Towing with a Sirion

Hey all.

So we plan on towing a caravan with the 1.5 sirion. It’s a small caravan so weight shouldn’t be a problem. At least for the brakes and engine. The springs on the other hand…

Anyone can tell you that as soon as you put any weight on the rear axle of a Daihatsu that the springs will bottom out almost immediately. Does anyone have any experience with towing anything behind a siron and what was your solution to the rear springs?

We found these but I’m afraid that the ride height will be way to high without any load.

Any suggestions? Please drop them here!

Don’t go by the visual length. That black section where the coils are close together “should” collapse and bind under the unladen car weight. That section is there to keep the spring in place or captive when one side extends all the way out/down. The uprated spring should make it handle a heap better without the caravan too.

The website you shared doesn’t provide a lot of info and I’m not sure what the 10-50% means"? 10% increase would be pointless, 50% moderate and you’d prob be best with double the rate or 100% more

Okay thnx, this website was the first one we found. 10-50% is the increased sprig stiffness which seems like it wouldn’t be enough. They say that it will become stronger the more you compresse it . But if it only provides 50% more stiffness I doubt that that will be enough. The problem with my own 100% stronger springs is that they “bounce” once fully extended due to no preload etc so that isn’t an option I would suggest.

Good to know that the black part is supposed to fully collapse as a kind of preload.

Thanks for the info!

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Stronger with more coil compressed would mean they are progressive in rate. I am not sure what you mean by “bounce” once extended? The shock or damper should stop osscilation or “bounce”. Or you have some 100% stronger that you have tried and they come out of their perch? If the latter is the case can you find a shorter shock that stops this. On the Mira I used Hyundai Excel items to fix such a problem.

When going over bumps etc you hear the springs moving. When fully extended you can pull the springs out under the car (with force) without removing the shocks so the springs don’t compress enough under the weight of the car.

I’ve tried looking for shorter shocks but I think that the springs are just a bit to much. They almost don’t sag at all under the weight of the car and as soon as you put some weight on the rear seats everything is normal and no sounds are coming from the springs.

The springs never fell from under the car, and believe me I tried, so I think it’s safe. But it’s not something you’ll want to have in a daily.

That’s why we are searching for some other springs that will just fit like they should but still are going to be allot stronger.

So what I would guess is thinner and more coils. So the spring will sag more but will get stronger the more you compres it.

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Okay, springs not captive at full lower travel. Have you tried towing with these springs? Try an online spring calc and measure up what you have inputing the data. Measure some std and measure the problem ones.

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Never really tried towing with these springs but I think they would work good. But the car that is going to do the towing doesn’t have these springs since the people driving the towing car aren’t as young as I am :wink: So comfort is a bit more important than on my car.

I think the best way forward is by testing the different springs we have (original, lowering and the 100% springs) and determine if the 100% springs are just right or to stiff.

We hoped that there was a solution by keeping the comfort of the car relative good while also making sure that it can tow anything. So was hoping that there was someone crazy enough to already have that information ready.

I’ll keep you updated when we test the springs. And hopefully we’ll be able to determine what kind of strength we need.

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Also, good thing that I still have the data from when I calculated what springs I would need for my own car. At least now I can calculate what we need strength wise. Problem is finding the correct spring that will also work without the extra load without making noises when going over bumps.

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