DG suspension setup for street

[PEGE]

So I am building a setup same as the recommendations in Denis Grant's website.
-Koni yellows
-koni sleeves
-spherical bearing top plates
-Hyperco springs


Question is:
I run my car on the street and would like to go to a softer front spring (thinking 500 front / 400 rear)

Does any one have a setup of the sort, that drives there car on street and track.
This setup is for lapping.

Any advice experiences?

Thanks!

 

[UofACATS]

400 rear

On a 2G, that's about as high as I would go for the rear spring. I wouldn't pair 400 rear with 500 front under any circumstances, including the street. I wouldn't recommend 400 rear for what's implied when you say "setup for the street" either.

FYI, the ots GC setup comes with ~ 500/250.

A heavy rear spring is more uncomfortable than heavy front, in my opinion. Adequate dampening (which you'll have) paired with (non)low-profile tires is a recipe for a pretty good ride on the street. I have no issues with my setup on squishy Kuhmo MXs.

 

[PEGE]

^thanks

Anybody running these setups and like or dislike certain spring rate combinations?

 

[PEGE]

Nobody here has a similar setup and run on the street?

I was looking to get some feed back or pointers from more experienced lappers.

 

[Ludachris]

I run 500/400 and Konis on my 1g road race car, and have driven it on the street. It's actually not all that bad, but then again, I'm not necessarily the guy to talk to for a "comfy" ride. I probably wouldn't want to drive the thing everyday due to it having fixed seats, no A/C or heater, no stereo, and very little interior trim.

RRE likes running 400/500 on the 1g to get the car to rotate more in the turns. But again, that's a racing application. For a good street car I'd probably consider running 300-350 lb springs in the rear (if it were my car) if I weren't going to track the car much.

 

[PEGE]

I run 500/400 and Konis on my 1g road race car, and have driven it on the street. It's actually not all that bad, but then again, I'm not necessarily the guy to talk to for a "comfy" ride. I probably wouldn't want to drive the thing everyday due to it having fixed seats, no A/C or heater, no stereo, and very little interior trim.

RRE likes running 400/500 on the 1g to get the car to rotate more in the turns. But again, that's a racing application. For a good street car I'd probably consider running 300-350 lb springs in the rear (if it were my car) if I weren't going to track the car much.

Thanks for the input.

I think I will be running 500F / 350 rear.
I only drive it about 3 times a week.

If anyone else has recommendations, I appreciate any experience with similar setups.

 

[Absit]

Autocross to Win (DGs Autocross Secrets) - Dynamics Calculator
Everyone's got goofy NF's around here..

 

[UofACATS]

Thanks for the input.

I think I will be running 500F / 350 rear.
I only drive it about 3 times a week.

If anyone else has recommendations, I appreciate any experience with similar setups.

Is there a reason you want to run such a high rear vs. front rate for a "street" setup? 350 rear pairs better with ~700 fronts.


In fact, as I mentioned in my earlier response, it's "adequate dampening" you should be after, not low spring rates. I'll quote someone else..

Harshness is mostly a function of the damping (shocks).

Until you get to super-stiff springs, the ride of a car with Konis depends on the rear springs, not the front.

More...

There's no reason to expect stiffer springs to increase *harshness*. If the car is properly damped, you can run very stiff springs without shaking your kidneys to death. IT'S SO BOUNCY!!! is usually a DAMPING problem, not a spring problem

Although Ludachris gave you the 500/400 number, we have to remember the differences between the 1G and 2G motion ratios, rendering a direct comparison between the two as less than optimal.

Here's a real-world example in a 2G:

The 500's in my front do seem a good amount softer then the 350's in the rear. I don't mind the 500's in the front at all for the daily driver but sometimes find the 350's in the rear abit on the firm side.

and here's why..

Because the motion ratio (the effectiveness of the springs) is higher in the rear than in the front, the rear is more sensitive to spring changes. Again, as a general rule of thumb, 100lbs of rear spring equals 300lbs of front spring in terms of effect on natural frequency (the car is also nose-heavy which further contributes)

...

the motion ratio on a 2G DSM can be approximated at about 0.75 on the front, and 0.86 on the rear.

That being the case, we immediately know that we're going to need more spring on the front in order to match the rear.

key word being "match."

 

[Ludachris]

Nice way of explaining using all those quotes. Well done.

 

[PEGE]

Thanks again UofACATS, great reading.

I see what you are saying about the f/R spring weight ratio.

The reason I want to run 500 in the front is that from what I have read, anything over 500 "you should revalve the shock"(konis). I am not at that point yet.

I am a recreational driver. Use to drag race and now I have gone lapping with some local car club members and got hooked.

I wouldn't mind going heavier in front since I read this makes the car have a lot less understear, but I don't want to revalve.
Looking for testamonials confirming that running over 500 front is somewhat street "confort" compatible and had no valving issues, and I'm not to picky with confort.

I am trying to gather the most info before getting the springs, to try to get a "good strarting suspension" to learn off of.

Thanks for the help guys!

I should be receiving some goodies soon (machined top hats with spherical bearings), I will post pics as I build the setup!

 

[PEGE]

Got my top plates with spherical bearings this week end.

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[Ludachris]

Got my top plates with spherical bearings this week end.

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Where are those from?

 

[4g63monstr]

+1 Where from and how much? These look nicely made. How much did this whole setup cost you? I have been looking at running this setup for awhile now.

 

[PEGE]

I'm up in Canada, these parts are made buy a company in Niagara Falls, called RTM Racing.

The setup from the picture cost 550CDN$

Here is a link, I think he mentioned these might be his last set(they are built to DG's specs):

https://www.rtmracing.com/xcart/product.php?productid=17204&cat=855&page=1

The quality is great!

Should be getting my shocks and sleeves soon.

Not ordered the springs yet, still trying to pick my starting setup!
Don't be shy to share your spring rate experiences and thoughts on street and srtip handling.

 

[PEGE]

I replaced my rear bushings, they where pretty worn.

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Quick sanding and repainting of the upper control arms.

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[a95gsx]

I am running 550/275 on my 2g with qa1 shocks all around with ride height near stock. The resulting ride is fantastic - even on the pot hole filled stadium truck like tracks that the city of Birmingham calls roads. The car does have a healthy push at the limit but still corners fairly well. Now that it isn't my daily driver I am thinking of upping the rates to 600/325 or 650/350. I will need to keep the same ride height to handle the pot holes.....which isn't so bad cause I still have a camber curve with all my travel.

BTW I've got the same brake setup from RTM you'll love it.

Keep in mind the 1G and 2G have completely different suspensions and will not share the same spring rates....

 

[jtmcinder]

Those plates look suspiciously similar to RRE plates, right down to the color and extra holes for other fitments.

In any event, don't be afraid to go a tad higher in the rear with Koni Sports. The valving is highly digressive in bump. I ran 650/425 on a street-driven 2G and loved it. Just don't drive around with the rebound cranked up or you'll start packing down and then the ride becomes awful. A half-turn off full soft in the rear and it's wonderful.

- Jtoby

ps. +1 on the differences between 1Gs and 2Gs; different motion ratios; not really comparable

 

[Dallas J]

My talon was daily driven by me, and now DD'd by another with 700/350 springs on koni yellows with a full prothane kit and home made DG style upper hats. Autocrossed that car and tried a ton of different rates and it works very well with that setup. Though its very limited if running stock diffs.

Ride is alright if you keep the rebound around 1/4 turn from full soft, but the koni's arent known for being soft. 500/250 would be really decent for a street only driven car. If you want high rates and comfortable ride you have to go to a quality monotube. My evo is DD'd with 10k/12k (560/680) spring rates and its far smoother than the talon is. Im about to jump to 12k/16k though so I doubt itll be like that too much longer .

 

[PEGE]

Thanks a lot for the great advice guys.
I am ordering the springs today.

 

[a95gsx]

Thanks a lot for the great advice guys.
I am ordering the springs today.

sooooooooooooooooo.........

what'd you order?

 

[PEGE]

sooooooooooooooooo.........

what'd you order?

I`m going to try out 600F / 300R
I'm having trouble finding stock for the sleeves, everything else is ordered.

I removed all non suspension related posts

I will post a build blog later.

 

[greengoblin]

Cool parts but this was really a suspension thread. You should start a build blog.

Kevin

 

[PEGE]

Cool parts but this was really a suspension thread. You should start a build blog.

Kevin

Thanks.
I think I will do that.

 

[snowborder714]

As Kevin mentioned, this would be much better in the blog section. It will be easier for you to document your progress and everyone to follow it, instead of wading through a whole thread to find your updates.

You can easily turn any post into a blog entry by clicking the little icon (guy with a speech bubble) in the bottom right corner of the post.

Let me know when you're done and I'll clean this thread up so anyone in the future won't have to sift through all the random stuff to get to the helpful info.

 

[knochgoon24]

I have 600F/350R on my car and I wouldn't mind a bit more rear spring. I think a bigger rear sway bar would also help without having to add more spring.

I usually put 12-14k miles on my car per year. I have almost 5,000 miles on my DG setup and I'm loving it. The differences at the autocross were night and day.