Strut question for 74 super
 

Hi guy's I am new to this site and just about to start my new project and had a few questions about strut choices for my 74 super .
I am looking at toplines maxx and maxx xtreme struts and wanted to know if anybody has experience with the xtreme version they offer . I talked with them about this choice over the regular maxx struts and they recommended using kyb gr2 inserts which will give a nice firm ride and work well with this strut , the big drawback as I understand is the spring rate is a little stiffer then the regular maxx strut { 80 lbs. as opposed to 65 lbs } and the adjuster set up can collect road grime and make it a little tough for adjustment after time. This car will not be a daily driver and probably will not see much if any bad weather .
Any other affordable recommendations would be considered
Thanks

im in the same boat as you... I am contemplating going with the maxx extreme, i think since yours wont be a daily driver you will not mind the stiffer spring rate as you will get better performance, what i am consider doing is making a neoprene (or similar material) sleeve to go over the threaded part... I have a couple ideas i am pretty sure that will work, if they do and you want i will pm you with what i end up doing

I assume that the Maxx Extreme struts have threaded platform tubes plus 2 1/4" springs. the adjustable platform type are desireable on two fronts - 1) adjustable ride height and 2) large selection of alternative spring rates. I am surprised that the Maxx struts have 65lb/in springs as the standard springs are 80lb/in and the general concensus (here at least) is that the stiffness needs increasing for fast road and track use. I reckon on 100lb/in springs for fast road use and others use higher rates for more competition bias. As regards the Maxx Extreme struts for daily use relating to their maintenance it depends on your own maintenance regime. I would have no trouble keeping them working even though I would do around 10,000mls/yr. If however you require a fit and forget system then get your spring rate and length sorted first and use a fixed platform strut.

Clive

Thanks for the reply's , I think I am going to go with the maxx xtreme's . I can't see it being a big deal to keeping the strut body clean and I like the idea of adjustability . Like I said before this car will rarely see any bad weather and the firmer ride won't bother me as this is not my daily driver .


John

Hey John,

I have a set of Koni Coilovers on my Golf. I cover the threaded bodies with grease and the threads stay protected from the road grime. A liitle brake clean to wash the threads, and the rings move easily up/down when needed.

Pete

John!

Good to see you aboard! I know you're super will be super duper;)
I can't offer any strut advice, when it comes to cars I don't touch the fat chicks;) ( no comments from the peanut gallery on how my '70 is a fatty!:D)

Cheers,

Alex Barrie

Hi, I have the maxx struts and have emailed Topline to get the definitive spring rate for these. I thought they were around 65-70lbs.

In autocross, what will be the effect of being undersprung in the front? Since the maxx strut is adjustable I could swap springs if needed. Car will see 90% street.

The car rides nice and smooth on the street but haven't had it on the course yet to really push it. So far it seems like it might understeer a bit but I'll deal with that when I get on the track.

Mike

Just heard from Jon at Topline, Maxx springs are 71.5 lbs/inch

They tested the stock springs at 60-65 lbs/inch.

One other note is in the 3-400 miles I've had my struts installed the ride height has sagged over an inch, I'm now at the top spring perch position, could probably use another 1/2" height since our roads are so brutal.

I found that with the maxx strut springs at 71# I spent a lot of time on the bumpstops, especially with hard corners or a passenger. So far with the 200# springs in front I think it's a perfect mix between street and track.

I'd like some stiffer ones for mine too, stock maxx springs arent quite firm enough for me

i also had probs with it sitting too low, i had some extra grooves machined in above the stock ones just for that extra 1/2"

This weekend I did a 600km round trip and did some camping with mine, with my wife and I in the car, and full of our camping gear I had about 1" of travel in the front, with the struts in the highest position!

For some reason over at superbeetlesonly forum, there is talk that anything over 80lbs/inch is way too harsh for the street, and 100lbs is downright dangerous. Then again I also have a big radiator up front.

Now I'm faced with what springs to go with, and then if going higher spring rate in the front should the rear be increased also?

Buggin_74, It looks like we're in the same boat, I'd be happy with about another 1/2" of ride height. I was just surprised how much these springs settled since new.

I did some coil spring calcs for a Super using Humbles corner weights that showed that the front struts should be between 73lb/in and 113lb/in for a fast road car. These are based on coil frequencies of 80-100 hz that are 'industry standard' for fast road. My very crude assessment of some standard old springs put them in the 80lb/in range not the 70lb/in suggested but it may be that these are European rates that are typically higher than American rates (did VW have a softer suspension for the US market?)

http://www.germanlook.net/forums/sho...t=10384&page=2

If you have coilovers with 2 1/4" springs you could get progressive rate units wound or a dual rate with a version of stiff helper springs at say 75lb/in plus something over 100lb/in. The final rates of course will be determined by the actual corner weights especially for a Scooby powered bug.

Clive

That's a great thread, I'd forgetten about it. It should almost be linked in the suspension sticky.

I think I might just go with some 100lb springs for the front, see how it works, and then upgrade to 944 TB when I actually find some. Just hopefully with 100lb up front and stock out back it doesn't do anything weird.

Humble how do the 200lbs/inch ride on the street? There are a bunch of sources telling me that 100lbs/inch would be about right for my car seeing mostly street and some track but you have a lighter car with double the spring rate. Could this be due to a different rating system? I'll probably go with the QA1's as you have but I don't want to order the 100lbs/inch QA1's and have them too soft.

Mike

Warning, I'm just learning this stuff!

I came across this page below:

http://farnorthracing.com/autocross_secrets5.html

By 80-100Hz did you perhaps mean 0.8 - 1.0 Hz? as suggested by this page or is there something I'm missing?

Mike

Hi Mike, there is either an error in the text or they have automatically factored in a different constant. The equation that I use is:
WR{wheel rate} = (SF{spring frequency}/187.8)^2 x SW{sprung weight}. You can check this out on the Eibach Spring site for convenience:
http://performance-suspension.eibach...sion_worksheet as an example - just rearrange the equation or alternatively plug in the figures. You will see that the Cycles Per Minute (or Hz) are 80+. Remember on the front Macpherson struts the spring rate = the wheel rate for all intents and purposes and I have not deducted the unsprung weight from the corner weight as this is negligible.

If the standard spring rate on the front is 70-80lb/in then conventional wisdom suggests a 30% increase in rate for fast road that comes out to 91-104lb/in so that the 100lb/in is about right but the final value very much depends on your corner weight with all the extras you are carrying. On the rear where you suggest retaining the standard torsion bar the spring frequency is 95CPM on Humble's corner weights that will be too close to the front CPM of around 93CPM - that will induce uncomfortable pitching for and aft as the two frequencies are too alike, there needs to be at least a 10% difference. Why not add some coilovers to the rear with some light springs to increase the wheel rate?. The damper top mount will have some load capacity for light springing and if you get stiffer springs you could always add a 5 bar KC brace.

Clive