1g Suspension Plan with a few questions. Please revise. (First suspension setup)

[BoostedBeaver]

Ok so I have been reading a lot of information on shocks and springs. I have read the information in the following threads and from DG's website.

Autocross to Win (DGs Autocross Secrets) - Suspension
http://www.dsmtuners.com/forums/handling-tech/169955-how-plan-your-suspension-upgrades.html
http://www.dsmtuners.com/forums/frequently-answered-dsm-questions/169437-suspension-faqs.html Every link
http://www.dsmtuners.com/forums/articles-suspension-brakes/386735-suspension-springs-understanding-terminolgy.html

Of course there where words that I had to read 2 and 3 times to pronounce right, but I made it.

This car is being built towards drag racing. While it does see the occasional Friday night or weekend drive during nice weather, it is not my DD. I am not worried about how stiff the car may feel or about how low I can drop it. I just want to purchase a product that is going to have some longevity to its life and a decent performance record. The overall goal at this point is to max out the HX35 in a straight ¼ mile strip.

The next topic that will need to be discussed is my budget. I will say that I am not prepared to spend the 2-3k on Variant coilovers. I have looked into Koni’s and GC coilovers (DG Coilovers). This will put me at the 1,000 dollar mark, so at this point, that is the amount I am looking at spending. Hypercoil springs are also an option that I am pursuing but can always be swaped in later.

At this moment I am intending on getting Koni yellow’s for a 1g AWD. Of course, these have been discontinued and are no longer available in the rear. Thanks to talonDSMerr and this thread http://www.dsmtuners.com/forums/articles-suspension-brakes/406746-2g-rear-koni-shocks-1g-awd.html we know that the 2g AWD Koni will bolt in and make you have an effective 1 inch drop due to the difference in shaft length.

Will this have any ill effects on some geometry that I am not aware of??? Lowering the front GC coilovers should get the car back to somewhat being balanced… Correct??

Next up would be the GC coilovers. The spring rates are the main concern at this point. Like stated above I have read a lot of DG’s information, but it is based on a 2g. He does state that a DSM is typically a 60% front 40% rear bias when it comes to corner weighting the car, but all other measurements (such as the motion ratio) are not the same on a 1g. How could I somewhat calculate spring rate to accommodate my situation?

My car weighs 3021lbs without me in it. I weigh 167, so 3188 would be the final weight give or take a few. With the general rule of 60 front 40 rear that puts me at 1912.8 front (956.4 each corner) and 1275.2 (637.6 each corner). Now there is suppose to be other things factored in such as motion ratio that I do not know. If you have any input this would be helpful and much appreciated.

I am open to other setups and love to entertain Ideas. I also need to know about top hats (Stock suitable) and Torrington bearings (where to purchase and comments) Camber plates/bolts(when they become needed). I have also been following the http://www.dsmtuners.com/forums/handling-tech/420528-bilstein-hd.html thread, but I do not have the equipment or the fab skills to tackle a project like this at the moment.

So overall this is what I am looking at and I just need the help from the knowledgeable members on this forum to make an educated decision on my first suspension setup. I am not trying to make this rocket science, I am just trying to accomplish a task with the knowledge that I have found. I am not as fortunate as some (snowborder714 http://www.dsmtuners.com/forums/blogs/snowborder714/3043-new-suspension-corner-balance-alignment.html) but would love to do the best I can with what I have and knowledge that I can obtain. Sorry if this post seems like a lot, I am just trying to make my goals clear and concerns known. Please let me know if there is anything I missed and thanks in advance for any constructive criticism and/or suggestions.

Robert

 

[92 GSR-4]

Haha, you've researched the exact same sources I have, and are asking the same questions I have. I'm glad to see I'm on the right track.

An additional question I had was concerning the valving of the 2G Koni Rears vs. what the 1G model had. I'm guessing it wasn't much different either but it would be nice to know. I'm also in for the torrington bearing answer!

 

[BoostedBeaver]

I recall this being asked in another thread that I read, but do not remember an answer. I will see if I can find that thread again, but I have read so many it may be a little difficult.

Robert

 

[GSLENK]

The only thing I would be concerned about is lowering ability and camber adjustment to compensate for lowering. I've read that the koni/gc isnt too lowering friendly, but Ive seen pics of cars running that combo and really low. I wonder if they are messing stuff up.

About rates... Idk.

 

[BoostedBeaver]

The only thing I would be concerned about is lowering ability and camber adjustment to compensate for lowering. I've read that the koni/gc isnt too lowering friendly, but Ive seen pics of cars running that combo and really low. I wonder if they are messing stuff up.

About rates... Idk.

Do you have any links to the threads that state this lowering issue above?? The lowering will only be done enough to try and balance out the car. The camber adjustment can be made via the plates and/or bolts. The only thing I wonder is when do these become necessary?

Robert

 

[leepen]

1g Konis are out there for the rear AWD..I just got mine this week..tho hard to find
EDIT: Ive read 1.5 inch is ok for lowering and I to would like to know spring rates for a drag car/occasional call out..on the GC site it asks what you plan on doing racing wise with the car..but Id perfer to know some spring rates
EDIT EDIT..what setting should I have the rear Konis set at..I dont want to take them out after they are installed (you have to remove them to adjust them in the rear)

 

[eclipsh]

If the 1g Koni's are the same as the 2g units adjusting the rear can be done in the car. The adjustment shaft pokes through the top of the shock shaft just like it does in the front. You just have to pull the covers off above the shock towers which is few seconds worth of work.

A 1" drop in the rear only needs a small drop in the front to set a 1g nice and level. They are typically raked a bit from the factory so the rear is a little higher. You may wish to keep that stance for drag racing since it should help the anti-squat system in the rear work a little better. One thing that isn't mentioned on your reading list is the factory Technical Information Manual (inside the DSM TECH folder if you have the factory manual on CD). It explains exactly why the suspension is built the way it is. Good information to have when you're planning on tweaking it.

For drag racing you typically run higher rates in the rear. I'd suggest checking the 1/4 time slips and see what the 1g guys in your target range are running.

 

[BoostedBeaver]

1g Konis are out there for the rear AWD..I just got mine this week..tho hard to find
EDIT: Ive read 1.5 inch is ok for lowering and I to would like to know spring rates for a drag car/occasional call out..on the GC site it asks what you plan on doing racing wise with the car..but Id perfer to know some spring rates
EDIT EDIT..what setting should I have the rear Konis set at..I dont want to take them out after they are installed (you have to remove them to adjust them in the rear)

A link to where you found a new set of Koni's for the rear would be nice. I know that they can sometimes be found used, but at this point I am looking for information on the pro's and con's of the 2g rear Koni's in a 1g since they are readily available.

Your first edit says 1.5in is ok, but does this still allow room for camber adjustment. I know you run out of adjustment at some point, but I do not know if this is vehicle specific or a general rule based on certain measurements of our suspension components? Also the amount of lowering will only be done to improve the performance.

As far as spring rates and shock adjustments, please read some of the links in the opening post. They will provide you most of the information to answer those questions. GC will also help with selection of spring rates if you give them a call, but this is a very general selection.

Robert

 

[Calan]

Robert...

I didn't see it mentioned, but I would seriously look into the active toe eliminator kit that Jay Racing sells. It takes a lot of that unpredictable dynamic toe and squirly-ness out of the rear end.

I'm not sure how useful it would be for drag applications, but it certainly seems that my car is more planted in general. It's a subtle thing, but noticeable.

Don't forget the impact that all of the bushings have, specifically at the rear sub-frame and front k-member.

 

[BoostedBeaver]

If the 1g Koni's are the same as the 2g units adjusting the rear can be done in the car. The adjustment shaft pokes through the top of the shock shaft just like it does in the front. You just have to pull the covers off above the shock towers which is few seconds worth of work.

A 1" drop in the rear only needs a small drop in the front to set a 1g nice and level. They are typically raked a bit from the factory so the rear is a little higher. You may wish to keep that stance for drag racing since it should help the anti-squat system in the rear work a little better. One thing that isn't mentioned on your reading list is the factory Technical Information Manual (inside the DSM TECH folder if you have the factory manual on CD). It explains exactly why the suspension is built the way it is. Good information to have when you're planning on tweaking it.

For drag racing you typically run higher rates in the rear. I'd suggest checking the 1/4 time slips and see what the 1g guys in your target range are running.

Thanks for the suggestion of new information. I do have the downloaded manual at the house and I will take a look at that tonight.

Running higher rates in the rear is what I do not understand. The front weighs more than the rear so the same rate spring would actually be much stiffer in the rear (or softer in the front, however you choose to look at it). So with a higher rate spring in the rear, that would make it extra stiff. I do appreciate your input and understand that the rear springs would aid in "anti-squat" but how much is to much?

Robert

 

[BoostedBeaver]

Robert...

I didn't see it mentioned, but I would seriously look into the active toe eliminator kit that Jay Racing sells. It takes a lot of that unpredictable dynamic toe and squirly-ness out of the rear end.

I'm not sure how useful it would be for drag applications, but it certainly seems that my car is more planted in general. It's a subtle thing, but noticeable.

Don't forget the impact that all of the bushings have, specifically the rear sub-frame and front k-member.

Craig,

I will look into this toe eliminator kit and I will have to read a little bit to understand its function but that is fine.

Thanks to finding your build thread (in the old section) a while back, I was motivated to do my whole front end while the motor was out. This included Prothanes for the sway bar, sub frame, control arms, etc. I have since purchased rear Prothane sub frame, sway bar, and mustache bushings to go in with the suspension. This will also be coupled with a rebuilt drive shaft (JNZ kit) but that is another thread to come. Any other suggestions or maybe some sneaky bushings I may have missed?? Thanks for your input Craig.

Robert

 

[Calan]

Any other suggestions or maybe some sneaky bushings I may have missed?

Sounds like you pretty much have it covered.

What are you going to use for rear upper control arms? I've been running Ingall adjustables for the last 4 years or so and they have worked fine for me... but I'm not sure if they are still available. There are probably better ones out there now.

How about sway bars? I'm not the guy to ask as far as suspension calculations go, but I went with an RM rear bar and trashed the stock end links. Here is a link to what I ended up building, in case you're interested: http://www.dsmtuners.com/forums/art...om-awd-rear-sway-bar-links.html#post152189652

 

[BoostedBeaver]

Sounds like you pretty much have it covered.

What are you going to use for rear upper control arms? I've been running Ingall adjustables for the last 4 years or so and they have worked fine for me... but I'm not sure if they are still available. There are probably better ones out there now.

How about sway bars? I'm not the guy to ask as far as suspension calculations go, but I went with an RM rear bar and trashed the stock end links. Here is a link to what I ended up building, in case you're interested: http://www.dsmtuners.com/forums/art...om-awd-rear-sway-bar-links.html#post152189652

Craig I will take a good look at the link that you posted when I get home ("work" ends shortly) Thanks for that information.

I honestly was not aware that the upper control arms needed to be changed. Does this help to adjust camber and toe??? What other purposes do they serve??? I will do a search when I get home because I have apparently overlooked some things.

With sway bars, I had read a lot of what DG published and the effects of roll bars. They transfer the weight to certain tires and as far as I understand more bar is not always better. They can aid in over steer/under steer, at least that is my understanding. I had no plans to get larger bars, but again I may be badly mistaken some of this information I am reading.

Sway bar end links are something that I have not looked into either. I honestly overlooked them. I am sure your article will shed some light on this subject but any other questions I will mention later.

Of course all of DG's stuff is at a professional level and I do not believe that I will ever push this car to those limits. I am a spirited weekend driver (when weather permits) around town and love to make those 1/4 adrenaline runs on the weekends. With that said I may be way to "anal" about the setup, but I just want to make an educated decision. If your article answers any of my questions, I will read the answers shortly and edit this post so no need to retype it. Again thanks for the info and I will be reading it in a bit.

Robert

 

[Calan]

Cool.

You probably already know this, but I would also search for posts by jtmcinder, ACM, and pagosa_dsm. Those guys are all very knowledgable on suspensions and have posted a lot of very good info over the years. Snowborder714 has also done a lot of research on suspension setups lately and has several posts on the subject. He's focused mostly on 2G's I believe, but I'm sure a lot of it crosses over.

Oh yeah... while everything is apart, don't forget to show the wheel bearings some love if they need it.

 

[BoostedBeaver]

Calan,

that is a nice writeup on the hemi joints. How have they held up over time? I am sure they have worked well since you recommended them. I will give this a look while I am down there. Once I finally get my suspension planned, all this information will be great.

I knew about jtmcinder, but not the other two members that I can recall. Thanks for that too.

If the wheel bearings look anything like the fronts,

Bad Wheel Bearings 1990 Talon - YouTube

I am sure they will need some lovin while I am down there.

Robert

 

[Calan]

I haven't beat the hell out of the car on turns, but the end links have held up great so far. If I was going to auto-x or road race it often, I probably would have gone with the stronger heim joints...but these seem to do the trick for a weekend warrior/DD.

 

[eclipsh]

For a drag setup bigger sway bars aren't likely to help. Sway bars come into play in cornering. Also, by going with stiffer springs you reduce your need for stiffer sway bars.

My earlier comment about stiffer springs in the rear was meant as the ratio front to rear. Normally you do run stiffer springs in front and less stiff ones in the rear. I've seen drag cars run rear springs that are just as stiff or more stiff than the front. How much is too much depends on you. As you increase that rear spring rate vs the front you're going to make a car that has a looser tail in corners and one that will ride like crap. On my 1g I had 450/350 spring rates and it was very firm, fairly neutral in corners, easy to trail break when I wanted to and it didn't squat too bad (for me) in a straight line launch. That said, I prefer turning the car over launching it. It was also unpleasantly stiff to ride in for long distances and my wife didn't care for it much.

As Calan said, call GC when you're ready and they'll suggest a good rate combo. I'd also check the 1/4 time list as I suggested earlier and see what the drag racing crowd is running.

Also, if you put your car on a big diet you'll need less spring and, of course, get all the other benefits of weight loss.

 

[RamenPride]

If the 1g Koni's are the same as the 2g units adjusting the rear can be done in the car.

Rear Koni's for the 1G had to be taken off of the car to be adjusted. That's why a lot of people went with Koni's in the front and AGX's in the rear.

 

[BoostedBeaver]

For a drag setup bigger sway bars aren't likely to help. Sway bars come into play in cornering. Also, by going with stiffer springs you reduce your need for stiffer sway bars.

My earlier comment about stiffer springs in the rear was meant as the ratio front to rear. Normally you do run stiffer springs in front and less stiff ones in the rear. I've seen drag cars run rear springs that are just as stiff or more stiff than the front. How much is too much depends on you. As you increase that rear spring rate vs the front you're going to make a car that has a looser tail in corners and one that will ride like crap. On my 1g I had 450/350 spring rates and it was very firm, fairly neutral in corners, easy to trail break when I wanted to and it didn't squat too bad (for me) in a straight line launch. That said, I prefer turning the car over launching it. It was also unpleasantly stiff to ride in for long distances and my wife didn't care for it much.

As Calan said, call GC when you're ready and they'll suggest a good rate combo. I'd also check the 1/4 time list as I suggested earlier and see what the drag racing crowd is running.

Also, if you put your car on a big diet you'll need less spring and, of course, get all the other benefits of weight loss.

Thank you for your input. I have been looking at that list and viewing members that are in the mid to low 11's. Almost all that I have viewed do not state spring rates. In fact a lot of people in this range are running stock suspension according to their profiles.

Sorry about the misunderstanding with the "stiffer springs" comment. I just misunderstood what you where trying to say. The information about the car becoming loose in the corner is good to know. I do not want the car to become a "hazard" so to speak when I do drive it on the street.

The squating is a big concern for me. Maybe my old worn out suspension is really working against me and giving me the false idea that I need large spring rates to compensate. My car (at a 4500 RPM lunch building 10lbs or so) will squat to the point where the front tires start to spin. The front right is first followed by the front left in most cases. I am suffering 2.1 + 60'. I did cut a 2.09 once but that is nothing to brag about. I am trapping 126mph and can not brake 12's.

I did call GC and we are going to talk some more and get things wrapped up tommorrow. Thanks again for sharing your information and any other suggestions are welcome.

Robert

 

[leepen]

A link to where you found a new set of Koni's for the rear would be nice.
Robert

It wouldnt do any good, I got there last 1 and they found the 2nd at some distrubiter. I googled "1G rear Koni" the first 3 where vendors here the 4th is where I found my set, shouldnt be to hard