trinirx

The front of my Fd feels pretty loose and pulls to the side alot on anything but perfectly smooth road. I am running stock shocks with apexi springs and otherwise stock suspension with megan racing toe links. Could it be bad front bushings causing this?

fd3s400438

My friend it could be a combination of many things. The first thing is massive difference in tyre pressure. Then tyre wear. Then wheel alignment. Then it could be something wrong with the suspension parts due to a massive pot hole or bump. I dont think its a buch. To check if it is a bush you could lift the car up and try to move the front wheels front - back - up and down by hand

This will show you if there is play that can be caused by a wheel bearing or play in the double wish bone setup ( usually bush )

It takes though a skilled mechanic in order to draw conclusion. My advise .... Check your ture pressure ( free ) and then visit a local alignment shop ( here in Greece it costs about 50 dollars to check and align both front and rear wheels )

Howard Coleman

iTrader: (6)

very on the money post from fd3s....

when you do get your car re-aligned make certain that they set tire pressure at 30 psi front, 27 rear and then check that the ride height is equal side to side. (since you have diff springs). differing ride height changes camber which will cause the car to not run true.

have the shop set the car as follows:

camber

front neg 1.2 degrees
rear neg 1.2 degrees

toe

front toed in just under 1/8th inch
rear zero toe.

castor equal minimal

zero thrust angle

ask for a printed copy of the final alignment specs. the FD is really easy to align.

let us know what you find. alignment should be an annual affair at minimum.

good luck,

howard

Howard Coleman

iTrader: (6)

just posted this in another thread and i don't believe i have provided this info previously so here it is...


Bump Steer.... Toe Steer

EVIL

while all suspension settings are important toe may be the most important.

at ride height a small amount of toe in forms a vector keeping the car driving straight.

on the FD there are three primary suspension components w re to toe...

upper A arm
lower A arm
steering arm

assuming the bushings in the steering arms and the outer ball joints are solid, generally a good assumption, the steering arm maintains toe dynamically. to do this it must trace the same arc as the control arms. any deviation and you get toe in or toe out.

it is essential to roll the tires thru a corner rather than drag/scrub them as they lose adhesion and self steer independently from each other.

i drove a friend's recently purchased FD 20B a few years ago.

100 yards.

i turned around and headed back to the garage. the car was just horrible to drive. i later did a plumb bob on it and found it had over 1/2 inch of toe steer at 2 inches! that means on a left hand corner the right hand wheel would trace an arc much tighter than the left hand wheel.

the result was on any turn you would have to counter steer out of the turn partially to get the car from going progressively tighter into the corner. the effect on traction was major since both tires were scrubbing, not rolling.

further, driving straight on a slightly bumpy road (most roads) as one wheel would encounter a bump and the tire would rise the corner of the car would self steer.

hunt.

relocated steering racks and relocated outer steering arm points are generally a band-aid and often do not provide the proper fix.

i personally would never touch the FD rack.

but that's just me.

howard

trinirx

thanks a lot...I will align with new front tires and see if that helps

Tem120

iTrader: (5)

Do a full alignment , and use the alignment advice that was given by howard to start with .

dont get bullied into getting the stock alignment!

Tem120

iTrader: (5)

I have a question regarding toe , I know toe in is done so the car is more stable on the highways and such on a stock car , but toe out gives more response .

When I aligned my car ( before I read this thread ) I chose 0 toe in the front . I figured it would be the best to give me quick response and I could live with the car being a bit more twitchy on the highway

My previous car a miata had some toe out . and I made it go straight LOL . but it destroyed tires.

So Howard I see you recommend a little bit of toe in May I ask is this to make the car easier to drive? or is there a certain benefit to it that I dont know about ?

Howard Coleman

iTrader: (6)

toe is set at rest. when the car is in motion toe in moves toward zero. "moves toward" is not zero but close. close to zero dynamically is good.

as to toe out and "response"...

i would consider "response" as always having to respond to the fact the wheels are trying to go their separate ways and you have to respond... you are mainly running on one wheel, then shifting to the other and having to change the steering to maintain a constant turn or attitude.

if you check toe out tires w a pyrometer you will find lots of scrub heat, as in "destroyed."

alignment is so important for track performance. you want the car to take a constant arc thru a corner and ideally never change the wheel from the initial set. this will never happen w toe out.

roll thru the corner = fast
scrub thru the corner = slow

hc

Scrodes

Quick question - I searched but I didn't find the answer


Seeing as the Eibach Pro kit is no longer in production and getting harder to find - which of the currently available springsets is the closest? From what I've seen, it looks like Racing Beat, but their spring rates are pretty damn close to stock.

poop2003

i searched for something as close as possible to eibach too and found that the RSR springs are not too far off

eibach
F 350lb/in
R 255lb/in

RSR
F 348.6lb/in
R 260.9lb/in

Howard Coleman

iTrader: (6)

good to know poop2003, they look fine.

howard

True_Talk_Snake

iTrader: (3)

wow i have to try this, but isnt the wheel size a bit to big?

Rotors R Cool

After over a year of my car practically sitting, I've decided to get back to it. I caught up on and reviewed this thread but was unable to find anything in relation to part numbers for the correct 8/6 springs for a Tein Super Street setup. Haven't purchased the kit yet because I want to make sure I can get the right springs.

Does anyone know the part numbers for Tein 8/6 springs or usable Eibach's? Due to the drop in spring rate from 12/10 to 8/6, will I need longer springs for the rear?

Thanks,

ambar.kulkarni

I am in the same boat.. Could pls someone confirm that this is the part-number.
it does say 7.8 / 5.8 almost 8/6 that Howard suggests.

SKM50-AUB00
http://www.tein.com/products/s_tech_price_list.htm

Howard Coleman

iTrader: (6)

Rotary works was supposed to have 8/6 by now.... you might check w them. i tried the Tein 7.8/5.8 link and it didn't work.... if they do have them that would look good to me. also Pettit may have them if you check via tel.

hc

Rotors R Cool

Quick update. Decided to just go with the Street Flex setup. Ordered 8/6 springs and stepped up an inch in rear spring length. Hopefully, the longer spring won't be too long. I remembered that somewhere I saw someone was having trouble with the 175mm springs in the rear.

Ordered a powerflex bushing kit for the rear arms and shock mount. Six pillowballs are going in as well. Also picked up a Pineapple Racing BT idler pulley kit to fix my waterpump slip and a Banzai trans brace for the lols. Hoping the gear whine isn't too bad. At this point, the sound system could come out and I wouldn't care. Last time I tried, I couldn't hear anything over the sound of how awesome this car is.

fd3s400438

I have a question that has been bothering me for a while now . I know that some nice spring setups for the Fd is something like 8/6 or 10/8 etc etc . My D2 coilover for example is 9.8/6.5

After viewing some Touge - Tsukuba fd setups I saw many FD's produced by famous tuners ( Re Amemiya etc ) running some funny number like 15/14 kg , 18/18 kg etc

Even if the track setup was justifiable , the Touge run is like a mountain public road . How can you drive an Fd on a road with track day tyres ( not full slicks ) with 18kg springs ?????

Rotors R Cool

Some of those cars are indeed aero cars however, while on the touge, they don't get fast enough to use it. To be honest, those cars aren't setup right for the touge. Those spring rates are far too high for that type of driving.

8/6 would probably be too soft for that kind of track use. The 8/6 setup is simply a nice street setup that can be used on most actual tracks. The touge is a very rough track and while it does need stiffer springs, 18/18 is F-ing stupid. 18/18 would work on a long high speed track with a large aero car, not a medium speed touge with bumps.

juha kankoulen

The re-amemiya cars most of the times use 16front -18 rear. Bare in mind that they have adjustable (blade) front sway bars and STOCK rear...... so it's logical to use such high rear rates, to get it to be somewhat equivalent to the front which has both springs and sway bar. Even in slow speeds (like 80 miles or something) there should be some load by the huge wing they use ......

Also bare in mind that Apexi N1 coilovers come with 14 spring rates. Supposedly a dual purpose coilover and not a pure track one.....it's not THAT harsh a ride actually.......
And even if the "touge" is supposed to be a street course (it's a bicycle course actually) I bet the pavement is way more even than the "tracks" whe have in our home country.

You can also watch this video and see that the Re-amemiya car has some (very minor of course) degree of body-roll (even with this rates)


As for the real track cars....the yellow panspeed fd has 21 rates or something

Bottom line.....I think it's their cars and their track so they know best.

fd3s400438

To be honest I think there is a fine line between what is '' race preped '' and what feels safe fore us every day drivers

My last visit to our Greek track produced a time which was close to the road car record... Without slicks that is ... Still the car felt very safe , I did not require any opposite lock etc etc . Yes there was some body roll and maybe thats why the car felt safe . Yes maybe I could have gone a bit faster but my limit as a driver was maxed out alot faster than the FD's limit. The car could go faster , I could NOT

What I mean is that a harder spring setup may have produced a faster lap BUT and there is a big BUT the car may have been less predictable and more nervous close to the limit

So I would rather have a car that feels safe ( but still goes like hell ) rather than having a 100% race setup that may kill me or make me crash . And this comment is from a normal human being and not a race driver with loads of sponsor money that will repair his car for free hehehehe....

Rotors R Cool

A stiff spring alone doesn't make a car any faster. The stiffer springs allow you to change other aspects of the car such as ride height in order to lower the CG and gain performance. The downside always being that the stiffer springs are less forgiving and require the driver to truly know what the car will do rather than what it is doing.

You can only go so fast by reacting to the car. Once you can accurately predict the car, you will reach the next level of speed.

With soft springs you need only account for the general characteristics of the road to be quick. With stiff springs you need to account for the minute details of the surface and how they affect your limit of traction. If you are actually able to account for the details with soft springs, you will be limited by the physical limits of the equipment.

I agree. Softer springs are desirable for most of our uses. Most of the people on this board go to the track to race themselves. Racing yourself only requires that you do the best you can with what you have. Racing against opponents requires that your equipment be on par or better. This is when equipment must be top notch.

Rotors R Cool

Uncontrolled pair.

Metan

I wrote this information about 3 pages in front but...

i bought these Tein S-tech kit - Part number SKM32-AVB00 with slightly used 94´ stock dumpers
Mazda RX7 FD3S Tein S Tech Lowering Springs SKM32-AVB00 Only £193.39
lowering front 20mm, rear 25mm and spring rate - 7.8 / 5.8

then I set the aliggment,
camber
front neg 0.9 degrees
rear neg 1.3 degrees

toe
front toe in 1/15"
rear zero toe.

and what a car!

gracer7-rx7

iTrader: (16)

Another option is the Tein H-Tech springs.
F ~400 lb/in
R ~300 lb/in
Not much lowering with these though. If you use Koni shocks, I recommend setting the spring perch at the middle setting so that ride height is around 25 1/4 to 25 1/2 which is great for street and track use.

I used H&R springs for years and found them to be fine for both street and HPDE usage. I believe them to be equivalent to the Eibach springs but no one has tested their spring rates yet. Look in the suspension archives for past thread on those springs.


Those RSR "Down" springs are as difficult to find as Eibachs new. The Tein H and S Tech springs are readily available. I'd probably not recommend the Tein S-Tech's though. They drop the car very very low. Rishie at AutoRND has everything Tein and other brands.


FWIW, Another option is the RSR Race springs which are ~500 f and 400 r. I have a set in the garage gathering dust. Need to post them on the classifieds one of these days...

fd3s400438

@ METAN

then I set the aliggment,
camber
front neg 0.9 degrees
rear neg 1.3 degrees

I am suprised you decided to change completely the setup of the camber . From what I remember the OEM setup is -1 front and -0.5 rear

Normally the front camber is negative larger than the rear . ie my setup for the track was -2.2 front and -1.6 rear

I am surprised that you chose more negative for the rear since less negative at the front should give more understeer closer to the limit

Then again I might be wrong