Jump to content
SAU Community

Suspension Setup For Towing


Recommended Posts

My stag sits way too low when towing my evo- need some advice for type of suspension for height adjustments

- Do coilovers allow you to raise the height above standard or would it be better to get super stiff springs to avoid a sagging ass? I dont want to lower the rear any more than it currently is so "stiff lowered springs" would not be suitable

oh and as you can see the front looks like a boat with all that weight in the back, so coilovers might be a good idea so i can balance the car out on long road trips

Any tips appriciated

IMG_0058.jpg

Edited by EvoMitchy
Link to comment
Share on other sites

Looks like your main problem is your towball weight, not suspension, check that it doesnt exceed the towbars ball weight specs, i think mine is around 150kg. Looking at yours id guess it would well over that. Ive loaded the boot with 200kg of cement and it never looked that bad. I tow my boat with a TBW of around 50kg, but to achieve this i had to reposition the trailers axles forward, unfortunately not an option for you. Are you able to face the EVO backwards, would this get more weight to the back of the trailer ? and that spare tyre on the hitch doesnt help, can it be repositioned under the back of the trailer?

Changing your suspension would be fine if you towed this 100% of the time, you are better off addressing the cause.

Link to comment
Share on other sites

Looks like your main problem is your towball weight, not suspension, check that it doesnt exceed the towbars ball weight specs, i think mine is around 150kg. Looking at yours id guess it would well over that. I tow my boat with a TBW of around 50kg, but to achieve this i had to reposition the trailers axles forward, unfortunately not an option for you. Are you able to face the EVO backwards, would this get more weight to the back of the trailer ? and that spare tyre on the hitch doesnt help, can it be repositioned under the back of the trailer?

i'm certain there is no more than 150kgs on towball- its the couple hundred kilo's of gear in the back that help it sit on its ass lol. Wheels, tools, etc- all adds up and i'd rather it be in the car than to put the extra weight in the trailer

although out of curiosity, how would i be able to test the weight on towball??? I experimented with some car positioning and unfortunately if the weight is too far back it is very twitchy when driving at speed (or as my mate calls it- "a tank slapper" lol)

Link to comment
Share on other sites

Looks like your main problem is your towball weight, not suspension, check that it doesnt exceed the towbars ball weight specs, i think mine is around 150kg. Looking at yours id guess it would well over that. I tow my boat with a TBW of around 50kg, but to achieve this i had to reposition the trailers axles forward, unfortunately not an option for you. Are you able to face the EVO backwards, would this get more weight to the back of the trailer ? and that spare tyre on the hitch doesnt help, can it be repositioned under the back of the trailer?

that was my thoughts, too much load is on your towball by the looks. the only problem i see with putting the car on the trailer backwards is possibly putting too much weight BEHIND the axles in turn making the trailer very uncomfortable to tow. i've seen 2 accidents caused by this - one had the car on the trailer backwards and the other had the car too far to the rear of the trailer.

ideally weight should be forward of the axles but definitely looks like you've got alot of weight being transferred to the tow car.

Link to comment
Share on other sites

should also add this could be due to the relationship between your tow ball and the trailer hitch bit ie one higher/lower than the other

i'm hoping this is the answer mike, because its an easy fix- first stagea with a lift kit haha

so... how do i find out how much weight is being transfered to the tow ball? i'm still sure that most of the sag is caused by my gear in the back, but best to be safe. That said i drove over 2500kms with the evo strapped to the back with no drama's

Link to comment
Share on other sites

i'm certain there is no more than 150kgs on towball- its the couple hundred kilo's of gear in the back that help it sit on its ass lol. Wheels, tools, etc- all adds up and i'd rather it be in the car than to put the extra weight in the trailer

missed this post, if you're certain it's not the load on the tow bar then the only option is stiffer spring rates. just make sure that if you upgrade your springs (whether it be aftermarket non adjustable struts or coilovers) that you also take into consideration upgrading your damper rates to match them

Link to comment
Share on other sites

measure your towball weight with a set of bathroom scales, if you have a set that goes that high, use a piece of wood to protect the scales, and place the scales on some blocks so the height is same as your ball.

Link to comment
Share on other sites

ahh you got Bryce's old rig looks good. Last i was talking to him before he sold it he mentioned that the suspension was getting a little soft. So old shocks/springs with that load will definitely sag. my suspension is shot in my stag one of my struts doesn't even have oil in it anymore and yes like you i plan on towing my race s13 around i have chosen to go the tein gt wagon coil overs they are height adjustable (can go higher than stock) damper adjustable and spring rate adjustable perfect to get the exact right ride for towing it's like they where made for it. when looking for coilovers take special notice of if the bottom if it moves up/down good. Compared to adjusting ride hight with the spring rate not good for towing to stiff might break something.

Link to comment
Share on other sites

my suspension is shot in my stag one of my struts doesn't even have oil in it anymore and yes like you i plan on towing my race s13 around i have chosen to go the tein gt wagon coil overs they are height adjustable (can go higher than stock) damper adjustable and spring rate adjustable perfect to get the exact right ride for towing it's like they where made for it.

Thanks for the info Matthew- the teins sound like they are pretty much what i'm after. Do you have a rough idea on price, and where will you be sourcing them?

Link to comment
Share on other sites

why do you want it to go higher than stock ? do you want it to look like a dragster when your not towing anything? or by higher are you refering to the threaded collars on the shock body that you can wind up higher to increase preload on the spring?

Link to comment
Share on other sites

My stag sits way too low when towing my evo- need some advice for type of suspension for height adjustments

-quote]

I agree with those who say you should address the weight on your towball but there are a number of airbag solutions that allow you to retain your current suspension (assuming that you are happy with it while not towing). I believe these involve inflating the airbags for towing and releasing the presure afterwards. Here is one such (I am sure there are others in Aus - ring a major caravan club and someone will be able to advise you): http://www.stengelbros.com/AirLiftAirAux.Springs.htm

Link to comment
Share on other sites

  • 1 month later...

Just wanted to add that I tow my gtr behind my stag all the time (same as you full of gear in the boot too) and there are 2 key things.

Keep the towball weight at a decent level. In your case just let the car sit back further (lengthen the front tie downs.)

Stiffer shocks and springs, I ran gary's bilstein/eibach setup at the rear about 2cm higher than standard. Not sure of the spring rates but definately harder than factory. No pics handy I will try and take some next time its loaded up.

edit actually heres a crap pic when it had the commodore on the back. about 300kg more than the gtr it still sits higher at th front but pretty good considering how much load there is

stagea_towing.jpg

Link to comment
Share on other sites

Yeah sounds like your shocks and springs are shot, and looking at the pics I wouldn't be surprised if the rear of your stag is almost sitting on the bumpstops.

Although I am certainly no expert on the subject I would have thought a good set of coilovers with some reasonable weight springs in the rear would be the way to go. Get coilovers with lower adjustable spring seats in the rear this way you can adjust the preload in the rear to compensate for the added weight.

I believe the std stagea spring rates are around 3-3.5kg

FYI I run 8kg front and 6.8 kg rear eibach springs in my Stagea and it is still pretty comfortable for every day use. Also when you get rear springs ensure you get ones with linear coils as progressively wound coils will sag straight away as soon as you put the trailer on.

Link to comment
Share on other sites

Doesn't sydneykid use his for towing a car trailer? Definitely worth putting the question to him...
Just wanted to add that I tow my gtr behind my stag all the time (same as you full of gear in the boot too) and there are 2 key things.

Keep the towball weight at a decent level. In your case just let the car sit back further (lengthen the front tie downs.)

Stiffer shocks and springs, I ran gary's bilstein/eibach setup at the rear about 2cm higher than standard. Not sure of the spring rates but definately harder than factory. No pics handy I will try and take some next time its loaded up.

edit actually heres a crap pic when it had the commodore on the back. about 300kg more than the gtr it still sits higher at th front but pretty good considering how much load there is

stagea_towing.jpg

Did a search a while ago, 5kg front, 4kg rear, he said he would be trying ~5kg rear soon as it was a little on the soft side for towing, so maybe 6front, 5.5 rear?

Yeah sounds like your shocks and springs are shot, and looking at the pics I wouldn't be surprised if the rear of your stag is almost sitting on the bumpstops.

Although I am certainly no expert on the subject I would have thought a good set of coilovers with some reasonable weight springs in the rear would be the way to go. Get coilovers with lower adjustable spring seats in the rear this way you can adjust the preload in the rear to compensate for the added weight.

I believe the std stagea spring rates are around 3-3.5kg

FYI I run 8kg front and 6.8 kg rear eibach springs in my Stagea and it is still pretty comfortable for every day use. Also when you get rear springs ensure you get ones with linear coils as progressively wound coils will sag straight away as soon as you put the trailer on.

Standard: 2.9/3.1 165/175

If you are in melbourne, when i come closer to redoing my rates and valving i wouldn't mind a test ride if possible!

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share



  • Similar Content

  • Latest Posts

    • With same diff ratio, tyre diameter and road speed, the tailshaft rpm is the same regardless of the gearbag's ratio. Given that very quick drag cars are probably doing similar road speeds to the fastest circuit cars (circa 300 km/h), and there will be many of either category that can't go that fast and so you'd have inummerable matchups between drag and circuit car speeds at smaller numbers, and given that they are probably using rather similar tyre diameters and probably using similar diff ratios, and...where any of those numbers were different they could quite easily be in opposite directions thus cancelling out.... I think you'd find that there'd be more similarity than difference in tailshaft speed between these two use cases, no?
    • they might see those prop shaft speeds for 1 to 2 secs only 
    • A year of slogging through this bearing issue and finally fixed. What a nightmare. The oil pressure increase did not fix the problem. If you would like to read all the details in case you ever run into a similar issue visit my thread on Yellow Bullet. https://www.yellowbullet.com/threads/continuous-rod-bearing-issues.2689569/?post_id=74193031&nested_view=1&sortby=oldest#post-74193031 In the end the rod bearings themselves were the issue. I had switched from ACL (first engine) to King because that was all we could get at the time and I thought nothing of it. Put the ACL's back in after a year of taking the pan off multiple times to change many things. Issue resolved. Can't believe it was just the bearings themselves all along. It has now been about two years since I drove the car on the street or had it at the track. At some point I had installed all solid and spherical bushings in the rear but had never aligned it since it just went on and off the dyno. Alignment was the first thing to do. (Old photo but same concept) Then I took the transmission out and went through it. This was my first gearset install and I've done about 15 since this one and learned a lot and wanted to apply some of these tweaks to mine. The aftermarket shift forks take very well to some modification and I wanted to make that change. Shifts are now super smooth and no having to find the gear. I also recut the 5th and reverse shift sleeves - always wanted to try this and see how well it works. It works very well! No grinds or having to do a second attempt going into reverse and 5th is perfect. Before During After Going back in In rummaging through my spare trans parts box I found the only parts I've ever broke on a stock trans; the 3-4 shift fork - twice!  
    • It also depends on gearbox ratio. Those drag cars running 7s passes aren't doing it on an overdrive gear ratio (probably). 1:1 is "fine", the critical RPM for a 50' single driveshaft in chromemoly is 6900rpm.... ....but when you shift into 5th and use 0:73 or 0:8 it all changes. Do you know their rear diff ratio? etc. That's the stuff that matters with regards to it. Whether it actually matters given your use application is also relevent. You may never get into those scenarios, like most ruined GTR's from Western Sydney don't :p
    • but for how long? would it handle a few laps around SMSP in anger? 
×
×
  • Create New...