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-   -   handling changes w/ stripped int and stock suspension (https://www.rx7club.com/race-car-tech-103/handling-changes-w-stripped-int-stock-suspension-796516/)

rxtuner79 10-26-08 10:50 PM

handling changes w/ stripped int and stock suspension
 
I recently hit a pole with my S5 NA and bent a tie rod and end. I have a depowered S4 rack with super angle tie rods and Super*Now adjustable ends (figured I might as well upgrade since I'm replacing them). But when the rack goes in the front sway bar has to come out so I'm going to replace it. I don't want to the front without the back, then I need endlinks, and might as well do bushings as well, etc.

So to get to the point, while I'm saving up to get the car driving I'm stripping out the interior and doing any other labor that doesn't cost money. Right now it is completely stripped with just two seats, a wheel and shifter. I'm making a new dash board (alum or cf) with guages for speed, rpm, temps, etc and have all of the sound deadening removed. I haven't done any reduction to the engine bay yet so I want to know (while I'm still on stock suspension minus sway bars, endlinks and bushings):

1. How will this affect the balance of the car?
2. How will this affect the handling and braking?

Will it be safe to drive it without adjustable coilovers to compensate for the change in weight distribution?

My current mods are a rebuilt/streetported S5 13B, Fidanza 8lb flywheel, convertible wheels, TII brakes front and back with stainless lines, and Bridgestone Potenza RE01-R's. I'm still a very novice driver and looking to get some driving experience through autox and hopefully get to race on some road courses and hillclimbs in the future so any help, opinions, or advice would be appreciated. Thanks.

Gene 10-27-08 08:58 AM

I don't think you need the super angle kit unless you're drifting, which I doubt you're doing with no PS.

If you're planning to actually race the thing you need to figure out what sanctioning body and class you want to run it in, as some various mods may be verbotten (like ripping out the whole dash!) If you're just putting together a car for HPDE that's another matter, a stripper NA with the right reliability mods (big radiator) will be an excellent no-hassle driver's ed car. That's probably where you need to be as an amateur driver, I don't recommend trying to actually race until you have a few years of DE under your belt. You certainly don't need to spend money on more power right now, the best use of your dollars to go faster is to improve the nut that holds the wheel.

Living in PA you're in a good neighborhood for this, there are NASA and other clubs running all kinds of driver's ed events at Pocono, BeaverRun, Summit Point, and the new place that just opened up in Millville NJ (New Jersey Motorsports Park)

Autox is a good starting point because it's so cheap, but the downside is that you don't get so much track time in a day. NASA is trying to get new people in, to do this they offer what they call "hyperdrives" at just about every NASA race/HPDE weekend. $50 gets you a 20-ish minute run group on the track with an instructor, and while you're there you can watch races and DE, and wander around the paddock ogling race cars and talking to people.

Yanking a bunch of weight out shouldn't affect the handling drastically at street speeds, just stay away from the limit, but remember the car will ride higher, and the FC has a lot of negative camber gain when you lower it, especially in the rear, so the opposite is true as well. The raised ride height will add positive camber, and can cause misbehavior. Removing your front bar may adversely affect handling, but a lot of people (me included) remove the rear bar on their track car and never look back.

Speaking of which, replace your DTSS bushings if you haven't already.

Hit me up on PM or in this thread if you have questions about events in the area. The season is just about done, but things will be getting interesting in the spring.

rxtuner79 10-27-08 09:22 AM

The super angle kit was already puchased when the GB went up, so I figured it couldn't hurt to buy them. Drifting is most likely not an option.

I'm not really looking to get into competitive racing... I just want to be able to race the car without the risk of killing somebody, so I guess class doesn't really matter. And I agree 100% on the nut behind the wheel. That's why i would like to start off slow with autox and work my way up from there.

I live about 15 minutes south of Philly, so the autox locations are pretty convenient for me right now... The only other place I really heard about was Millville because my mechanic (JPR) is in South Jersey. I will have to do some research on those other places.

I did notice a good amount of change in the ride height, but as of now I don't have to money to do anything about it, so that's why I was just making sure it would be ok. The car will rarely be driven on the street except for taking it to events so I'll make sure not to push it too hard. I will be buying adjustable endlinks with the bars so hopefully I can make them work well. If not, I'll just remove the bar.

The DTSS bushings are another thing I will be doing but forgot to add it to the list.

Thank you for all the information. I'll definitely let you know if I have any questions.

Gene 10-27-08 03:09 PM

Fair warning, taking your car to the track is expensive. Since you have an NA the gas will be cheap, but you still have (short list)

Motor oil
oil filters
brake pads
brake discs
brake calipers (!!)
tires

etc etc... I have several bins of spare parts that I bring with me to the track.

rxtuner79 10-27-08 03:29 PM

It hasn't been too expensive to track it, but I definitely see how it can be very expensive.

I will be replacing the oil/filter before I get it driving again. I just had my calipers rebuilt about two weeks before the crash, so they should (hopefully) be good. The pads are crap so I was planning on getting new ones anyway, and the discs are also new. The tires only have a couple thousand miles on them. I should be good for at least a couple autox events, right? I want to stick with the low-speed stuff until I get proper safety equipment and better suspension for the road courses.

Gene 10-27-08 08:05 PM

You'd be surprised how much you can learn with the crappy suspension. One of the most educational track events I ever attended was with a rented Pontiac Grand Am when my own car was in the shop.

Black91n/a 10-27-08 08:34 PM

Stripping the interior will tend to take the weight off the rear axle more so than the front, which will make the rear act stiffer, making the car more prone to oversteer than before.

You don't really "need" aftermarket endlinks, I got by fine for a few years with stock endlinks on RB bars.

I ended up tracking my car when it was 99.99% stock and it did just fine. I never actually had overheating problems despite tracking it numerous times with the stock radiator, including a couple events with 2 drivers. The NA FC makes a really good learning platform. The main cost from tracking is the desire to go faster, so you start upgrading the car more and more, at least that's the way it's been for me.

Gene 10-27-08 09:10 PM

The main benefit of the aftermarket endlinks is that you can make sure there's no preload on the swaybar, but it might be a while until he's into that level of preparation.

j9fd3s 10-28-08 11:34 AM

yeah if it was my car, id just put the rack in and go racing. eventually you want to upgrade the front bar, but its not really needed, so why wait? especially if you're just starting out.

the driver has more impact on lap times than ANYTHING else you do to the car. improving the driver is also one of the cheapest mods you can do.

when you start going to the track you'll see theres no shortage of high hp fully prepped race cars that arent very fast, cause the driver isnt that good. i could give TONS of examples, but this weekend at the track we were watching an e46 m2 with 650hp loose to an e36 m3 with 300hp. the guy in the 300hp car was just a better driver.

rxtuner79 10-28-08 12:44 PM

Yeah, high HP is definitely not a goal of mine. I have 150 at the wheels now, and that was dyno'ed with just the flywheel and port. The exhaust was stock minus a crappy catback the PO put on, and the cats were removed by a jackass at the local muffler shop since then. I would like to to a standalone w/ ITB's and custom exhaust to shoot for about 200 rwhp, but that will come after the suspension work and some more experiance. After that's done I'm going to slowly build a bridgeported motor and would love to get 300 rwhp, but realistically shoot for 280 and if I get to the point where I need more I'll probably just put a small turbo on it. But that's after I get a LOT of experience.

The reason I want to do the endlinks and sway bars now is because I don't want to waste money later installing things that could be done for free now. My money situation isn't too great and I don't have the facilities to be installing this stuff myself. I'm just trying to knock it all out in one shot. Plus, the car is just going to be sitting up the street until spring anyway (no place else to keep it, unfortunately).

I definitely want an aftermarket radiator. I've never had problems either, but better safe than sorry.

The responses are greatly appreciated... Keep 'em coming!

j9fd3s 10-29-08 11:40 AM

sway bar is 8 bolts.... steering rack is another 8 bolts.... rack you can definately do without even jacking the car up.

you're talking about maybe an hours worth of work tops

Black91n/a 10-29-08 09:39 PM

I don't know about that, all the bolts are from below and you've got to get the plastic undertray off too. I've taken my rack out twice already and I did it from below both time, I can't immagine doing it with the car on the ground. While it might be possible, it's probably faster and easier to go to the extra effort to jack it up.

rxtuner79 10-30-08 09:08 AM

My friend's brother is a mechanic so he told me to get all my parts together and we can take it to his shop one weekend when he doesn't have the kids and we'll just throw everything on there. That's most likely how they will be getting installed, but it won't be free. That's why I would rather do it all at once.


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