This topic has been bantered about on different websites here is some real info on what's currently out there. So what is "marketing hype" and what is real? Is one spring better than another? Which springs have brought home the wins? How about a :::::::::: "just show me" what you have done.......

regardless here are the basics............. as we know them now



I stopped by the engine shop today and broke out the gram scale and weighed a few things.................

Stock Spring 52.5g (obviously there are discrepancies between springs as the dr found they were 1 gram lighter)
stock retainer 11.8g
intake valve 44.5g
exhaust valve 38.3g
stock Keeper 1.8g!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!! oofa

(Cosworth and NS weights are from Dr. O himself)

Cosworth
Single spring weighs 49.5 g each (but is stock spring rate)

NS PAC Beehives with custom retainers
Spring weighs 48.8 g
Retainer weighs 5.9 g



Supertech RMW kit
dual spring 44.5g about 10% lighter than NS beehives
titanium retainer 5.7g still lighter than NS
1.8mm oversized intake valve 45.3g
2.3mm oversized exhaust valve 40.6g
Keeper .7g!!!!!!!!!!!!!!!!!!!!258% lighter than what's used on others setups
considering our valves are much bigger and yet still light I'm thrilled at the comparisons

considering LIGHTER is ALWAYS better per Matt (dr.obnx) I'd say from the outlook here NOT much is going to be gained from going to beehive's unless SUPERTECH'S are that much better than the PACs

but...........like I said, I will be happy to test the supertech beehives when they come out for a more informed Mini community as using V-8s for your comparisons mean very little when compared to overhead cam roller rocker 4 bangers.....

jan

Here at RMW we test all of our products on the track and on the dyno to see how they work. It's the only true way to test the product. What works on other cars doesn't necessarily work on ours. Using this logic is flawed in my opinion and we won't test our products this way. I should have some Supertech beehives in a few weeks to test. Should be fun. Let's hope they get here on time!

 

Very enlightening info Jan, thanks for taking the time to test!!

 

NOT ON POINT -
258% lighter would be negative weight.
Just a pet peve of mine right now. If something is measured related to another item is can not be more than 100% less.
Just saying, it should be 61% lighter, or 39% of the others weight.

 

Jan, I'll be very interested in hearing about dyno results on the Mini.

In addition to weight reduction, the beehive shape and the ovoid wire used is also claimed (by Nascar builders) to reduce valvetrain harmonics when compared to double-springs with interference damping between.

In the Nov2010 Hotrod p88, there is a dyno comparison of beehive vs. double (with no other changes) that shows small gains for the beehives at only 2500RPM and big gains over 6500RPM. There was also a detailed article comparing springs designs on dyno and spintron a year ago that is available online:
http://www.corvettefever.com/techart...nfo/index.html

Obviously, neither example is from a Mini.

Food for thought,
- Jim

 

RMW BEEHIVE SPRINGS

Ti Retainers 5.4g
Keepers 1.2g total per valve
Spring 44.2g