only expense)

So, just for a plain old track weekend, not counting wear and tear, it's a $700 affair.....

Oh, yea, cost to put together FD with all the goodies - $60k+, don't want to add up all the receipts. Still needs another 10K for safety equipment like cage, webbing, seat, HANS, fire suppresion system, and fuel cell. <sigh> and I borrow my trailer, need another 4 to 8k for the trailer I want.

Get the picture? There's no substitute for cubic dollars. Speed costs money - how fast do you want to go? How do you make a small fortune in racing??? Start with a large one.

Beast

Racing is life - RIP Steve McQueen.

Trailers can be had for real cheap nowadays if you're patient.

http://www.racingjunk.com/

I really like the BFGs on my track FC, though I'm considering going to something like a Falken Azenis or a Dunlop Direzza to save money and get back to basics to work on my skills... the BFGs are awesome and all but I feel like they hide my mistakes.

BASTARD 05-13-09 09:14 PM


Originally Posted by whitey85mtu (Post 9206284)
Also look at David Hayes's build in the FD section. He has well over 100k into his car.

please put that into context before just letting it spew from your lips:icon_no2:

jamespond24 05-13-09 09:23 PM

hwnd has the whole crossmember and whole 20b for FD forsale.

1SxyRXy 05-14-09 01:02 AM

thanks for the information guys, i didnt mean to come off sounding like a dumbass ricer or whaterver. i want to build tin he car my self. more pride in that. i helped my friend with a LS6 in his FD, i like it alot but i want to do rotary. i guess i can start off with the 13b on twins in no SEQ, cage, pads, tires, ect. my plan is to start building this after my wedding in oct and i should be moving into a house with a 2 car garage. but i have to build my corrado first. for a DD

wrankin 05-14-09 12:21 PM


Originally Posted by Gene (Post 9206579)
Trailers can be had for real cheap nowadays if you're patient.
http://www.racingjunk.com/

D*mnit, Gene. *Why* did you post that link?!!!

I will not click on it.
I will not click on it.
I will not click on it.
<*click*>

Crap, there goes my budget.

:D


I really like the BFGs on my track FC, though I'm considering going to something like a Falken Azenis or a Dunlop Direzza to save money and get back to basics to work on my skills... the BFGs are awesome and all but I feel like they hide my mistakes.
Very good point. I was going to add that as a corollary to my "avoid high HP" suggestion. Street-ish tired give so much more feed-back. I remember when I was tracking the FD and actually started listening to what the tires were telling me. It was definitely one of those "Eureka" moments. I'm currently running shaved RA1's and while I love the grip I do miss the talking. :)

-b

Gene 05-14-09 12:34 PM


Originally Posted by wrankin (Post 9208316)
D*mnit, Gene. *Why* did you post that link?!!!

I will not click on it.
I will not click on it.
I will not click on it.
<*click*>

Crap, there goes my budget.

:D


Very good point. I was going to add that as a corollary to my "avoid high HP" suggestion. Street-ish tired give so much more feed-back. I remember when I was tracking the FD and actually started listening to what the tires were telling me. It was definitely one of those "Eureka" moments. I'm currently running shaved RA1's and while I love the grip I do miss the talking. :)

-b

I do have manual steering though, which is pretty talkative itself :)

Beast From The East 05-14-09 07:28 PM

Gene, I check that site every once in a while - since I can still borrow a trailer right now I'm not eager to get one (you know the story about buying the milk vs. the cow) , but if the right opportunity comes along I will jump on it.

Now, Bill and Gene, I'm moving off of old Toyo T-1S's that have zero grip anymore. What the tires tell me is - do you like to drift,? 'cause we're not going to give your 400 rwhp any grip at all. They are so rock hard they don't even really make noise when they slide, very little feedback actually. a 6 inch rear-end step out on a high speed apex is pretty exciting. So, I decided to step up....but you are right about how good tires will mask bad habits. My father is running 3rd in points for TTR in the AZ NASA region and he also feels that tires are allowing him to get away with bad habits....I just can't see spending $800 on a 100 to 200 treadwear tire when for 1K I get 40 :)

Gene 05-14-09 09:53 PM

I'm not racing, just doing DE. The BFG-R1 tires are phenomenal though, they're supposedly as fast as hoosiers and they wear much better. I think you'll be happy with them.

BTW, an interesting thing about them... I was tuning my air pressure by using a probe pyrometer and getting the temps to average across the tire. They would warm up immediately and had huge grip that way but halfway to 2/3rds of the way through a 25 minute DE session they would totally go off and the car would handle like crap. A guy at an event I was at was running the same tires and he said he had talked to BFG and they told him to run 41PSI hot rather than using the pyrometer. I tried this and found that they would take a little longer to warm up, and wouldn't have quite as much ultimate grip, they would stay consistent for the whole session.

Beast From The East 05-15-09 05:36 PM

Wow, 40 psi is a lot
 
That is great info, and you can bet will will look at that at Infineon next month. Do the BFGs want the same temp inside and out, or do you want a bit warmer (say 10 deg) on the inside, as Howard Coleman suggests in his masterpiece thread on FD suspension set up?

Also, are you running straight air or nitrogen? I have created a nitrogen charging system for my AD coil overs (dill chuck, line, pressure regulator, and a 40lb bottle of nitrogen) and had planned on using nitrogen on these tires to help deal with rising psi as the tires heat up.....

Oh, and what psi were you running when you were getting the fall off toward the end of the session, before going to 41psi?

Oh, and I went to the BFG site and found this:

http://www.bfgoodrichtires.com/asset...ne_2.26.07.pdf

Gene 05-15-09 08:00 PM

Straight air.

I wish I kept better records of this stuff... IIRC to get them to 41 hot I start them at 32ish... I had been starting them at maybe 27 or 28 to get the center to be the average of the inside and outside. I run quite a bit of camber, -2.5F and -1.5R. I forget how the temps came out though.


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