Suspension Tuning For Engine Swaps

[darcey]

Hi,

I’m currently looking into an engine swap for my car and was interested in tuning the suspension to suit the new power plant.

I was wondering if anyone knows if there are any formula or rules which should be applied when setting up the suspension for a car with an engine transplant? For example…for every KG of extra weight you will need another kg per mm in your springs…etc.

The car is a laurel and I’m looking at either an SR or RB25 conversion…at the moment I’m leaning more towards the SR (got a bunch of bits for the SR and heard it gives better weight distribution due to the engine position and light alloy block)

Cheers

[Scooby]

not sure that there is a simple direct relationship, wheel ratios play too much of a part in this. how much weight difference are we talking? you could start probably calc a start point by knowing the wheel ratio, spring rate and weight over the front axle and comparing it to a car that has similar attributes but it'd be a lot of stuffing around to find that 'other' car. if it's a small weight increase see how it drives and then make adjustments accordingly. alternatively do the conversion, find out what the weight is over the front axle and then compare to another car - easier this way but i'm hoping there's not mnuch weight difference.

[Sydneykid]

Hi,

I’m currently looking into an engine swap for my car and was interested in tuning the suspension to suit the new power plant.

I was wondering if anyone knows if there are any formula or rules which should be applied when setting up the suspension for a car with an engine transplant? For example…for every KG of extra weight you will need another kg per mm in your springs…etc.

The car is a laurel and I’m looking at either an SR or RB25 conversion…at the moment I’m leaning more towards the SR (got a bunch of bits for the SR and heard it gives better weight distribution due to the engine position and light alloy block)

Cheers

<{POST_SNAPBACK}>

Oh, if only it were that simple, but it isn't. The best method I have found is to look at what similar models, with similar suspension layouts have with those mechanicals. That gives you a starting point, then you look at what you are going to use the car for and calculate the upgrades from there.

Most people just stick the mechanicals in and see what they end up with. THne talk to a suspesnion expert. Since you are looking at a marginally lighter engine this would be my suggestion in your case. If you were looking at a substantailly heavier engine you might not be able to do that, the nose would simply drag on the ground.

Bottom line, I wouldn't worry about it until you have worked out exactly what it is you are going to do. If it is a lighter or similar weight conversion, then just get on with it.

Hope that helps

cheers

[darcey]

cheers SK...I'll drop in the SR and see how i go

thanks again