Rear Suspension Mod To Suit Lpg Tank And Towing.

[Sixpack]

Hi all

I recently bought a FG 2010 XR6T sedan and will soon have it converted to LP gas liquid injection and am anticipating a problem with it having a sagging rear end with the weight of the gas tank.

Just recently we went on an interstate camping holiday and with all the camping gear in the boot and back seat the back of the car sank and stayed that way after returning when it returned to normal height.

Our previous BA also had an LPG conversion and I fitted rear towing springs which were 1 inch higher than standard. However with the gas tank full the back of the car was still raised higher than the front which didn't look all that good. The only time it was level was when towing or loaded with camping gear.

Would stiffer normal height rear springs/shocks be the answer? I'm not inclined towards airbags. Do they still make pump up shocks?

Has anyone had any experience with this?

Thanks

Sixpack

[spinr33]

From my past experience with car fitted with gas tanks aftermarket I normally go +25mm for the same height and normally go a king spring HD spring to combat it sagging more so and with towing I find it maintains the original height if it is stock height it should maintain that height with the +25mm HD spring and lpg tank fitted

[senna_T]

I would recommend Standard Height Kings coils, plus the poly bags for when you load it up more. They are the best way to keep the car comfortable with normal loads and then be able to hold the weight when you are towing and loaded up

[Sixpack]

Thanks for your replies.

I've got the XR booked in next week for the liquid injection conversion then I'll do the suspension next.

Cheers

Sixpack

[Spoony]

This thread sparked my interested (BFii XR6T on LPi (for 2.5 years now)). While the LPG system/tank it self made no difference (noticeable) to ride height I also drive loaded up and tow a bit, so often drag the bottom over things.

Have you done the springs/airbags yet? Curious to hear your throughts

I was thinking about just putting in the airbags and leaving the stock springs or do the king springs offer handling improvement too senna?

I certainly don't want to go any lower than stock, looking at the King Spring Cattledog though there is not stock hight XR6 BFii springs for the front available but :(

As of tomorrow the car will have Superpro bushes through the entire suspension, already has Bilstiens.

Edited 24/09/13 10:50 PM by Spoony

[Bellato]

If you're getting the bushes done I highly recommend having the springs and polybags put in the rear at the same time as the labour will be nothing as they have to pull them out anyway!

You can keep to standard springs but I think stock height kings are a slightly higher spring rate so a bit firmer but pat will confirm that.Shouldn't have to change fronts to match rears either if that's your concern

[Spoony]

cheers for the quick reply.

Just talked to Fulcrum (feels like I'm a share investor there lol) , they have a set of the bags in the warehouse so will fit the up also. He said that as you still have to run 6psi of pressure to keep them inflated/inshape so have a slight spring rate increase effect.

If I was going to go the springs I'd probably go all-round. Which I should have done on the weekend when the front was pulled apart. This whole suspension 'upgrading' is pricey enough and I keep adding to it haha, so will leave the stock springs for now. The front end feels much nicer with the super pro through it (and it already had SP lower front bushes done, the rest stock but in good nick), so no doubt the back which is flogged out will really transform it. That with the bilstiens should be good enough with the stock springs still I hope. I do a fair bit of distance/crappy road drivings so heavier springs would probably make it less comfortable for my back perhaps?

[Spoony]

EDIT: The Bilstiens have about 70,000kms on them, so will probably give them an overhaul in the next 40,000km (year or so) and do all the springs then. Costs are just getting to much at the moment with other $$ needs, bloody cars.

[Spoony]

Bit the credit card after reading 11ty threads on here about heavier springs and still maintaining a decent ride with bilstiens.

Along with all the new SP bushes getting king spring low KFFL-57P/ 520lb up front and low KFRL-68/HD 340lb HD rears. Low being standard xr height.

In Various threads using super low on the rear to level the sills (factory they aren't) , but currently mine is I assume due to the gas system.

Hopefully it's close go that with the above.

Canned also getting air bags as the spring rate increase is substantial. Loaded now I'm only flush with the rear guards so maybe drops 40mm or so.

With the new springs expecting maybe half that which is livable.

[Ralph Wiggum]

If they do drop too far SP also make spring seat's in varying thicknesses, you could use them to bring the car back to level when towing.