This is the roll center, suspension pickup, and steering angle modification thread.

[PoorMans180SX]

So I bought another chassis so I could have a car, and I put the TDP kit on it. It needs an alignment and power steering, but I can already tell it's going to be amazing. Please pardon the work-in-progress state of it, haha.

Wheels are 17x8.25+10 up front. I have a very small bit of ackerman dialed in.

[Matej]

Originally Posted by powahh

I need this too, trying to clear my headers

If it is the same as an S13 one, 11/16" x 36t.

[NotLowEnough]

Omg! Poormans180sx I have always loved your car but man thats awesome angle! Any shots like the 1st 1 just at full lock?

[PoorMans180SX]

Originally Posted by NotLowEnough

Omg! Poormans180sx I have always loved your car but man thats awesome angle! Any shots like the 1st 1 just at full lock?

Here's it on my old car:



TDP has just released previews of their rear kit! Robbie has been developing this kit for over a year. Pictures first, features after!









This kit has some unique features to give more grip and traction than anything else that bolts on. Its all fully adjustable in place. Its light and super strong. The one kit fits S13/R32 and S14,15/R33,34.

Key Features

-Three shock mount positions for ride height adjust-ability: STD, -20mm, 40mm
-Adjustable Roll Center.
-Adjustable Toe Height.
-Reduced camber gain under compression.
-Camber mount 75mm lower than standard.
-Traction mount 78mm lower than standard.
-Lower arm mount 55mm lower than standard ( Limited by wheel design )
-Innovative trailing arm system. Massive grip under acceleration.
-2 brake caliper positions.
-Upright / Knuckle only 4KG !!!!!!!!! (4 photos)

Customers with their front kit will receive a discount on the rear.

[simmode1]

^^^OMG that is so sexy... I bet they cost more than what I paid to buy my car...

[NotLowEnough]

Yessir!! That is just awesome! Seriously though, how much is this kit?

[PoorMans180SX]

Originally Posted by NotLowEnough

Yessir!! That is just awesome! Seriously though, how much is this kit?

The front was $2400 shipped a year ago, no idea now. Rear pricing is not announced yet.

[PoorMans180SX]

Originally Posted by PoorMans180SX

The front was $2400 shipped a year ago, no idea now. Rear pricing is not announced yet.

Rear pricing is 1999 Euros plus shipping. That's pre-order, normal is going to be 2400 Euros. So figure $3k shipped here if you get in on the pre-order.

[Jifter]

Hey Poormans180, are you running a relocated rack plus offset tierod spacers? If not, has anyone done a setup like that before?

[az_240]

^You can only go so far before the tie rods/rack interfere with the cross member. It's really best to just relocate the rack 20-25mm and be done with it.

[PoorMans180SX]

Yeah I just have offset spacers.

[Jifter]

ok. cool thanks guys

[Jifter]

I also wanted to ask, what rubber boots do you guys run on your racks with offset tierod spacers? I have nothing on mine right now cuz stock ones are obviously way too short

[tobroketobuildarealcar]

I am running stock ones with no problems

[PoorMans180SX]

I run B15 sentra ones.

[Jifter]

Originally Posted by PoorMans180SX

I run B15 sentra ones.

Sweet. Thanks!

[derass]

Originally Posted by Jifter

I also wanted to ask, what rubber boots do you guys run on your racks with offset tierod spacers? I have nothing on mine right now cuz stock ones are obviously way too short

Originally Posted by tobroketobuildarealcar

I am running stock ones with no problems

I also have stock S13 boots over offset rack spacers.

[jackal264]

what's considered safe as far as how much thread is used on inner and outer tie rods with extended lca's?

right now i have tein inners with spl outers and i can only get about 5 full rotations of the adjustment sleeve on the inner and outer sections. it equates to about 1 cm of threads.

is that safe?

lca's are extended 40mm

[n2o_matt]

rule of thumb is typically 1 diameter of thread engagement for steel...

but if you want to be sure/use some maths, google told me:
http://www.engineersedge.com/thread_...engagement.htm

[derass]

1 x Diameter for steel, 1.5 x Diameter for aluminum. I drifted all last year, 13 events with only 1 x Diameter engagement. I'm not even sure what the buckle material of my DMAX outer is. Sketchy, but i didn't have a problem. However, I was only using UHP tires up front, something stickier and I could have potentially ripped the threads out.

[turtl631]

This is quite the thread. I'm interested in track days, "grip driving" as the kids say, and sizing up the upright options. I'd like some reasonable roll center and bump steer correction, and faster steering would be nice as our stock racks are pretty lazy. Unfortunately missed the boat on the GKTech uprights. So, is anyone selling an S14 set? Alternatively, anything else out there that would be reasonable for my application? Most of what I'm seeing is focused on mega angle, zero ackerman.

[heychris]

@ turtl631....Not knocking Zilvia. I am a long time member here, but check out the forum at nissanroadracing.com. ..they are very "grip" oriented...lots of the info you are looking for will be there..

Good luck
Ch

Sent from my SM-N900V using Tapatalk

[turtl631]

I've been a member there since the start. Just thought I would ask here since lots of guys are active on both and this has a more active discussion about uprights.

[az_240]

PBM front knuckles are great for the money. Everyone I know who has them loves them (myself included). They'll make the steering arm same as stock if you want but I think the lower ackerman/quick steer style would still be very good for grip.

[n2o_matt]

Originally Posted by turtl631

This is quite the thread. I'm interested in track days, "grip driving" as the kids say, and sizing up the upright options. I'd like some reasonable roll center and bump steer correction, and faster steering would be nice as our stock racks are pretty lazy. Unfortunately missed the boat on the GKTech uprights. So, is anyone selling an S14 set? Alternatively, anything else out there that would be reasonable for my application? Most of what I'm seeing is focused on mega angle, zero ackerman.

I see the GKTech's are "out of stock", are they gone for good?

[Jifter]

Hey guys,
I have welded my knuckles on my s13 for zero Ackerman. Im running notched LCAs which have been extended 20mm. VooDoo13 curved tension rods. I also have offset rack spacers installed. Zero toe. This setup is producing some wicked lock. In dry conditions its just amazing how hard I can throw the car into the corners with mental angle and keep my speed.

I wet conditions, my car became the slowest one of all.. Im just wondering if any of you zero ackerman guys have experienced this?

My theory behind this is;
Ackerman will always be present with a sliding rack setup. Its impossible to achieve linear Ackerman with a sliding rack setup. On my setup (and most setups), with the wheels pointed straight and zero toe, the tie rods are swept back (angled back from the rack spacers to the knuckles). At full lock, the tie-rods are swept forward. At mid lock, the tie-rods are perfectly inline (straight across) with the steering rack. This means the overall length (between rod end pivot points) is a bit longer at mid lock compared to full lock or having the wheels pointed straight. Since the overal length is longer at mid lock, this will cause toe-in at mid lock. Toe-in will cause a crab walking effect (lots of car angle) but a loss of forward bite during a drift. I believe this loss of forward bite is allot more noticable in wet conditions since its hard to achieve forward bit in the wet to begin with.

Is running a few degrees of toe-out the solution to this problem? Doing so would keep the wheels parallel at mid lock (keeping you from crab walking). The downside to doing this would be a few degrees of toe out at full lock. It wouldnt be a bad thing running a bit of toe-out at neutral though since it would help with turn in.

Im interested to hear from you guys running "zero Ackerman" setups. How much toe are you running? How do you guys like it in wet conditions?

Thanks,
Jake

[PoorMans180SX]

Originally Posted by Jifter

Hey guys,
I have welded my knuckles on my s13 for zero Ackerman. Im running notched LCAs which have been extended 20mm. VooDoo13 curved tension rods. I also have offset rack spacers installed. Zero toe. This setup is producing some wicked lock. In dry conditions its just amazing how hard I can throw the car into the corners with mental angle and keep my speed.

I wet conditions, my car became the slowest one of all.. Im just wondering if any of you zero ackerman guys have experienced this?

My theory behind this is;
Ackerman will always be present with a sliding rack setup. Its impossible to achieve linear Ackerman with a sliding rack setup. On my setup (and most setups), with the wheels pointed straight and zero toe, the tie rods are swept back (angled back from the rack spacers to the knuckles). At full lock, the tie-rods are swept forward. At mid lock, the tie-rods are perfectly inline (straight across) with the steering rack. This means the overall length (between rod end pivot points) is a bit longer at mid lock compared to full lock or having the wheels pointed straight. Since the overal length is longer at mid lock, this will cause toe-in at mid lock. Toe-in will cause a crab walking effect (lots of car angle) but a loss of forward bite during a drift. I believe this loss of forward bite is allot more noticable in wet conditions since its hard to achieve forward bit in the wet to begin with.

Is running a few degrees of toe-out the solution to this problem? Doing so would keep the wheels parallel at mid lock (keeping you from crab walking). The downside to doing this would be a few degrees of toe out at full lock. It wouldnt be a bad thing running a bit of toe-out at neutral though since it would help with turn in.

Im interested to hear from you guys running "zero Ackerman" setups. How much toe are you running? How do you guys like it in wet conditions?

Thanks,
Jake

I have been tossing this theory around as well. On my knuckles ackerman is adjustable, so I can mess with it and kinda see how it feels in each setting. I also have rack offset spacers. I had my ackerman quite positive and liked it, then I pushed it a good bit negative and experienced exactly what you're saying. In the dry it was fine, maybe a bit of understeer, but it slid really well. As soon as it rained it was a dog, understeering and feeling really strange in the middle of lock. I have the ackerman very slightly positive now and I love it! So much more grip, it literally never understeers.

The rack location definitely affects the "ackerman curve" throughout the steering range, so I think what you're describing is accurate. I would say the ultimate solution is moving your tie rod pick ups in slightly on the knuckle, so you never get that mid-lock toe-in. But a bit of toe-out is probably a decent interim solution.

[Jifter]

Im glad to hear you've experienced the same weird feeling I mentioned at mid lock. Like you've done, running a bit of + ackerman would definitely keep the wheels from toeing-in at mid lock. Doing so would cause undesired toe out at full lock though.
I believe the ultimate setup would be to have knuckles set at zero ackerman and running the exact amount of toe out necessary to keep the wheels perfectly parallel at mid lock. The amount of toe out added, will add the same amount of extra steering angle at full lock on the leading wheel.
Also, I believe the shorter the knuckle arm, the more linear the ackerman curve will be. The downside of running a super short arm is steering sensitivity. My arms are 3 1/4" eye to eye and my steering is much more sensitive compared to stock knuckles. I wouldnt recommend anyone going much shorter then 3 1/4".
I plan on taking my car to a shop to get lifted so I could have a better view of how much my wheels are toeing in at midlock. I will try to toe out accordingly.

Here is a shot my s13.32 at close to full lock

[O$mo]

I have a question.

I have a s14, and I am about to run 25mm extended LCA, Moog outers and Ikeya formula inners, with the spacers. I also have PBM tension rods.


Do I have to run modified knuckles or no.

Thanks in advance.

[Motary]

Sure if you want higher roll center, more steering angle and improved bumpsteer, but you don't have to have them