fd3s400438

Hello to everybody...

I have a track prepared FD and I recently did my first drag event...I did not prepare the car for drag racing and I left it as it was for the track. All I changed was the wheel alignment ( 0 camber , 0 toe ) and with used track day tyres managed a 12.5 with 0-62ft @ 2.3 and 120mph

The car is only running 420bhp and I liked the event so much that I want to convert the car slowly and steadily for drag racing but not spoil the every day ride

I have to main areas to address

1) MORE POWER
2) TYRE and SUSPENSION SETUP


I will write my thoughts and would like to hear from all of you with far more experience

I would like to state that we do not have a proper drag strip and we only use glue for the first 30-40 ft max... The rest is normal highway tarmac

1) Power

I curently have a small T04E by hks producing no more than 420 bhp engine. My next step is the TDX61 which will give me about 520bhp@20psi
I will also use a fuelling upgrade with 1680s'' , fuel pump , fuel reg etc to make sure power is fed properly. I already have all the rest ( intercooler , alum water rad , twin plate etc to support the power


2) Tyre and suspension setup


Here I am walking blind. I thought of using a set of MT ET street radials 275/40/17 or ET street 26/10.5/16 on oem 16s''

Because the prop shafts , drive shaft and rear diff are all OEM standard parts I am not sure about the ET streets...Maybe TOO much grip for OEM tranny

My suspension is a basik D2 coilover ( height adj and 36 clicks from soft to hard )
I noticed that at the current height ( 25 inch rear and 25 inch front from ground to fender ) and with the rear coilovers set to the softest setting the car felt TOO stiff and the wheel spin in first and second gear was TOO much

Tyres used at the rear where TOYOS R888 size 255/40/17 @ 15-18psi that did not work at all

So your thoughts on power , tyres + wheels , suspension and ride height setup and any other advise

My target is a 1.8 0-62ft with a 11.5 quartel mile


On this pass I over took the other car 100m before the finish doing a 12.5 with 120mph and 0.62ft@2.3 . I think that the car is sliding and wheel spinning all the way through 1st AND 2nd gear


On the second vid you can the same pass at 3minutes 20 secs and my second pass at 8 minutes and 45secs.

The second pass was a disaster because I stalled the lanch and did a 13.1 with 2.8 0-62ft with the same exit speed ( 120mph )

My current weight is 2530lbs + 220 lbs ( myself )

Thanks for your time and input

bigdv519

iTrader: (3)

Although I don't see the exact problem with your launch, there def seems to be a problem there. You have the power and speed for a high 11 second pass, but your launch is holding you back. It could be your components or your technique. A technique I used a few years ago (18" rims, street tires, same weight, ~330rwhp) was slipping the clutch out of the hole. I would get the revs up to about 5k rpms, then easy off the clutch while going full throttle. I was inconsistent, but managed a 1.9 60'.

Good luck and I look forward to seeing your times improve.

my .02 (I'm no expert).

Montego

iTrader: (1)

IMO you should hold out on increasing the power until you figure out why you netted a 12.5 when your trap speed is 120MHP. If you go by comparison, people with similar trap speeds are about a whole second faster than you.

Fast Mazda RX-7s 1/4 Mile 0-60 Drag Racing - DragTimes.com

Check out Brook's time (yeah dude could drive).

362 RWHP
1/4 Mile ET: 11.425
1/4 Mile MPH: 120.350
1/8 Mile ET: 7.338
1/8 Mile MPH: 95.790
0-60 Foot ET: 1.665


http://www.dragtimes.com/Mazda-RX-7-Timeslip-19.html

fd3s400438

My dear friends

As you so wisely say if with only 340 bhp wheel I have a 2.3 62ft imagine how much worse it will be if I built up more power...

How can I improve my first 100ft. What type of rear suspension do I need to use ??? What ride height adjustments do I need to address ???

I will choose either ET street radials 275/40/17 or ET street 26/10.5/16 . But I still need your help regarding basic suspension and ride height setup and any other tricks I might be missing

What suspension do you use. How do you set it up front and rear. What else can I change to improve the 1/4 mile with my power left unchanged

Thanks alot

Montego

iTrader: (1)

I am not knowledgeable on what equipment is best but several people on this site are. You should pm ErnieT he is a moderator here and I am sure he will be happy to give you pointers.

RX7Club.com - View Profile: ErnieT

Holton713BRE

iTrader: (4)

I've gone 1.6 in the 60ft with a 235/60-15 Goodyear radial, on a stock wheel and trapped a 1/4 mile time of 12.6 at 112 mph. I did that on rough guess, of maybe 320hp. Launch technique is a must along with tire set up.

Bacon

iTrader: (12)

Ernie shmernie, he never 60' like this
https://www.rx7club.com/showthread.p...2#post11256412

Montego

iTrader: (1)

^^ lol Awesome!

fd3s400438,

You owe Mr. Bacon a beer

fd3s400438

Ok now we are COOKING!!!

Is it tokico Illumina or HTS or does it not matter ???

fd3s400438

Had a look on ebay and found a set of 4 tokico so probably I will get only the rear...

Had a look for eicach prokit springs and only found for the FC or RX8

Where can I find these springs???

Thanks

Bacon

iTrader: (12)

For those of you who don’t know Ernie’s my boy so I can post stuff like that, LMAO
But ill reply to you PM here with my experiences and breakdown of my setup,
This is not gospel, nor do I preach it to be, it works and the 20+ 1.3 60’s I have are proof
SO the Key to the launch or 60’ as us racers refer to, is proper weight transfer, and application of power to the ground. The mazda IRS does a great job all around but wasn’t purpose built to drag race, there’s some key parts that make it usable, but not the answer
So weight transfer, some guys do it with stock shock/spring I went with the prokit b/c way back Ari was running them, and I liked the stance, soft on the compression of the shock, with less reound (dosent bounce you out of the squat) for your setup you want it a bit softer than stock, sounds like yours are 2 hard
Also factory bushing were rubber for a nice happy ride, solid bushings eliminate the flex on a hard launch, and the solid trailing arms and toe links, keep the suspension setting dialed in on a hard launch
The pumpkin aka the rear differential housing, can split open on a real hard launch, the pinion walks down the gear ring and opens the case like a chocolate covered cherry, and your day and wallet are ruined lol solution = PFS diff girdle, PF Supercars
Axles, the center axle bar are notoriously the weak part, pretty sure mike has been killing it on stock ones so…… but I have just the center section upgrade from DSS The Driveshaft Shop | Home page
They also make a pro level kit, with upgraded inner axle cups, also known as green cups, the factory Mazda ones were green, I’ve broken about 6 of these until I installed the TFC
Tfc= tilton flow control valve, Tilton Engineering - Innovative, High-Quality Racing Products a valve the flows 100% to release then has a restrictor orifice to slowly release the clutch. AKA slip the clutch, basically makes a bad driver good and also makes the slip easy and re peatable, personally I would go with the clutchmasters version if I was to do it again, but that’s just for ease of adjustment..
2 step is a way to leave the line @ a set RPM, while creating a load on the engine to actually build a bit of boost so the big ol turbo spools right up… really its using a external ignition limiter to limit the rpm, while the computer still dumping in fuel to try to raise the RPM, can be accomplished a few different ways, search 2 step on there, think there’s 2-3 good threads with everything you need to know about it and which parts to buy and all. Sure can you hold your rpm @ 7,500 by foot, but its sure nicer to just hold your right foot on the floor and leave like a beast when you dump the clutch….
Its all about keeping variables the same and changing one thing at a time, 2 many times I’m at the track and these knuckle heads and changing tire pressure, rpm, and how fast they slip the clutch… the more your track all your variables, and see how different adjustments affect your #’s then you can “dial” your setup in.

Enough about the parts, everyone’s setup varies, and there’s quite a few on here who do it with NONE of the above, so like I started out saying, its what works for me
Burnout is a big thing, everone varies their technique a bit, but I like 2nd gear, as I roll through the water box im in 1st gear, spin them real quick (like 2-3 revolutions) as I roll through , then let them pull you right out of the box, apply your line lock, and wait sitting in 2nd, when they signal you bring the revs up to 7k is and dump the clutch, hold the line lock and keep the rpm consistant till it starts to drop on its own, it also feels like theres “marbles” under the tires, tough to explain but youll feel it once your there. First butnout of the night always longer and harder. Then as soon as im happy with the burn or they signal you out I give it some more gass, and roll forward still burning about 5-6 feet, then clutch in, on the brak and roll up to the prestage.

The stickier the tire the more you need to slip the clutch and avoid drive line shock, shock is that kills axles, axle cups, 3rd gear…. And also breaks the tires loose and kills your ET
Remember ET how fast you got from point a- b, 60’ how fast you shift. Wheel spin all affect this..
MPH= hP, MPH dosent lie
Hope this helps,
Len

fd3s400438

ΟΥΑΟΥ!!!! Ι never believed that an outsider like myself would get so much info from you guys...
I know that these setups may be heavily guarded secrets...Despite that you gave me exactly what I need to know to setup my FD

THANK YOU VERY MUCH...If you ever find yourselves on holiday in Corfu email me and I will buy you not one but a full case of beers!!!!

Bacon

iTrader: (12)

Many have shared their knowledge And experiences with me, I share what I learn and what works/dosent work for me
Secretes are for the Honda guys

bigdv519

iTrader: (3)

Whats your paypal bacon so we can send you some beer money!!

Thanks man. Even though I knew a little bit of what you posted, it's good to hear it from someone else and even some theory behind why racers do the things they do.

fd3s400438

Nice to know that my questions helped other members as well. We have a second FD ( strongest maybe in Europe??? ) that with his old setup made 840 bhp crank but his 1/4 setup was not good

We will follow the same setup and hopefully he will do a low 10 , maybe a high 9 . His trap speed is over 140mph...


That was his accel from 60mph to 150mph


This is xxx rated !!!!

fd3s400438

Dear Bacon

Because I dont have a rolling road to measure my engines aqqurate BHP , with 120mph exit speed what bhp do you think my RX7 is running . Can you give a rough estimate???

Thanks alot

I dont know is it matter but on the race day I had a full tank so 220lb my weight + 2684 FD weight so 2900lbs total

bigdv519

iTrader: (3)

I would say right around 375rwhp.

fd3s400438

I believe you get the point even if the writting is in Greek LOL

Bacon

iTrader: (12)

Quick glimpse says 400ish

http://www.wallaceracing.com/Calculators.htm

jdr821

iTrader: (1)

nice Info Bacon. I needed all that info!!!! thanks.

fd3s400438

Does anyone know what 2 step I can use ( is any ) with an Apexi power FC ecu and OEM ignition amp

Do I need a better ECU to support a 2 step.

Can you please help cause I have no previous experience with 2 step ( make , install etc )

Always on a Mazda FD

fd3s400438

I read some threads and came across this on ebay...

Will this work with our ignition and is it any good ???

Thanks alot

MSD Ignition 6421 Digital 6AL-2 Ignition Control With 2 Step Rev Control | eBay

Bacon

iTrader: (12)

Yup, replaces the old 6AL, with a 2 step box
You will also need 2 bosh 5 pin relays
Basically the msd will be a ignition amp for your leading ignition, and give you a "switchable" lower rpm limit while having a static high rev limit... The relays will give you the ability to wire it up to the clutch switch to activate the step, then have it disengage right after launch... It will also be wired to turn off the trailings, to increase the unburnt fuel and also not let the rev continue to rise(the step would only be controlling the leading) if you search 2 step in this section and I think the single turbo section there's a few good threads...

fd3s400438

Ι know its off topic but I just came across this!!!!

WHAT THE F@@@@CK!!!!!

fd3s400438

Αs a friend pointed out on idle it sounds exactly like a big v6 two stroke boat engine. Compare the two sounds on idle...