TRD shocks and springs

[NoHachi]

Well, the answer is....drum roll. I don't know

Unless somebody manages to dig up some dyno graphs there is really no way to know. Al that remains are educated guesses.

We've seen the marketing graphs for the HTS and according to rumour they are ok. The HTS is linear in the lower settings and digressive with higher settings, best enjoyed with stiffer springs but reasonable at lower rates.

If you want to find a reasonable set of koni's, then best thing is to look which car matches the AE86 best in springrate, cornerweight and suspension type. If someone can dig up the stock AE92 springrates? SW20 is 3.75kg/mm, but has a 60kg (25%) higher cornerweight. I'm guessing that they will be too stiff for 3kg/mm springs on the AE86.
You definitely want to find a set of koni's where you do not need to touch the adjuster. If the AE92 ones are really monotubes (how can you tell?) then they might be a very good option indeed.
Maybe someone can bug the guys over at McNamera for the TRD shock printouts. They advertise everywhere that they had Spax copy the TRD curves exactly, so they shouldn't have any problems with coming up with those figures.

Bilstein is my personal favourite, but you would have to get some cheapie secondhand units and have them refurbed and revalved. To much of an hassle for most people, but cost effective if you know the right people. Lots of inserts will fit, but S13 inserts, shaved 1mm to fit inside the cartridge are best and have the beefy 36mm internals.

I really need to build that shock dyno that I have been dreaming about. If someone can get a hold of a load cell (0-300kg) or linear position transducer and wants to sponsor the forums, send an email.

[jondee86]

All interesting and good comments... thank you

As in most things, there is no perfect answer. Soft and compliant
suspension does not happen with short stroke shocks and low ride height.
To avoid being on the bumpstops all the time, the spring rate must go up
as the car goes down. I already knew that, but now I understand the
reasons a little better

The idea of BC (or equivalent) coilovers was attractive because of the
degree of adjustability in height and balance. My reservation was always
about the spring rates rather than shock valving. However, I can see that
the two (spring rate and valving) are intimately connected. Changing to
softer springs demands greater travel, which is not really available from
the coilover design. It also means the valving will be too harsh, and will
no longer match the spring rate.

I hope I have understood these things correctly

For now I shall stay with the spring rates and struts that I have. What I
shall try to find is some Koni (or Bilstein) shocks that have suitable rates/
valving to match my setup. As said elsewhere, I see no need for having
adjustment more than off-car adjustment as with Koni yellows. If the
shocks are matched to the springs, they should work under all kinds of
driving conditions.

Re-valving is possible either here in NZ or in Australia. So if I have to
get some SW20/AE92/Camaro shocks re-valved, it can be done. All I
need is to find a technician (shock engineer) who can advise me on the
best valving for my use... that will be the hard part !!

Thanks and regards... jondee86

[NoHachi]

Quote:I hope I have understood these things correctly

100%

Quote:Re-valving is possible either here in NZ or in Australia. So if I have to
get some SW20/AE92/Camaro shocks re-valved, it can be done. All I
need is to find a technician (shock engineer) who can advise me on the
best valving for my use... that will be the hard part !!

If you can organise someone to measure the center of gravity height (or a close estimate with scales) and front roll center height (measure your front LCA angle and strut angle with e.g. an iPhone and measure strut top-to ball joint length).
If you give me those inputs I can give you a valving recommendation that will be in the ballpark for your needs.. say 85% of whats possible. The final 15% is trial and error, thats why expensive shocks have those knobs. No worries, a pair of billies at 85% blow everything available for the 86 out of the water.

[jondee86]

Yeah... I have been in touch with the Bilstein distributors. They have
built shocks for the AE86 before, and think that with my spring rates they
can probably use the standard AE86 listings with modifications.

Back shocks with an internal spacer to limit the extension and keep the
springs captive. Front inserts with both body and rod cut down. Since the
standard listings will be valved for uprated "lowering springs", it sounds
as if this will be a viable option.

They also say they should have shock dynos and other data from the
previous AE86 sets they have built, and that they can make these
available if I get serious about the purchase. I am going to send them
details of my setup and get a firm price for a full set of shocks. Should
be interesting. Estimated price ca Euro600 for the set

Cheers... jondee86

[NoHachi]

600 for new bilsteins, cut, modified and revalved is cheap. Lots of labour involved.
If you want to get serious, try and fit some 36mm options. There are a couple of insterts that don't fit by a mm or so. So use a honer on the housing and shave down the shocks themselves.
The 36mm have a bigger piston and a lot more revalving options. Its a lot easier to get a more digressive valving with them. They will also last longer and work better.
If they are doing the revalve anyway, try and have them leave the bilstein shrader valve in (modify the strut to suit). You can then add an external canister from a motorcycle and get low and high speed bump adjustment. Bilstein also do a rebound adjustable pistonshaft, but its mucho dollars.

[SekiguchiUeno]

Jondee: well i dont know either about the top adjustable konis, we can get them in europe for almost the same money at the agx and i newer riden some car equipped with them(agx). They said they are gas shock in some older catalogue that means to me monotube. I think they are equal to agx.
Nothing can beat bilsteins(thats the old rule comparing to konis they are some class better, i was amazed as i first mount them on the car, how comfortable they are, not sure was is meant by disgresive but thats probably the same as degresive curve, they act very stable in corners at slow rod speeds but absorb bumps prety good. even the stock version with smaller piston in the front. The front is upside down and the lower casing has some bushing pressed in while the piston rod is mounted on the bottom of the downtube. Even the stock B6 can probably work good with 3kg spring. Problem can be your 40mm lovering and cuted strut housing. I fix noncaptive springs with olds man engineering methods like belts on the rear axle and wires on the front struts. But i dream to let me build some matched and shortened set in the future from them.

600 for revalved shortened and matched set is pretty good, stok ones costs around 500euro here in eu. Revalving shortening adds about 45-50euros to one damper done directly by bilstein. It is basically rebuild so its better to sent them some used old ones.

Nohachi> as i wrote in other topic i have the idea of 200sx fronts linger in my head with complete swap, i am not sure what exactly want you grind down by 1mm on the shock? The outher shell is basicaly some thin tube with some bushing pressed in and in the 200sx version there is the spindle connection welded on. 36mm is the diameter of the upper part of the front shock? As i will be in the garage i can measure the upper part of the ae86 B6. Have you some other measurements of the nissan front shock? As the shell body, rod travel, stock springrates etc..?

About the external canister i have some integrated on my rear bike shock it is compressed via schrader valve with special air pump, it would be nice touch to have on car shocks, so you could change oil from time to time on them.

[jondee86]

I have had Koni yellows before in standard length struts, and once they
were installed, I never found any reason to adjust them After all, who
wants to have to dismantle the front suspension and take the insert out
to adjust shocks !! My understanding was that the adjustment was only
there to compensate for wear.

I'm not a hardcore racer. I don't want rock hard suspension. I don't
want/need knobs, valves, external reservoirs, height adjustment or
complications... although height adjustment would be nice. Maybe I'll
convert my struts to coilover one day. I want "set and forget"

What I am looking for just now is a set of shocks customised to suit my
car. I already have the AGX which fit, but which were designed for
other cars with different weight and springs. They work, but there is
definitely room for improvement. As you say, B6 or B8 cut down to suit
my struts should be suitable. I'll see what the Bilstein agent suggests.

Cheers... jondee86

PS: I came across this site again...
http://farnorthracing.com/autocross_secrets6.html
... and it makes a lot more sense now

[totta Crolla]

Just done a comparison between Bilstein B6 and TRD blue 4 way. Both sets front and standard length using 9'' 300lb coils.
Personally I prefer the TRD's just as good over the bumps (setting 3) but considerably better when turning in (grip) and correcting oversteer.
300lb might be too much for the B6's as I remember they were very good with 190lb springs.
Still not as good as the TRD's with 300's though !

[NoHachi]

300lbs is a bit much for a shock designed to work with springs that are one third as stiff. No big surprise there. Oversteer corrections are easier with stiffer cars since you don't have a delay from shocks and springs.
Good to hear that TRD combines ok with 5kg springs, would be lovely to see some dyno graphs for them.

[jondee86]

Here are the suggested Bilstein shocks for my 3.0/2.8 kg/mm springs...


And...


How do these look for a mainly road, sometimes track car ??

Cheers... jondee86