johnc

This is where common sense lets folks down. Most engine compartments are designed to flow air through it while the vehicle is moving. Each vehicle is different but I saw some measurements of underhood air temps on a 1999 Ford Contour SVT that showed where the aftermarket cold air intake was located (behind the battery on the left side) the air temp was only 10 degrees warmer then outside the car if the car was moving over 20 mph. YMMV...

On a race track (admittedly a pretty artificial environment) a good driver can turn a faster lap with the ABS off in almost all cars (the Z06 Corvette is one exception that I know of.) ABS induces understeer in a turn and its often hard to feel exactly when the ABS is going to kick in. ABS also pretty much kills brake pedal feel. In the rest of the world you're not going to beat an ABS equipped vehicle especially if you have the presence of mind to try and steer away from the wreck as your foot is hard on the brakes. ABS systems do some funky things once in a while. At a number of autocrosses I've seen the ABS systems on late mdoel Camaros go into something called "Ice Mode", which basically means you have no brakes until you settle the car and let it coast for a second with your foot off the brakes. This usually happens during hard left, right, left, right transitions under braking (like a decreasing slalom). Steve Eugina's Camaro rolled off the course at 20 mph into a small ditch with him yelling the whole way, "I got no brakes!" When the car finally stopped, he had brakes. We gave him crap about it for months afterwards.

Lowering the car is not really the issue, the original design with the rubber bushings works through the entire range of front suspension travel. The culprit appears to be the additional defelction force required by poly bushings. It adds more stress into the TC rod and causes a failure IF there is a stress riser somewhere on the rod that concentrates force. One preventative may be to shot peen and polish the TC rod removing all sharp edges.

I would listen to Eddie. Sometimes us so called "experts" tend to want to do things the way we've always done them. That's until some upstart beats us and then we have to rethink what we thought we knew. Regarding the relationship between the tire and wheel. I spent some time talking with Jeff Speer at Hoosier and he expalined that sidewalls on radial tires should be as close to parallel as possible. This allows the sidewalls to flex in sync (sort of) and keeps most of the tread in contact with the ground.

A hypothetical conversation with an insurance claims adjuster after the accident: Adjuster: So, explain to me again how that part of the vehicle came apart. Gluer: I bought this space age epoxy and used it, very carefully according to the instructions, to glue the chassis together. Adjuster: Wasn't it spot welded from the factory? Gluer: Yes, but welding causes weakness and you can burn holes through the metal. Adjuster: And when did you receive your mechnical engineering degree? Gluer: Huh?

A 315 should be on a 12.5" wheel and a 335 should be on a 13" wide wheel if you're considering performance. Rim width should be equal to section witdh to get the best performance out of the tire. A 285 width tire ideally should be on a 11 to 11.5" wide wheel.

Just ignore the guy.

I used the term "improper modification" above. I should have just said "modification."

The above statement by me was wrong... improper modification was not the right term. I should have just said modification. And I didn't know the car was a 280ZX, so there may be differences on how the TC rod is stressed compared to a 240/260/280.

True if you dont know what you're doing. False if you know how to weld. Go look at any new vehicle (except the aluminum chassis ones) and see how they are put together. Its only recently that various types of non-welding attachment have been used and only for joints that are designed for that type of attachment.

That setup has been used since the 1950s on many, many vehicles around the world. Its simple, cheap, and strong. The tension rod is only a fore/aft locator for the lower control arm. It comes into play primarily under braking and most of the time just goes along for the ride. The failures we are discussing are the result of improper modifications and/or a lack of inspection. What many people forget is that modifying a vehicle to perform beyond its design requires more frequent inspection and maintenance. I've yet to see a tension rod failure on a competitive ITS 240Z and that's a result of frequent inspection and replacement as necessary. BTW... the ITS racers put far more load into the suspesnion then any street driver 240 ever sees.

You've got way too much spring in the car! On my race 240Z I run 275 front and 300 rear srpings with a 23mm front and a 17mm rear anti-roll bar. For a street/autox car reduce your spring rates to 200 front 225 rear, keep the anti-roll bars that you have, buy a set of Tokico Illumina shocks, and get 4 of the same tires all the way around. Once you've done the above, then start figuring out the car's handling. Right now, unless you have a 10 point welded in roll cage, your chassis is moving and causing your suspension to do odd things.

I run a 275 on a 10" wide wheel so a 285 should fit fine on an 11".

By itself, lowering the Z doesn't induce additional loads into the TC rod beyond what it was deisgned to handle. The increase in deflection force that poly bushings require push things over the design limit for the TC rod and if there are any stress risers, the failure will start there. The one poly bushing suggestion is a good preventative measure because it resuces the deflection force increase by about 50%. You might still be exceeding the deisgn limit but failure should occur later in the fatigue cycle. FYI... I both poly bushings race 240Z but disassemble and check the front suspension annually.

Great car! I autocrossed a 1991 NA hard top for a year. As with any mid engined car, they have a low polar MOI which means its hard to get them to oversteer, but once they do you need fast hands. As long as your son knows what to do and reacts immediately he should be fine. They are easy to drive at the limit and clearly communicate what's going on with grip. Don't overheat the car, watch the front anti-roll bar mounts, careful witht he 3rd gear synchros, and the exhaust systems rust out easy. Also, they don't need as much tire as others. Its easy to "overtire" the car and create unpredictable handling. Same is true with springs and shocks. Think "supple", not "stiff." Locally Eric and Mari Clements are thinking about selling their ES national championship 1991 MR2. I've been seriously thinking about buying it but I need yet another car like a need a hole in the head.

And my reply answered just that. Basically you are building in a LOT of understeer by running stickier tires on the rear. Since the Zs chassis has understeer designed in from the factory, why would you want to significantly increase it? I'm sure it would come back to bite you on a rainy day or in an emergency situation.

> I could see where the grip would be an issue > on the track, but what about the road? Grip is grip regardless of where you are.

About $450.00.

Maybe the shipping cost of $65 includes insurance? Maybe it includes the cost of a box and some packaging? Maybe it includes the cost of him taking the stuff to a Mail Boxes Etc.? Why is every vendor trying to rip you guys off? Makes me not want to do work for HybridZ folks...

Ya know Terry, I try. Sometimes I wonder why, but I do. Which one? A 280Z or a 280ZX? They are two completely different chassis. The 280Z is the same chassis as the 240 and 260 only a little stiffer. The 280ZX is a different chassis based on the 200SX and the 810.

How did they screw you out of $43? That money went to the shipping company, Top End sure didn't get any of it. Are they charging you shipping to return the parts to you?

SPD sells mild steel or stainless 2.5" 45, 90, and U bends on a radius as small as 2.5". They aren't the cheapest but they have great service and stuff's in stock all the time. (888) 778-3312.

Seam welding the car with 1" welds spaced about 1" apart throughout all the body seams (after spending hours cleaning all the crap out) will do more to stiffen a Z chassis then most anything short of a welded in roll cage. Its a long, dirty, tedious job but its worth it after you've had a few weeks to get over the hell it puts you through.

Always remember that the terms "bolt-in" or "bolt-on" really means that you'll need a $2,500 TIG welder, a $5,000 lathe, and a $10,000 mill to actually install the part(s).

Ultimately, the decision between the early Z and the ZX comes down to your own style preference. Which one do you think looks better. Whichever style you go with, the decision over which model year should be based on how clean (rust free) the vehicle is. For a V8 conversion I would much prefer a rust free 280 shell over a lighter, rusty, 240 shell, if those were my only two choices. The same is true when looking at ZXs.