Everyone always talks about the MacPherson struts in the DC5 being inferior compared to the suspension setup in the DC2. I was just wondering why MacPherson struts are bad and if anyone had any hard evidence on why they are supposedly inferior?

Note: If this came up as a flame in any way I apologize in advance. In no means am I trying to start a flame war between the RSX/Integra.

 

MacPherson struts have some pretty notable disadvantages when compared to a proper double wishbone suspension.

The first and most obvious is that they do not have the same range of motion. A typical strut-type suspension has fewer links (i.e. no upper control arms) which limits articulation. Put more simply, a well engineered double wishbone setup is designed to increase negative camber as it compresses, which actually helps to maintain the contact patch on the inside wheels. Strut suspensions are not as good at this because their range of motion is more limited to the vertical plane.

The second shortcoming of struts is that the strut body is used as a semi-structural member in the suspension. That means the strut itself is actually bearing some of the weight of the car. That in turn causes more stress to be transferred to the chassis. What that means is that you either have a flexier chassis due to the increased stress transfer, or you need to make the chassis more rigid to handle it, which increases weight (without allowing the car to take full advantage of the benfits of having a stiffer chassis).

The third issue is more Honda-specific, yet no less important to me. It has to do with the packaging. While strut setups usually take up less space in the engine bay, they are taller. That results in a higher hood and cowl line. Personally, I like the cowl and hood to be as low as possible. It gives a greater sense of connection with the road, and IMO is a significant factor in how a car feels. One of the earliest things that attracted me to Hondas in the first place was the ultra-low cowl height, made possible by the double wishbone suspension. Therefore, I feel that the double wishbone suspension is the single most important feature of the old chassis. It is because of this marked change in feel that I don't even consider the RSX a proper Honda. If Honda was making cars like the RSX 12 years ago I never would have been attracted to their products in the first place.

 

I'm curious -- the cowl line of the RSX is still very low. How did they manage this? While a low cowl certainly helps with visibility, I've always felt that road feel and structural rigidity was far more important when it came to a sense of connection with the road. The RSX provides this along with a structural tightness the DC2 just can't match.

I was also wondering why, if MacPherson strut-type suspensions were vastly inferior to the point where they exhibited obvious deficiencies while under stress, they are used on so many cars which perform so well? (the WRX is a good example). Cost is one reason. What are the others?

The DC5 is only slightly heavier than the DC2. With equally spec'd Type-R "Integras", the DC5 has consistently been faster around a track than the DC2 (as per a number of Japanese tests). I'd argue that the MacPherson-type suspension, while technically inferior, is not the Achilles heel some people are making it out to be.

In my opinion, my 10-year-old E30 M3 still provided better road feel than either the DC2 Type-R or the DC5 Type-S (I've owned all three). On the drawing board the DC2-R should prove to be the best as far as balance, but in reality, that just isn't the case. There is so much more to suspension tuning than MacPherson strut vs double wishbone.

gi.


[Modified by Greg I, 2:30 PM 5/4/2002]

 

Interestingly, in the latest Car and Driver sport coupe comparison, all five cars tested have MacPherson strut front suspensions. The cars tested:

2002 Acura RSX Type-S
2003 Hyundai Tiburon GT V-6
2003 Misubishi Eclipse GTS
2002 Toyota Celica GT-S
2002 Volkswagon New Beetle Turbo S

If a double wishbone suspension were so advantageous, i would think at least one of these other manufacturers would have implented it here. My guess is that while a double wishbone front suspension may be easier to lower or modify due to its increased travel, it doesn't necessarily mean that it performs better than a MacPherson strut front suspension, both being in their stock configuration.

 

The RSX cowl is noticably higher than that of the DC2. I do not consider it "low" by any means. However, the driving position is higher as well in the RSX, and perhaps that gives the illusion of a lower cowl height.

I never said struts were vastly inferior, however there are indisputable technical shortcomings to the design and those are what I was illustrating. Perhaps they are not an achilles heel, but nevertheless it is a disappointment to see a technological step backward, which the struts definitely are.

Why do automakers use them? Probably because most people wouldn't bother to notice. Yes, there are very well-performing cars using strut suspension. Guess what. Every one of them would be even better with double wishbones. The WRX is an extremely fun car to drive. Does it feel like an Integra? No. Guess which one I prefer.

I don't see why you would think the DC2R would be more balanced than the E30 M3. The M3 has far better weight distribution as well as RWD. It doesn't surprise me in the least that that particular car would be the more rewarding drive, in spite of the suspension architecture.

And yes, you are right to say that there is more to suspension tuning than the basic architecture. That's why I think it's idiotic for people to defend the RSX's suspension by bring up the fact that 996s and M3s use struts. But that wasn't the question posted here. The question was about the shortcomings of strut suspension and why some Integra owners are disappointed in Honda's decision to use struts in the RSX.

 

Travel has nothing to do with struts vs. double wishbones. Either can be designed with any amount of travel required of a road car.

Double wishbone suspension is actually more difficult to lower properly. Why? Because of the more complex range of motion of a double wishbone suspension. This is why most lowered Hondas require camber adjustments.

 

because cars are getting cheaper, makers want more money and are only thinking of us as using these cars for every day driving. they don't care so much about performance, or we'd have the skyline, silva, and civic type R.

 

It's for cost savings and packaging reasons that many manufacturers uses MacPherson struts. MacPherson struts take up less space and allow more room for larger engine, additional electronics, safety equipment, better crash test results along with being less expensive to produce than a comparable double wishbone setup.

It all comes down to economics. It's cheaper for Honda to build them this way, so they're doing it.

 

Thanks for the info, Guys.

 

MacPhersons are not inherently worse or better than wishbones- they are different designs is all. The engine bay in the RSX is really cramped for space, so they were probably a design necessity. I don't think they're "bad" at all.
I believe that Porsche and BMW use Macphersons up front as well, so how bad can they be?

 

Here we go again with bmw and porsche arguement... the biggest thing that bmw and porsche has going for them is RWD setup. You can't compare FF RSX setup to RWD bwm, porsche setups. In those cars, front wheels is only directing the car and not required to put down the power as is needed in RSX or any other FF cars. This comparo just cannot be done...

 

FR = bmw
MR = porsche

my corrections.

 

 

This is the end of this arguement...No personal attacks please.

 

Porsches are rear-engined.

The MacPherson struts are simply not that big of a deal.

 

thats what the "MR" stands for...Mid Engine Rear Wheel Drive...yes the engine is in the rear, but them silly kids call it mid instead of rear...hence where the MR2 got its name from

 

"thats what the "MR" stands for...Mid Engine Rear Wheel Drive...yes the engine is in the rear, but them silly kids call it mid instead of rear...hence where the MR2 got its name from "

Not quite.

Incorrect. Porsche 911 is rear engined. The weight is entirely behind the rear axle.

Correct, the MR2 is mid-engined, and the name means "midship racer" -- that is not the typical meaning of MR in reference to mid-engine rear wheel drive.

Regarding my comment of the ITR coming across better than the E30 M3 on paper. It's a newer car, built on inherently better suspension technology (especially in the rear, where the E30 M3 falls in it's face if you're bench racing). When you then ADD the aspect of which wheels are driving the car, and the dynamic feel of different chassis, it's another story.

It is not idiotic to bring up the fact that other very well set-up cars use MacPherson struts. It's both a point of fact, and a point of reference.

gi.

 

thank you for correcting me, but isn't the porsche still considered to have a MR set up? not sure, just asking...

 

"thank you for correcting me, but isn't the porsche still considered to have a MR set up? not sure, just asking..."

Nope. It's "rear engine, rear drive". RR

Well, there are FR Porsches (944, 924, 928), and MR Porsches (914) as well.

gi.

 

thanx

 

Thanks for the defense Greg I. This argument has obviously been made before, with the drive wheels and the MacPhersons - sorry I'm not omnipotent and did not know that this had happened.
Point is well taken that the front wheels are doing a lot on a front-driver. My point is that the design of MacPhersons is not inherently bad, that's all.

BTW, the Boxster is another example of MR... And a 911 truly is RR, with the engine behind the rear axle.
Now, one could argue that the 911TT and Carrera 4 are also driving the front wheels, so the argument that MacPhersons with front driven wheels is kind of moot.

 

Yes, but not 100% of the torque is going to the front wheels in those porsches, however.

 

It is entirely inappropriate to compare high-dollar RWD European GTs with a FWD Honda as a defense for the RSX's struts.

"Gee, the 996 has struts and it handles just fine."

Those are the comparisons I am referring to, and they are completely invalid. You said it yourself: "There is more to suspension tuning than struts vs. double wishbones." You're absolutely right on that score. There is more to it than that. A FWD car like an Integra (or RSX) needs all the help it can get because it is handicapped from before the beginning by its layout. The struts are even more of a handicap. Argue all you like, the objective facts are that double wishbones are superior to struts, and FWD cars need every advantage possible in suspension architecture due to their disadvantageous layout. Period.

 

[QUOTE]It is entirely inappropriate to compare high-dollar RWD European GTs with a FWD Honda as a defense for the RSX's struts. [QUOTE]

Why is it inappropriate? If RSXs are going to race in the same class as European GTs (I won't even touch the "high-dollar" comment - that is inconsequential), such as BMW 3-series cars, I think it is VERY appropriate discussion. Right now Integra Type Rs run against 328s/330s in the Speed Channel Touring Car series. I would imagine that the RSX is close to being developed enough to join this group since the Integra (DC2) is no longer produced. So if (understood "IF", as I am assuming the RSX will show up) the RSX runs against these cars, it will need to be competitive with the MP struts.

 

Yes, it will need to be competetive, but will it? Like I said before, the FF layout is a huge handicap, which the double wishbone suspension in the old model helped negate. Can the RSX, with it's less optimal strut suspension, remain competetive? I doubt it.

Besides, the fact that ITRs ran well against 3-Series Bimmers in T2 doesn't mean it's in the same class. Indeed, it is absolutely amazing that it did, and I attribute that to the double wishbone suspension.

But it is inappropriate to compare what amounts to a FWD econo-hatch to a RWD GT. Why doesn't anybody point out a FWD, 4-cylinder, economy-car-based sport compact with strut suspension that handles as well as an ITR? That would be a valid comparison.