2.0 vs 2.5 Coilovers

Fouledplugs

Fouledplugs

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Can anyone explain the pros and cons that exist between a 2.0” coil over and a 2.5” coil over? Or rather the difference between the 2.0 and 2.5 inch coil overs?

And has anyone been able to run the 2.5’s using full width axles (69.5” WMS) and sunk-in frame mounts? Is there enough room for packaging and tire clearance for up travel/full bump?

Keep in mind that I’m comparing 2.0” vs 2.5” from the same brand and both using remote reservoirs. Also worth mentioning, I would be hitting roads, interstates, and hardcore trails in the Jeep.
 
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Fouledplugs said:
Anyone?
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I'd say the main difference just depends on how much and what kind of high speed desert like driving you plan to do. A 2.0 can be made to work very well, even more so now I'd imagine as I think some are giving the options of putting the larger 2.5 resis on 2.0 shocks to help prevent cavitation.

I don't have first hand experience with those, but I do with just plain 2.0's in the front and rear of my TJ. My last trip to hammers I pretty much found the limit to my front 2.0's capabilities, couldn't put any more valving in without them cavitating on larger hits, though my 2.5's in the rear had a ton of potential left. Though I was still able to hit whoops at 40mph+ and a few jumps here and there.

I think the 2.5 springs are better about not bowing to the side and rubbing like some 2.0's, though that is more of a spring manufacturer quality issue and depends on how much use they get.

Hard to say what you really need, but knowing what I do now if I were to start from scratch again I wouldn't do anything less than a 2.5 for what I want to do. My next iteration of my TJ will have 3.0 IBP's in the rear and either 2.5's or 3.0 IBP's in the front as well

I am not nearly the most informed to answer your questions though, just a 23 year old with a half built TJ that likes to go fast
 
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Keep us posted - I have 2.5’s going on my V8 - and I know practically nothing about automotive coilovers .
 
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I run 14" King 2.0's on my rig, and I now wish I had done the 2.5's. Although it's not bad, I think the larger shock would control the heavy rig a bit better. In truth, it was fine until I threw a few hundred extra horses in there. The King's are adjustable, and since the Hemi I have had to turn them just about all the way up to control it when I'm going really hard on the throttle (which almost never happens...;)). It still feels like it needs a bit more. Live and learn.

The 2.0's were tough enough to fit, and 2.5's are that much more of a challenge. When I built the current suspension, I was sitting at about 66" WMS as I recall. But with your nearly 70" WMS my guess is that you could certainly get them to clear.
 
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Fouledplugs said:
Can anyone explain the pros and cons that exist between a 2.0” coil over and a 2.5” coil over? Or rather the difference between the 2.0 and 2.5 inch coil overs?

And has anyone been able to run the 2.5’s using full width axles (69.5” WMS) and sunk-in frame mounts? Is there enough room for packaging and tire clearance for up travel/full bump?

Keep in mind that I’m comparing 2.0” vs 2.5” from the same brand and both using remote reservoirs. Also worth mentioning, I would be hitting roads, interstates, and hardcore trails in the Jeep.
Click to expand...
How fast do you want to go?
How much weight do you anticipate carrying over the rear axle?
What shock shaft bias are you designing around?
Standard or adjustable reservoirs?
Who is doing your tuning?
 
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NashvilleTJ said:
I run 14" King 2.0's on my rig, and I now wish I had done the 2.5's. Although it's not bad, I think the larger shock would control the heavy rig a bit better. In truth, it was fine until I threw a few hundred extra horses in there. The King's are adjustable, and since the Hemi I have had to turn them just about all the way up to control it when I'm going really hard on the throttle (which almost never happens...;)). It still feels like it needs a bit more. Live and learn.

The 2.0's were tough enough to fit, and 2.5's are that much more of a challenge. When I built the current suspension, I was sitting at about 66" WMS as I recall. But with your nearly 70" WMS my guess is that you could certainly get them to clear.
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I suspect strongly that if you knew how to identify piston plunge, you'd already have the 2.5's on there or bottom fed shocks.
 
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NashvilleTJ said:
Please explain. Thanks.
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As Trevor explained, there is cavitation and then if the load on the shock gets higher, then the piston splits the oil column in the shock, creates a vacuum bubble on the lower side of the piston and then just shoves the piston into the reservoir. Essentially you are just blowing through the valving. That happens when you are asking too much from the compression stack. One way to test for it is to bump up the pressure in the reservoir and see if the squishy sound goes away. A shock shouldn't make any noise as it is cycled. One clue to piston plunge is sort of a squishy sound.

This video shows cavitation and how changing the pressure will stop the formation of the tiny bubbles.

 
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mrblaine said:
As Trevor explained, there is cavitation and then if the load on the shock gets higher, then the piston splits the oil column in the shock, creates a vacuum bubble on the lower side of the piston and then just shoves the piston into the reservoir. Essentially you are just blowing through the valving. That happens when you are asking too much from the compression stack. One way to test for it is to bump up the pressure in the reservoir and see if the squishy sound goes away. A shock shouldn't make any noise as it is cycled. One clue to piston plunge is sort of a squishy sound.

This video shows cavitation and how changing the pressure will stop the formation of the tiny bubbles.

Click to expand...
Thanks for that, Blaine. I've never experienced those symptoms - at least not enough that I have noticed. But I'm also not bounding across the desert. To me, it just seems a bit soft at times.

Merry Christmas. I hope it is an enjoyable one for you and your family.

Jeff
 
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NashvilleTJ said:
To me, it just seems a bit soft at times.
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Again, if you are hitting events either large enough or fast enough regardless of any bounding through the desert, the symptom of not enough shock or too much valving is the perception of being a bit soft because they are bottoming out too easily. With the weight you're running, I can't even imagine trying to make a 2.0 work.

If you can get around a nitrogen set up, bring up the pressure some in the reservoir and see if the perception of a bit soft changes going over stuff that you are familiar with.

Merry Christmas to you and yours.
 
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mrblaine said:
Again, if you are hitting events either large enough or fast enough regardless of any bounding through the desert, the symptom of not enough shock or too much valving is the perception of being a bit soft because they are bottoming out too easily. With the weight you're running, I can't even imagine trying to make a 2.0 work.

If you can get around a nitrogen set up, bring up the pressure some in the reservoir and see if the perception of a bit soft changes going over stuff that you are familiar with.

Merry Christmas to you and yours.
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I do have a nitro setup. I'll give that a shot - Thanks.
 
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Trevlaw said:
A 2.0 can be made to work very well, even more so now I'd imagine as I think some are giving the options of putting the larger 2.5 resis on 2.0 shocks to help prevent cavitation.
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This was my end result after doing further research with my current YJ build.

I love the performance gains from the 2.5's. It will just give me a reason for another build one day,

NashvilleTJ said:
The 2.0's were tough enough to fit, and 2.5's are that much more of a challenge. When I built the current suspension, I was sitting at about 66" WMS as I recall. But with your nearly 70" WMS my guess is that you could certainly get them to clear.
Click to expand...
Packaging is always gonna be the issue, I wish now that I went wider with my axles.

mrblaine said:
How fast do you want to go?
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Some sreet driving as well as some fast off road stuff.

mrblaine said:
How much weight do you anticipate carrying over the rear axle?
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Not much, maybe a 20+- gallon fuel cell and a 40-42' spare.

mrblaine said:
What shock shaft bias are you designing around?
Click to expand...
50/50 would be ideal.

mrblaine said:
Standard or adjustable reservoirs?
Click to expand...
Adjustable.
 
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