How well can you get a 2g GSX to handle?

[njshift]

I was doing some research on here and on the web for making a 2g gsx handle better. I am more concerned with the handling aspect of my car then straight line performance. I know steering and brakes have a whole lot to do with how a car handles, however I'm currently interested in the suspension aspects only.

Alot of suspension talk on here is limited to 1/4 mile/60ft performance and only a few threads on overall handling. I understand from the factory the gsx is heavy, the suspension has been improved form the 1g but leaves more to be desired, and the handling isn't superb. It is obviously not the most viable candidate to keep out with a porche on a mountan run. However, I think the stock setup did its job well on my car in stock form and wasn't half bad in doing so. Plus the all wheel drive makes up for alot! But, I have reached the limits of the stock setup and I'm looking for improvement. Now, with doing such things as stiffening the chassis w/ strut braces, doing some weight reduction, anti-sway bars, better shocks (coilovers.. ie jic and tein), wider wheels (17x8) and of course and most importantly great tires.. What type of handling gains will I expect? I know there will be improvement but will it all be significant? And of course different setups will yield different returns.

Does anyone have any type of measured gains of road holding (skidpad), slalom runs, high speed lane changes, quicker times on a road course?.. etc... Let me know what your setup is if possible so I can gain some more knowledge on this subject. With proper suspension tuning, can our cars run with or out perform better handling stock performing cars (ex. type r, ms protege, non sti impreza, 350z,vw gti, svt focus, srt4, se-r sentra.... these are ONLY examples, please don't flame me for this, I'm not an expert so I may be wrong). I'm not expecting the handling of an evolution but I don't want to be out handled by most cars in the twisties.. I know our cars are great 1/4 mile performers but can they be all around sick street/ some weekend-track cars?

 

[cait sith]

You really haven't looked that hard on the internet.

http://autocross.dsm.org

http://www.farnorthracing.com

Autocross.dsm.org seems a bit dated in some areas, but it's still a very good reference.

 

[njshift]

I am a member of [email protected]
I have used them for reference for many things. As you can tell or maybe not, I am doing research on this subject. Please don't make assumptions about who or where I received my information from. I am using dsmtuners as another method to get some good info..
And far north racing has a $custom$ setup that is completely unrealistic... Besides, their shocks are no longer being produced as per there website..If you are gonna respond, at least answer my questions (last paragraph)..
But I do appreciate your links and I'm sure many dsmers will appreciate them too. although they are not hard to find....
I'm looking for performance #'s and other useful information.. Thanks Greatly

 

[jtmcinder]

I have looked and have come to conclusion that what you are asking for doesn't exist on the 'net. There's plenty of butt-dyno data out there, some coming from people with pretty-well-tuned butt-dynos, but there's nothing like what you are asking for. Not even from RRE.

- Jtoby

ps. when I write "pretty-well-tuned butt-dyno" I mean a butt-dyno that has been tuned pretty well; I do not mean "pretty, well-tuned butt-dyno"

pps. I'm sometimes referred to as "calipygous" - not that you needed to know that

 

[njshift]

Thats somewhat of a dissapointment. Well I'm glad I'm not the only person who looked.. I was hoping someone possibly had some numbers of even lateral grip using a G-tech or some similiar device.. Well maybe someone will repsond with some positive information.....

 

[igs]

You can throw on slicks and have high lateral grip but your handling will still suck.

 

[njshift]

WOW.......
lets try to answer the questions I asked... but thanks for the bump...

 

[dsmturboawd]

imagine, a thread not staying on topic. now thats an unexpected occurance to get upset about.

 

[ahains]

Originally posted by njshift
Does anyone have any type of measured gains of road holding (skidpad), slalom runs, high speed lane changes, quicker times on a road course

I do not have any feedback for you, but I wanted to address the types of measurements you are looking for.
You probably already know this, but just to be sure:
(1)skidpad - this measures only how much grip your tires have, determined by the area of contact patch (size of tire and tire pressure) and stickiness of tire. Tells you absolutely nothing about suspension.
(2)Fast lane changes - very subjective, obviously. Presumably what would feel "good" for a fast lane change is if the car doesn't sway at all.. so the best setup for this test is an extremely stiff set of springs and dampeners. Not necessarily a "good" suspension.
(3)slalom - decent test, but again you can do well with too stiff of a suspension
(4)road course times - excellent test, but could be too stiff of suspension


Basically you are looking for the stiffest suspension that is not too stiff. Very unhelpful statement, I know

It sounds like you will be driving this car on real roads, correct? Not just race tracks? For real roads you probably don't want your fillings to pop out of your teeth if you hit a minor pothole.

So you want a high spring rate, but not TOO high. I recommend the book "How to make your car handle" for some guidelines on picking a spring rate for a given weight of car.. or what you are currently doing; find a well setup DSM and try to copy the best parts of their setup.

For a dampener (I guess 2Gs have shocks, not struts?) you want something well matched for your spring.. you don't want the shock to provide your ride stiffness if you can help it, you just want it to control the spring. Need an appropriate compression and rebound resistance.. both are settable on some shocks, or just one, or neither

You want the car as low as possible, for a low center of gravity. If you want to be able to go over speed bumps (I sure do), then don't go with the max drop available.

Anti-sway bars are great.. you want the chassis as stiff as possible.. I assume that DSMs are not known for breaking the mounting bracket off of struts.. or whatever they connect to on a 2G.

So this is probably not at all what you are looking for, since I don't have actual numbers for you. But maybe this basic info will help somebody.

I apologize for linking to another board, but I really do think this thread will be a big benefit to you:
http://www.dsmtalk.com/forums/showthread.php?s=&threadid=98687

HTH at least a little
-Adrian

 

[talonted_one]

I would like my 2G Talon to handle well, but I want it to Over steer more...How would I do that?

slide or die

 

[jtmcinder]

Well, stop and think about it for a minute.

If you want more oversteer, then you want to increase the front-to-rear grip ratio. You can do this by increasing front grip, decreasing rear grip, or both.

To increase front grip (when turning), you want to decrease the amount of front weight transfer. So you soften the springs and/or swaybars. You can also increase front grip by optimizing camber. This almost always means increasing front camber from what you have now.

To deduce rear grip, you do the opposite of the above.

When I had my 2G lowered about 1.5" with RM swaybars front and rear, 500/400 springs, and stock bushings with the upper rear arms spaced out a bit, I still had terminal understeer. So I upped the rear springs to 450 and added .75 degree more front camber with eccentric bushings. It felt undriveably loose for a few runs, but once I got used to it, it was much faster and a heck of lot more fun to drive. I wish that I'd made one change at a time, so I could say which was one important, but I didn't.

- Jtoby

 

[gotswrv]

Well, I tried to get a little info of the same nature off another board not to long ago. I was also told I suck. And then was told how wonderfully our car handle.
I have been wandering how the GSX/TSi's respond to a solid center diff? It seems to me that is is only considered for use in drag. I think it could help the car be more predictable. Right now I seem to go between under/oversteer without any regularity.
I understand suspension fairly well, but how to get the AWD to react the way I want seems to be a secret. As far as I can tell I have viscous coupling center, and open diffs front and rear.?. I am just guessing by how the thing drives. I have made no attempt to find info stating what is under there. (the TSi is the beater) And with the miles on the car (162K) any limited slips are gone.
I am very used to RWD and I can't stand FWR. I bought the AWD just so I could work on another project. And to have some experience with an AWD. Now (after a little ice and snow) I plan on keeping it around for quite some time. And maybe getting a second for the wife, as she also likes it.

Anyhow does anyone who like to turn the steering wheel have a solid center diff? What happens the the vehicle dynamics?

 

[jtmcinder]

Most 2Gs have boxes of goo in the center and the rear. Only the front is open. I would not advise going with a solid center because of what it will do in tight turns. When the car is turning, the rear tries to track inside the front. The center diff is there to allow this to happen. With a solid center, the rears will be turning too fast relative to the front. Yes, this can help break the rear free, but it also will bind up the front. Then, the unloaded insided front will break free, as a way to release the binding. So you lose the little help that you were getting from the inside front, putting more stress on the outside front, cooking this tire, and producing understeer. In summary, you bind up the car until something gives. Sometimes it's the rear and you turn. Sometimes it the front and you plough. The fact that this will be a guessing game makes it very hard to drive consistently at the limit.

What I really suggest is that you try out a variety of corner-entry speeds. Most of all, try entering a bit slower than you are now, maybe even trail-braking to get the rear end started, and then get back on the gas. If you find that you can't go WOT right after apex, then reduce your entry speed even more until you can.

Worst case scenario: if you find that you're having to stay off the gas until the corner is almost over, then you've got to change your driving style in the way I've described above. You can get rid of a lot of understeer by following the age-old advice: slow in, fast out. If you're already doing this, then think about shifting some more weight transfer to the rear. If you have RM sway-bars, there's enough room to drill new holes to stiffen the rear bar.

- Jtoby

 

[gotswrv]

Can I put thicker goo in my center and rear box's? Also is there a limited slip for the front that runs around $500?

I got the car a few months ago and at that time wasn't going to keep it more than a year. Now I'm plotting out the mods...
I don't really wanna lower it more than 3/4" and I need new bushings all around but I'm staying away from the urethane. I have no idea what to do for shocks... As for the stabilizer bars I'm not familiar with the brands in the "compact car" market. Since this seems to be a thread occupied by mostly intelligent persons, and RMs have been mentioned, then I'll assume they're of decent quality. Adjustable is also something I wanted.
I have a problem above 70mph though. BIG oversteer, especially if breaks are even thought about. The car stays neutral if full throttle is used.(Not always acceptable) I hope new bushings and an alignment will calm this. The car also likes to follow slush piles, alot, I recently found out.

Thank for the help,
Sam

 

[jtmcinder]

"Box of goo" is slang for viscous-coupling type LSDs. No, you can't change the goo, but you can spend $1000 for a Kaaz or a Quaife. However, you'd really want to do the front diff first.

There are lots of opinions to weed through on Kaaz vs Quaife; I've little experience in this area, so I can't help much. I've driven a 2G with a front Quaife and it seemed to be nice, but it required some changes in my style that I could make quickly enough. The owner of the car was planning to put in a Kaaz center.

There are only two OTS sources for sway bars for 2Gs: Susp Tech and RM. The RMs are better by an order of magnitude if you are going to use both. If you just plan to do the rear, then many people use the Susp Tech. But if you're already complaining about oversteer, this is not what you need to do.

What are your current spring rates?

- Jtoby

 

[talonted_one]

I'm just curious to why do some people use the ST rear sway bar over the RM? I have read up on both of them and it seems like the RMs are a more performance oriented set.

If I were to buy a rear sway bar right now I would be more inclinded to get the RM.Why wouldn't I want to do this?

 

[jtmcinder]

The ST rear bar is something like 24.5mm, while the RM rear bar is only 20.5mm. So, if you have FWD and really want to move a ton of weight transfer to the rear, the ST bar is the way to go. On an AWD, you don't want to run a bar this thick - you want to do more of the shifting of weight transfer using springs - because you don't ever want to pick up a wheel. (On a FWD, lifting the inside rear is no big deal.)

In general, when you look at the spring rates and bar thickness from Susp Tech, you see that they prefer soft springs and thick bars. Their replacement springs for 2Gs, for example, are actually softer than stock, while their bars are massive.

Most autoXers (in AWDs, of course) don't go this route. We use high-rate springs so that we can lower the car to get some camber. So we run bars that are only a bit thicker than stock. RM makes these.

This is all related to one of my pet peeves that you really have to plan what you're doing in advance if you want to buy only one set of parts and do only one install. If you fix the car piece-meal, you'll probably do everything several times. For example, you say to yourself: "self, I want to reduce understeer." So you thicken the rear bar. But it still understeers so you next try to get more front camber. This is best done by lowering, so you get some short, stiff springs. Combined with the stiff rear bar, you're now lifting the inside rear. So you have to soften the rear bar and then add some springs back there to get the car balanced again. By the time you're done, you're spending most of your time running eBay auctions, instead of driving.

- Jtoby

 

[talonted_one]

Ok thanks for the info. I see you have really done you homework on this subject.

Now for the question you really don't want to hear. I know many autocrossers don't like this but, I want to Attempt to drift my awd(stupid huh). What suspesnion set up should I look into to provide the oversteer needed to get the car sideways.

I have been looking into several coilover systems and have a decent grasp on their performance. I'm just lost when it comes to sway bars.

 

[gotswrv]

I am running stock everything as far as I know. Most likely, original everything.

As for drifting.. If you're not planning on driving on the street try unhooking the front stabilizer. Quick, easy, and free. Big body role though....

 

[jtmcinder]

I have no idea as to how to drift an AWD (on purpose), especially when it has a center diff of some sort. I'm sure it can be done - maybe a Scandanavian Flick combined with trail-braking(?) - but I'm not the one to ask. Not because I'm a snot about drifting; simply because I don't know.

- Jtoby

 

[MNGSX]

Those quaife and kaaz center diffs are nice for auto-x but a drag motor will turn them into magic exploding differentials.

There is a book out called how to make you car handle...

There are probably a few such books... Non biased or vehicle specific science on griping laterally in a very good way. They made a droped chevy pickup skid pad much higher than a stock C4 vette. It was something crazy like 1.25g's...

1. Good adj coil over shocks. Fully Adjustable valving
2. Upgraded swaybars front and rear. Get the biggest you can find.
3. STB's that work.
4. Accurately adjustable camber kits ft and rear.
5. Tires and wheels
6. Weight reduction and redistribution.
7. Very accurate tire pressure gauge
8. Infared thermometer for tire temp. Used for reading temp across the tread and adjusting pressure and alignment to make use of the full tread width under cornering forces.

They handle well in stock form... If modified correctly just as wicked as anything else.



Just like with engines it is alot of tuning. You cant just bolt it together and go..