This kind of explains what I've been saying for a long time based on personal experience of the negative performance aspects of lowering a car like the TL. It's nice to see it in writing.

http://www.fromsteve.net/tech/Bump-S...wering-Springs


If all you care about is looks, go for it. If you care about performance, you're destroying it by lowering it. The proper way to lower a car like the TL is not to do it with springs. What we need is a shock with a shorter body.

Our cars sit extremely close to the bumpstops when stock. With my a-spec springs it was touching the stops just sitting idle. I cut my stops but I'll probably be looking into firmer shorter stops for the future. They would be very easy for me to make. You can't truly "tune" a suspension like this unless you live in an area without a single bump and even then it's iffy. Everytime it hits a bump spring rate more than doubles. When it leans into a corner which ever end hits the stops first will skid.

The guys running soft lowering springs are really screwing things up.

It looks as if the bumpstops may play a role in spring rate in daily driving which is completely wrong for both performance and comfort. I have no idea why manufacturers consider this acceptable. We need at least 3" of pure spring compression with the bumpstops completely out of the picture. This would especailly help stability while hitting bumps mid corner and with passengers in the car. With a major change to the stops or the shock body we could increase both comfort and performance.

For the time being, I think I'm going to modify my Konis to get the same ride height I have now but with them on the upper perch. I should be able to gain 3/4" of suspension travel while maintaining the same overall height of the car.

 

As always, I find your technical insight quite exciting. I presume you're going to post about this? Looking forward to it!

 

Yep. I'm very excited to start trying this. I have so much experience with my current setup. I feel that I know exactly how it performs and feels in just about every scenario. The first goal is to modify the Konis to sit 3/4" down in the lower control arm and then raise the spring perch 3/4" to get the same over all car height but with more suspension travel.

I think this will really give TL owners something to look forward to as far as street performance is concerned and with better ride quality too. Unfotunately I have to work all week plus the weekend but sometime late next week, maybe Thursday evening, I should have it done and preliminary results in.

 

Happily subscribed. GL with the approach, cap'n.

 

nothing wrong with ss teins with a mild 1.7 drop right?

 

No worse than anything else but yes, there's a problem with any drop that's done with springs only or Konis that lower the spring perch (same thing as springs). Even a-spec was just a few tenths off of the bump stop.

Unless the Teins have a shorter shock body from the lower perch to the lower mounting point they just increase the problem.

 

they are coilovers

 

If the height is adjusted by moving the lower spring perch they will put it closer to the bumpstops as you lower it. It would also depend on the starting dimensions so I can't for sure say they're bad without measuring. Did you by chance take a look at them as you started lowering the car down after install?

In the future, I have a design in mind that will retain full factory suspension travel while lowering that's fully adjustable, but first I'm going to test this simple mod out to see how I like it.

 

i dont know. marcus at heeltoe set it for me. on finger gap around

 

I just searched and found one coilover set for the TL that offers separate height vs spring rate adjustment. This is what I'm talking about. These things can lower the car without affecting suspension travel. Most of the ones I found in my search reduce travel while lowering the car.

I've actually got something in mind that I can't believe has not been produced before yet all of my searches turned up nothing.

 

I used to own a '92 Integra (DA) and its front suspension was plagued by very short shock travel from the factory, so using any sort of lowering spring/coilover setup reduces shock travel to basically nothing and it'd be riding on the bump stops at rest. There were guys on the other Honda forums that were able to increase travel at the top hats and/or modifying the lower control arm.

IHC, are you effectively trying to slide your front Koni further into the lower control arm? I'm very intrigued to see the results. It's been done on Civics/Integras, but I don't think there have been many guys that have attempted it on their TL/Accords. Also, if we remove the strut tower brace, we could probably squeeze out 1/2"-3/4" by modifying the top hats. Although I'm guessing removal of the strut tower brace is introducing body flex.

http://www.d-series.org/forums/diy-f...-travel-2.html

 

That's pretty much what I'm going to do. Adjust height the right way while having no impact on travel.

I've been searching and have found one coilover set that allows height without affecting travel. I've found one set that start off at a slightly better point but then get closer to the stops as it gets adjusted lower.

I may even take it a step farther and try and get just a little more travel than stock.

Interesting to hear that other Honda suspensions have been modified to take care of the issue. I've never done any research before this.

 

hmmmm interesting. Im dropped about 2-2.5 inches all around with megan coilovers. I also have the dampening set to very stiff. I can feel every bump in my lower back lol. But the car feels much tighter and there is very little body roll around corners.

So if Im hurting performance like you suggest, what exactly am I hurting? Straight line acceleration?

 

You'll probably have to completely remove the brake line bracket as it's in the same place as the notch that seats into the LCA. The more I look at it, the easier it looks if you whip a grinder out.

Sorry for the poor image:

Picture from honda-tech forum of Civic LCA/Koni:

 

If I am understanding the article and explanation correctly, It is affecting the ability of your suspension to aid in handling over any impact that the suspension would normally absorb from a bump or any case.

The suspension has an area before the bumpstop is compressed that is relatively (compared to the bumpstop) soft and easily compressible, this area is what allows your suspension to absorb shock (say from a bump) without jostling the entire car.

Meanwhile the bump stop is extremely firm and does not compress in shape easily allowing it to carry harsher stresses in the event the suspension's strut is compressed all the way to the bumpstop. However because the bumpstop is firmer the impact will be transferred to the car's chasis propelling it upward when impacts (from bumps not a collision just to clear that up) and causing changes in center of gravity which alters inertia and creates lessened handling.

This information is detailed more in the paragraph after the graph of the compressability of a strut with lowering springs and I am mostly summarizing.

 

That's exactly it. You want the springs to control the suspension and body. The bumpstops should only be used in a severe impact to keep the suspension from damaging itself. It looks like many cars are using the bumpstops as a dual rate spring.

Just a note, some of the coilovers do it the right way and some don't.

 

That's what I'm talking about! This initial test is so easy I can't wait to try it. I pay attention to every detail so it should be fairly obvious if it makes a good difference. If it does, I'll be working on a much better version.

 

Great explanation

Which coilovers would that be?

 

If you can increase shock travel by 3/4" at the lower control arm, and then move the Koni spring perches from the lower setting to the stock setting, you've increased travel by almost 1.5 inches while maintaining the same lowered ride height that you're at now. IHC, I know you've figured this out already - I'm just thinking out loud. If you have the proper tools, you should be able to machine additional grooves onto the Konis for the perfect ride height. I haven't examined the stock shocks or A-Spec shocks yet, but if I remember correctly, it'd be a more difficult task to do the mod at the LCA.

 

I'm already in the planning stage. I have full access to a CNC shop from a friend. I haven't been this excited about a suspension mod in a long time. If I get it done and it seems to work, I'll do it for free for a couple people that want to try it and review it.

 

Please put me on the list. I am definitely interested. If very similar and possible, I'd like to use my A-Spec shocks. If not, I could probably cough up $275-$300 for front pair of Konis. Getting front Konis set on lower perch reduce front height slightly has always crossed my mind, but I knew it'd be at risk of reducing travel. This is why I haven't gone that route.

 

I remember why it's more difficult to gain more suspension travel using stock/A-Spec shocks by using the mod to shock sitting in fork/LCA mod. OEM shocks don't have removable spring perches, so the only gains would be reduction in ride height while maintaining stock shock travel. This is good but wouldn't benefit someone looking to increase their travel.

 

Would the Koni SP3's shorter shaft have any positive effect on the suspension travel with the choice of different lowering springs?

 

Only if the shock body is shorter from the bottom perch to the lower mount and the bottom perch to the top of the shaft is stock length or greater.

 

Man I am sure glad you posted this IHC. I have lowering springs only, and wasn't informed on how bad it was to have my setup. I was looking into getting the koni yellows, and now this makes getting them a high priority. Thanks for the useful information!

 

Ok, sorry for the noob questions, but what would the benefit be of the shorter shaft on the SP3's be vs. the sports? Also, what if the bumpstops were removed? I have read before that some don't use the bumpstops with the Koni's, wouldn't this be a negative (as far as performance)?

 

Tein dampers have a compeletly revised tube length and stroke to handle lowering the car with proper travel maintained. Likewise they utilize a new bump-stop that is less than half as long as the OEM ones in the front and more in the rear.

There are a few systems that have independand height and pre-load actually, not the least of which is the HT-Spec damper system, which I actually had a chance to install Saturday and evaluate the first version of! Click here to read my notes:
https://acurazine.com/forums/3g-tl-tires-wheels-suspension-97/ht-spec-tuning-function-form-type-2-damper-tl-specific-application-771156/


We used to do this on the older Civic and CRX models form 84-87. Those cars have a real problem with suspension travel. It works, but I really do not recommend it. Until recently the best solution was to run shocks that were modified with shorter bodies. Recently we came out with a damper system that I helped engineer with Tein USA and co-branded as the Medieval-Pro damper kit.

Our new concept for the TSX and TL takes more into account the needs of TL and TSX customer by coming out with the afore mentioned HT-Spec damper kit that will give all the travel one could want, even at 2.5" drop levels.


IHC, you can send your Konis to Truechoice and they will perform the shortening for you as needed, but this process WILL reduce your ride height unless you are willing to run a high rate of preload.

 

so which ones would be better Tein SS or Megan Racing? or either of the 2

 

Good info! Thanks. I'm working on something special right now. It will probably take a while but it's going to be pretty neat for Koni/stock/certain coilover users.

While modifying the design, might as well shoot for more travel than a stock TL.

Very interesting to know that some people already modify the Konis. Do they modify the entire lower body?

 

Yes, contact Truechoice. They have been shortening Konis for us old CRX folk for at least 2 decades. They can shorten the tubes and the shafts to convert it to a true short damper. I hesitate to remove the brake line bracket since it provides a nice stop for the fork.

For lowering the Megans are better and for quality the SS are. We are working hard to split the difference with our HT-Spec kit.

 

Marcus has new information regarding the upcoming TL HT-Spec suspension. Suspension travel has been addressed:
http://www.heeltoeauto.com/pitboard/?p=504

 

Very Interested in what your doing. I would love to test if you end up making the brackets. I have neuspeed sport springs with koni yellows and progress rsb, so im running close to the same set up as you OP. Keep us all updated!

 

^I have the same set-up. Also interested in seeing results.

 

F2, Megan, D2, BW Racing, AMR...... these all have height adjustment built into the shock body, meaning travel of the strut is not affected. Spring pre-load does not change, either.

Whereas Tein and some others.. there is no pre-load on the springs. You just drop down the spring perch height, and the strut has to stay compresses to fit whatever height you set the springs at.

 

subscribed

 

Does anyone have info on H&R coilovers if they offer separate height vs spring rate adjustment. I just installed a set of H&R coilovers on my car.

Love to hear more info and which coilover is better.

 

Glad i got the ss teins

 

Should be very interesting to see how this works out. Best of luck, and subscribed

 

Noob alert.

Question: Read the article, and went over the comments again. Much more insightful, but have you taken wheel gap into consideration? How does the distance between the top of the tire and bottom of the fender compare with the distance between the bump stops and shock body at idle (i.e. amount of suspension travel)?

This is a bigger issue with those who run lowering springs with bigger wheel/tire combos, as many people do. Like one person mentioned above, they've got a one-finger gap between the top of the tire and bottom of the fender.

If you lower the car with just springs, you shorten the distance between the bump stop and shock body, meaning less travel BUT you're also shortening your wheel gap.

Wouldn't that be a valid reason for having shorter suspension travel? As bad as it is hitting bump stops, it's even worse to rub, because then you get the same centre of gravity and intertia problems, but you're also ripping off chunks of $200 rubber.

Of course, the solution to this would be to just have stiffer springs, but customers want a "softer" ride.

 

what about H&R Racing Springs with Koni Shocks