s15 suspension questions

[deadghost]

Tell me what you guys know about the S-15 SUSPENSION, do not get me wrong I know the basics of the car but I what to know it in a crack shell, I get a little tired of going over wikipedia for the 5th time and finding very light information, let me hear it from the fans, tell me the important facts (suspension), tell me what I should & need to know.

[veilside180sx]

It's the same basic components as an S14. Search for that and you'll get your answers

[BoostedCoupe]

If you wanting feedback from others that have a s15 this is the wrong forum. Not many of us have a s15 on here. Maybe 1 or 2. your best bet would be to go to an austrlian forum or japaness forum and ask there.

[S13ORLANDO]

If you wanting feedback from others that have a s15 this is the wrong forum. Not many of us have a s15 on here. Maybe 1 or 2. your best bet would be to go to an austrlian forum or japaness forum and ask there.


Hey,
Try these guys for some input.
http://www.driftworks.com/

http://www.driftworks.com/forum/drift-car-projects-builds/46751-nissan-s15-silvia-next-level.html
good luck,
Bob

[!Zar!]

s15 susp is pretty much the same as s14.

Nothing big.

[Dousan_PG]

yah basically same
same setups and shit
u can use s14 arms on s15
LCAs are the same too
biggest difference will be the subframe

thats about it.

[Jonnie Fraz]

On the subframe, I had heard that it is configured more for anti-squat...true or false?

[Dousan_PG]

true

mssg length

[FRpilot]

are you planning to put s15 subframe on your s13?

[Dousan_PG]

yeh eventually. when i find out...oh reminds me to call smoeone about it...

[!Zar!]

Couldn't someone just put a spacer between the subframe and the frame to adjust for antisquat/prosquat.

[Dousan_PG]

relocate your LCA mounting pionts would work

[!Zar!]

That's another possibility.

Just figured it would be easier to try and adjust with spacers/shims as opposed to redrilling the lca location.

[Jonnie Fraz]

relocate your LCA mounting pionts would work

Any dimentions on that relocation? :bow:

[!Zar!]

Looks like Kuah already one upped me and already has the subframe spacers. Price is about $60~

Hard urethane subframe bushing spacers are used to tune anti-squat by rotating the instant center of the rear suspension through rotating the subframe or moving the subframe relative to the center of gravity:

*

For maximum squat (eg. drag racing), rotate the instant center down by installing large diameter spacers above front subframe bushings and small diameter spacers below rear subframe bushings.
*

For slightly increased squat, lower the instant center by installing spacers above all subframe bushings.
*

For slightly increased anti-squat, raise the instant center by installing spacers below all subframe bushings.
*

For maximum anti-squat (eg. drift), rotate the instant center up by installing small diameter spacers below front subframe bushing and large diameter spacers above rear subframe bushings.

Note: These spacers cannot be used in conjunction with subframe collars.
http://splparts.com/main4/parts/NissanShared/Suspension/Subframe/SPLSubframeSpacers.jpg

[Dousan_PG]

i like those ones
ill get them later (august)
no car parts in May
MUST
CONTROL!!!

[FRpilot]

yea those pineapple spacers have been out forever

[!Zar!]

i like those ones
ill get them later (august)
no car parts in May
MUST
CONTROL!!!

Because you're secretly building a Fixie?

[Dousan_PG]

hahah yeah right
no vacation coming up
must save

spend money for ASB!!!!

[90KAcoupe]

im affraid there is alot of mis information in this thread.. i have done some research on the s15 subframe swap.. The s15 subframe is a direct bolt up to a s14 and the s15 rear suspension has way better toe curves then the s14 did.. the s15 subframe does not add anti-squat. the s13 subframe has the bad anti-squat problems.

so basically in order from best design to worst design is

s15>s14>s13.

[!Zar!]

S15/14 subframe adapters for s13. (http://www.tougefactory.com/shop/index.php?itemid=1026&cat=308&shop=1&)

[Full-Lock]

i ran front s15 coilovers on my old s14

that is all i know!

[90KAcoupe]

another question?? why the hell do u want to add anti squat.. u want to take all the resistance possible out of the suspension so the shocks and springs do all the work...

[!Zar!]

Wow. Who was talking about misinformation now?

Have you measured the amount of anti squat the s13/14/15 has? Do you know how much more would effectively bind the suspension?

I'm thinking not.

People have been doing this for ages.

[FRpilot]

S15/14 subframe adapters for s13. (http://www.tougefactory.com/shop/index.php?itemid=1026&cat=308&shop=1&)

wow. i thought the s15 subframe was too wide to fit in s13s and although you can fit it by forcing it in, solid bushing were not an option. are the holes for those bushings not centered to accomodate it to fit an s15 subframe into s13?

now i can find an s15 subframe, use the greddy s14 diff cover, and mix those bushings with spl's other solid bushings.

mel, where do you hear about all these products so quickly? like the cs oil cooler kit? do you constantly refresh phase2 and tougefactory's sites?

[90KAcoupe]

im just going off the definition of anti-squat.. and why would u not want ur car to squat if needed. to get traction coming out of a turn u would want the back in to squat instead of sliding out.. and if this isnt the case then why do most s13 road racers want to swap the s15 subframe into their car.. im just going off of people that have alot of intelligence with suspension building..

[!Zar!]

There is no definitive setup.

Things like anti squat/anti dive and pro drive are more driver preferences than set in stone setups.

It's all part of alignment. Each driver likes different things.

It just changes how the car enters/exits the corner.

[90KAcoupe]

i've never thought of that as being driver preferance.. there is always something better then a different setup.. alot of times the driver need to compensate for the change in order to be faster. to me it seems like if the car will squat exiting a corner giving more grip would ultimately make it faster.. and if it doesnt tend to want to squat and causes a little more oversteer. yea the driver may be able to drive it better but he is ultimately slower then if he learned to drive with more grip.

and im not trying to fight.. im trying to enlighen my self. so please dont take this as an attack..

[!Zar!]

Not really, it's a tuning aid and you adjust it per track, need.

Effects of anti dive.

1. On corner entry the rear suspension will resist lifting.

2. If you use a stiffer front spring and have little rear droop may result in less off-power steering.

3. The maximum roll point of the rear suspension is reached faster.

4. Off-power steering mid-corner will be reduced until power is applied.

5. On corner exist the rear suspension resists squatting.

6. With reduced rear weight transfer on-power steering increases as throttle is applied.

7. Reduces rear grip on corner exit.

8. The rear suspension has a better ability to handle large or successive bumps.

[90KAcoupe]

alright.. i get some of ur points.. but wouldnt u want to adjust these things with the compression and rebound of ur shocks and the spring rate of ur springs.

for #1 if ur rear end was trying to lift, wouldnt u stiffen front compression and/or loosen the rear rebound, so ur rear wheels will stay on contact with the track surface

for #3 would u not want the ability to reach the maximum roll point.. you would just adjust your shocks to limit the speed in which u get there??

for #4 im confused on how if the suspension in the rear is resisting is resisting dive or ltting it dive would effect off power steering.. the suspension will be acting the same either way..

for #5 yea and why would u not want the suspension to squat.. if it squat u will be able to get more power to the wheels.

For #6 it seems like if the rear didnt squat it would be more tent to over steer when more throttle is applied.

For #7 why do u wanna reduce rear grip??

For #8 it seems like if the suspension didnt like to move freely it would cause the bumps to me alot harsher causing disturbance in grip..

maybe im completely off on my theory.. im just trying to figure stuff out. and if i hear something i dont completely agree with.. im not going to believe it untill i see decent evidence...

[spool_sample]

maybe im completely off on my theory.. im just trying to figure stuff out. and if i hear something i dont completely agree with.. im not going to believe it untill i see decent evidence...

There's not really any need to question it, it just works. The points that Zar posted are the same that I've seen and experienced myself. In simple terms, more anti-squat will make the car more prone/easier to throttle steer... less anti-squat will do the opposite. It works really well for drifting and getting cars with relatively little rear roll stiffness to rotate on power.

It's just another suspension tuning tool, basically.

[90KAcoupe]

i think i may understand how it works.. now.. im gonna do some more studying instead of talking on here.. and i'll post what i come up with