LLave Posted November 3, 2009 Share Posted November 3, 2009 So i have changed direction with my Z, I have come to realize a real track car is not in order. I need an aggressive street car / light track duty. The car will be SBC powered, sectioned struts, minimal interior, etc. Here are the undecided items. Roll cage, i have my main hoop and door bars done and i do place a high value on the added safty. But i am concerned about the safety factor on the street (ie helmet-less). My tool box area was all cut up from the previous owner so some sort of chassis bracing will be necessary. Front frame rails, I bought the material to fab new front frame rails but i am wondering if that is really necessary on a hot street car. They are not rusted out. Perhaps it is just a waste of time to fab new ones. What do you think? The car will be getting Bad Dogs. Poly bushings vs Heims on control arms. I was planning on doing some sort of heim joint TC rod and control arms. But i do have a set of ploy bushings. Are heims a bad idea on the street? Help a brother out. What to do? What to do? Quote Link to comment Share on other sites More sharing options...
EMWHYR0HEN Posted November 3, 2009 Share Posted November 3, 2009 Roll bar at the most for street use. If your frame rails are in good shape no need to change them. A nice triangulated strut brace will help significantly. Definitely the frame rails if it's an early s30 and maybe the floor pans if their rotted. On the street I would try and minimize the number of heim joints used. Quote Link to comment Share on other sites More sharing options...
V8ZRACER260Z Posted November 3, 2009 Share Posted November 3, 2009 Well you have a few questions to be answered. As for the roll bar and street use the most important thaing is that you head (helmetless) can't come in contact with the roll bar while seatbelted. Adjust you seat and always pad any area close to your head as an added saftey precaution. If needed redo your roll bar to prevent contact. The tool box area can be reinforced by adding a bar across behind the seats or getting a donor tool box section from a car beyond repair and restoring the original tool box. As for the frame rails the stock rails do not need to be reinforced with a SBC of streetable HP. As long as they are solid they will do fine and with the bad dog subframe should be more than substantial for street use. On the last question poly bushings are much more street friendly. Heim joints will transmit alot of road feel and noise thru the chassis mre than you would want for frequent use. The resonse if any you would gain by using them would be minimal for a street car. Heim joint are primarily degigned for track only cars where noise and vibration ar part of the game and the need for presise adjustments paramount to consistant lap times. On the track the few tenths you pick up from them are big but on the street its anoying at best. Hope this helps if you have any other questions just ask. Rick Quote Link to comment Share on other sites More sharing options...
AkumaNoZeta Posted November 3, 2009 Share Posted November 3, 2009 When it comes to hiem joints I've heard people that use them didn't notice any ride harshness, only more road noise, and even that was marginal. Quote Link to comment Share on other sites More sharing options...
EMWHYR0HEN Posted November 3, 2009 Share Posted November 3, 2009 If the roads are smooth then yes probably just pick up more noise with the heims but, when you go over the rough stuff it gets bad. Even a set up road markers will jolt up your spine. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted November 3, 2009 Share Posted November 3, 2009 Do an X from the rear strut towers to the base of the hoop. That should take care of the package area being damaged by the PO. I drove my car with heims jointed front LCA's and TC's and monoballs in the camber plates daily for years. Only issue I had was loose camber plate monoballs in the rear really make a racket right behind your head. I had 3/4" rod ends on the TCs and they were probably due for a change after 5 years on the road. The LCAs were 5/8 but newer but didn't need to be replaced during the several years that I used them daily. Quote Link to comment Share on other sites More sharing options...
johnc Posted November 3, 2009 Share Posted November 3, 2009 Let's step back a bit. How much track driving experience do you have? The reason I ask is that building a fast street/track car for a pro race driver and a regular Joe on the street is very different. A pro driver can work very well with a car that is less forgiving while the regular Joe needs a car that has a margin of safety to save his ass from stupid mistakes. Quote Link to comment Share on other sites More sharing options...
LLave Posted November 3, 2009 Author Share Posted November 3, 2009 Do an X from the rear strut towers to the base of the hoop. That should take care of the package area being damaged by the PO. I drove my car with heims jointed front LCA's and TC's and monoballs in the camber plates daily for years. Only issue I had was loose camber plate monoballs in the rear really make a racket right behind your head. I had 3/4" rod ends on the TCs and they were probably due for a change after 5 years on the road. The LCAs were 5/8 but newer but didn't need to be replaced during the several years that I used them daily. Sounds like you have quite a bit of experience with heims on the street. I have heard from some people about issues of stress cracks at the suspension pick up points due to heims transmitting more vibration to the frame.... which i am not totally sold on. Did you feel the performance benefits outweighed the negatives? Quote Link to comment Share on other sites More sharing options...
LLave Posted November 3, 2009 Author Share Posted November 3, 2009 Let's step back a bit. How much track driving experience do you have? The reason I ask is that building a fast street/track car for a pro race driver and a regular Joe on the street is very different. A pro driver can work very well with a car that is less forgiving while the regular Joe needs a car that has a margin of safety to save his ass from stupid mistakes. Excellent question. In all honesty... I need that margin of safety. Most my experience is has been in a lightly modified 2005 STi that was pretty damn forgiving. How exactly would the set up very if you were building a car for a pro vs a rookie? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted November 3, 2009 Share Posted November 3, 2009 Sounds like you have quite a bit of experience with heims on the street. I have heard from some people about issues of stress cracks at the suspension pick up points due to heims transmitting more vibration to the frame.... which i am not totally sold on. Did you feel the performance benefits outweighed the negatives? There was one post here where someone suggested that you should really check your chassis for stress cracks WEEKLY if you are running heims. My opinion is that is BS. I did have a crack in my frame, but that looked to me as though it was due to the PO running over a curb (frame rail was really badly dented and floor pushed in a bit on that side). No cracks in the strut tower, crossmember or TC buckets on my car after 40K miles on heims 6 seasons of autox and a bunch of track days. You need to take care of your own car and be responsible for your own decisions, but the idea that using heims tears up the car is counter to my personal experience. In light of the way I used the Z I think it was well worth it to run it on the street with heims. YMMV depending on what you're planning to do. If you're just driving to work and home it might be money that you get better return on with engine mods. Quote Link to comment Share on other sites More sharing options...
johnc Posted November 3, 2009 Share Posted November 3, 2009 I agree with Jon regarding the rod ends/heims and chassis stress. I would not recommend rod ends on a primarily street driven car just from the standpoint of maintenance and inspection. They do require more attention then poly or rubber bushings and a higher standard of fabrication/installation. For my own street Zs I do not install rod ends except for the anti-roll bar end links. IMHO, you won't be able to take advantage of the additional precision that rod ends give - at least not at this point in your driver development curve. As Jon suggests, the money would be better spent elsewhere. Regarding front frame rail stiffening - only do that after you've built a nice triangulated front strut tower bar setup and installed the Bad Dog subframes. The lower part of the engine bay is stiffer then the upper part, so increasing stiffening at the top is more important. Quote Link to comment Share on other sites More sharing options...
AkumaNoZeta Posted November 3, 2009 Share Posted November 3, 2009 I have another question for Mr. Mortenson, you said the heims were due for a change after 5 years or so. How do you tell? Do they just start looking bad or can you feel it while driving? Quote Link to comment Share on other sites More sharing options...
LLave Posted November 3, 2009 Author Share Posted November 3, 2009 Thanks it sounds like i may be sticking with my urethane bushings for a while. As far as the engine bay bracing I was planning on doing a strut tower bar that made a triangle between the struts and the firewall. Then possibly an x brace connecting the front frame horns to the struts, if i can fit it around my motor, which will be placed as close to the firewall as possible (SBC, no distributor). JohnC what type of modifications do you recommend against for the stupid mistake inclined? I would really like to end up with a car that works well for ME. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted November 3, 2009 Share Posted November 3, 2009 I have another question for Mr. Mortenson, you said the heims were due for a change after 5 years or so. How do you tell? Do they just start looking bad or can you feel it while driving? My TC rods weren't so bad you could feel it while driving, although I suppose that could happen, probably hear a clunk when you went from reverse to 1st gear. There was some galling on one of the rod ends and it was really up inside the joint so you couldn't see it, but if you took it off you could feel that it was pretty tight to move. The other side was on the loose side, with just a hint of play in it. I think to inspect them you can feel play by jiggling the suspension, but if you wanted to find that galled monoball you'd really have to take the suspension apart and move it by hand. Quote Link to comment Share on other sites More sharing options...
LLave Posted November 4, 2009 Author Share Posted November 4, 2009 I dont mind inspecting the car every now and again but i think i will stick with urethane. Though I do recall someone suggesting that rubber should be used in the TC rod to allow enough free moment. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted November 4, 2009 Share Posted November 4, 2009 Poly in front, rubber in back, or all rubber. Or get the G machine aluminum/nylon ball socket setup and put rubber on the back of that. Quote Link to comment Share on other sites More sharing options...
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