General Auto Chat

Not sure if anyone here ever watches the TV series Engine Masters. They dyno test various domestic V8s to do comparisons between various components to see what works best and what doesn't work so well. Sometimes they come to conclusions that defy conventional wisdom. Even though my days of moding domestic V8s are well past for now, I really enjoy the series and come away learning something new almost every episode. It's is in its 7th season right now and worth checking out if you are a gearhead.

https://www.motortrendondemand.com/show/engine-masters/645/

 

Probably a mix of both, depends on the target audience for a car. Some manufacturers are happy to point out how much more rigid their latest chassis (basically meaning the unit body) is than the previous gen. If you drive a convertible vs a coupe model of the same car you can readily feel the difference chassis structure makes, even though they add a whole bunch of reinforcement (and weight) to make up for the lack of a roof. Even adding something like aftermarket strut braces can make a noticeable difference. In the end most people don't really care or want a super rigid chassis though.

 

Well now that I have come to think about it.. It could be somekind of resonance, even super low freq.. You loose feel of the car, because it isnt "concrete".. No other way to put it. We built Buggy chassies that are able to do 200 + km/h and they had relatively crappy suspension but they had that rigidness. Anyway.. that's my theory & subjective impressions.

 

This explains it quite well.

 

They also talk about peak horsepower, skidpad lateral Gs, etc. -- more numbers that, beyond a certain threshold, don't affect how my street car feels day to day. It's a lot like audio-gear reviewers talking about SINAD -- that number, if it's above some threshold of audibility, isn't directly related to what I hear.

It probably is. Torsional rigidity for street cars is now typically 10,000-20,000+ pound-feet or Newton-meters per degree or mm of deflection, whereas suspension springs typically compress a full INCH in response to only a few hundred pounds of force. Any chassis flexiness in a modern street car is going to be lost in the motion of the springs, the flexing/scrubbing of the tires, the compliance of suspension bushings, etc.

Chassis rigidity, beyond a certain threshold easily met by all modern cars, isn't really felt as "mushyness". It usually manifests as a car (usually a racecar or at least a street car modified for the track, with very stiff suspension and sticky tires) that doesn't respond to suspension adjustments. For example, stiffening the front swaybar should make the car understeer more, but it won't if the chassis isn't rigid enough to transmit twist between the front and rear axles.

 

I'll always be happy to have more horsepower or more grip, but agree that numbers are not everything that makes a car fun to drive. Cars like the Miata or BRZ are a good example. Not really special in any of the stats department, but widely regarded as exceptionally well balanced sporting rides.

 

Sharing this here because it's such a cool idea for a build. I spent countless nights in the late '90s staying up late watching speedvision coverage of old WRC, BTC and DTM racing, so this FCP Euro build is just so badass:



you gotta watch it all the way thru!

 

Came close to buying 2.3-16v in the mid 90’s, then the 97 Prelude dropped and I jumped on it… Beside those two cars, the only other car at the time that was in contention for my hard earned $$$ was the 300CE-24v.

 

I wished they'd used the M139 but they're likely pretty rare. The M133 they did use is plenty potent for a ca 2000lb car!

 

In other words, with a RWD setup, it all plays to the rear axle. Stiffening the front makes the rear relatively softer. Softer rear suspension puts down more power, therefore, more potential under steer. Ok, so if you had a moderately weak chassis it would be impossible setup the vehicle to behave in any specific way.

 

Traded in my '05 300C for this '21 Grand Cherokee today.




23k miles, owned by Chrysler as an executive lease vehicle. Tan interior, fully optioned except for the 18" wheels, which I prefer for the better ride and cheaper tires over the 20", and a pentastar V6 instead of hemi. I was surprised how fast this jeep is compared to my 300C. The 300hp V6 with the 8 speed transmission is more than enough to move this beast around.

 

SAY IT AIN'T SO!!!!

 

I didn't think I would ever sell that car, but the last year it has nose-dived in condition. Driveshaft was worn out, diff needed rebuilt, exhaust was falling apart, rear suspension needed rebuilt, everything inside was rattling, squeaking, etc. The only thing good about it was the engine and surprisingly no body rust despite spending 14 of it's 19 winters in Michigan.

 

Subaru failed by stupid driver attempting to descend icy hill road.

Spoiler

Wheel slightly askew after hitting curb.:



Next time chains or snow tires.

 

I have a set of summers and a set of winters on dedicated wheels and just swap them back and forth myself in the spring and fall. I try to err on the side of the winters, since driving on them in nice weather is obviously no big deal, but driving on the summers in the snow is white knuckle stuff. AWD gets it going OK. Braking and steering not so much though.

Good nobody was hurt though, that is what matters. Hope your car is back to normal quickly.

 

Hitting the curb resulted in a bent frame and some other messed linkage with an estimated bill of $5000 (includes new wheel). I conferred with my local independent mechanic and he says Subaru is not out of the ball park. My independent mechanic recommended using Subaru dealer for repairs for expediency. Parts cost would still be high anyway because new car so not much choice in sourcing parts other than directly from Subaru.

With our past cars we’ve always had 1 set of summer wheels and 1 set of winters. I thought I could get by for now with just all-seasons due to awd, then when the stock tires expire could switch back to having dedicated wheel/tires for the seasons. …

AWD does not help you stop, only helps you go. Ive owned an awd vehicle before so already knew this in practice but still foolishly underestimated the situation of trying to descend a steep hill in snow conditions. Expensive lesson (but couldve been worse like crashing into cross traffic). Next time Ill be prepared and/or turn around and use another route.

 

Does not take much visible damage to still end up very costly these days. Hopefully insurance will be covering it...

 

Nope. I fucked up. I put full coverage on wrong car accidentally. I put full coverage on my old VW instead of my new Subaru when I was using the Allstate mobile app. Probably had clicked on wrong vehicle profile. I wasnt careful and didnt double check. Stupid! Couldve been a lot worse than $5k is my consolation. Ya, Ive now reassigned full coverage to the correct vehicle. Triple checked and spoke with Allstate by phone to confirm.

 

Ouch, that bites. Makes it that much better that nobody was hurt though, so at least there is still that.

 

The rear passenger wheel was hit so hard that it put the front driver said out of alignment.

Good news is I have the car back and repair was $1k cheaper than estimated.