New Ohlins DFV Road & Track Coilovers (HOS MI21)?
02-19-2019, 05:42 AM
#101
Is it difficult to understand what they did? Yes it is.
A quote:
"...we only had 5mm stroke left before entering the bump rubber. In other words, hitting the bump rubber will happen a lot at the track making the car loose grip in the rear. Main reason was not that a too stiff rear spring was used."
Ok, so the limited rear compression stroke causing oversteer makes total sense. But the statement above, that somehow a stiff rear spring caused limited compression travel defies logic.
In fact, the way some vendors like SBG addressed the limited travel was to use a STIFFER rear spring. So Ohlins goes to fix it themselves, and their solution (in part) is a SOFTER rear spring? This is what is causing so much confusion.
If they had simply said they fixed it by shorter shock body and the other things they did, and still had room left over to allow a softer rear spring, which helped balance, or whatever it really did, things would probably have gone much differently. But by pinning the cause of limited rear travel on something tbat doesn't make any sense, caused people to question everything they did.
I think the lesson is technical writing is a special skill. Often the technical people that understand things the best are the worst people to use to try and communicate it to the rest of the world. Yet technical writers that emphasise the literary aspect of their trade often don't fully understand the technical subject they are documenting.
So mistakes like this happen. They wrte something that is 100% wrong, but the real tech people that review things don't catch it because they are not good at language skills.
Rare is that person that can bridge those gaps and sufficiently understand the technical details, posses the language skills to communicate them accurately, and have a knack for explaining things that people can really understand.
I blame this whole thing on bad technical writing...
A quote:
"...we only had 5mm stroke left before entering the bump rubber. In other words, hitting the bump rubber will happen a lot at the track making the car loose grip in the rear. Main reason was not that a too stiff rear spring was used."
Ok, so the limited rear compression stroke causing oversteer makes total sense. But the statement above, that somehow a stiff rear spring caused limited compression travel defies logic.
In fact, the way some vendors like SBG addressed the limited travel was to use a STIFFER rear spring. So Ohlins goes to fix it themselves, and their solution (in part) is a SOFTER rear spring? This is what is causing so much confusion.
If they had simply said they fixed it by shorter shock body and the other things they did, and still had room left over to allow a softer rear spring, which helped balance, or whatever it really did, things would probably have gone much differently. But by pinning the cause of limited rear travel on something tbat doesn't make any sense, caused people to question everything they did.
I think the lesson is technical writing is a special skill. Often the technical people that understand things the best are the worst people to use to try and communicate it to the rest of the world. Yet technical writers that emphasise the literary aspect of their trade often don't fully understand the technical subject they are documenting.
So mistakes like this happen. They wrte something that is 100% wrong, but the real tech people that review things don't catch it because they are not good at language skills.
Rare is that person that can bridge those gaps and sufficiently understand the technical details, posses the language skills to communicate them accurately, and have a knack for explaining things that people can really understand.
I blame this whole thing on bad technical writing...
The following users liked this post:
Chris Thomas (07-21-2019)
02-19-2019, 06:17 AM
#102
Is it difficult to understand what they did? Yes it is.
A quote:
"...we only had 5mm stroke left before entering the bump rubber. In other words, hitting the bump rubber will happen a lot at the track making the car loose grip in the rear. Main reason was not that a too stiff rear spring was used."
Ok, so the limited rear compression stroke causing oversteer makes total sense. But the statement above, that somehow a stiff rear spring caused limited compression travel defies logic.
In fact, the way some vendors like SBG addressed the limited travel was to use a STIFFER rear spring. So Ohlins goes to fix it themselves, and their solution (in part) is a SOFTER rear spring? This is what is causing so much confusion.
If they had simply said they fixed it by shorter shock body and the other things they did, and still had room left over to allow a softer rear spring, which helped balance, or whatever it really did, things would probably have gone much differently. But by pinning the cause of limited rear travel on something tbat doesn't make any sense, caused people to question everything they did.
I think the lesson is technical writing is a special skill. Often the technical people that understand things the best are the worst people to use to try and communicate it to the rest of the world. Yet technical writers that emphasise the literary aspect of their trade often don't fully understand the technical subject they are documenting.
So mistakes like this happen. They wrte something that is 100% wrong, but the real tech people that review things don't catch it because they are not good at language skills.
Rare is that person that can bridge those gaps and sufficiently understand the technical details, posses the language skills to communicate them accurately, and have a knack for explaining things that people can really understand.
I blame this whole thing on bad technical writing...
A quote:
"...we only had 5mm stroke left before entering the bump rubber. In other words, hitting the bump rubber will happen a lot at the track making the car loose grip in the rear. Main reason was not that a too stiff rear spring was used."
Ok, so the limited rear compression stroke causing oversteer makes total sense. But the statement above, that somehow a stiff rear spring caused limited compression travel defies logic.
In fact, the way some vendors like SBG addressed the limited travel was to use a STIFFER rear spring. So Ohlins goes to fix it themselves, and their solution (in part) is a SOFTER rear spring? This is what is causing so much confusion.
If they had simply said they fixed it by shorter shock body and the other things they did, and still had room left over to allow a softer rear spring, which helped balance, or whatever it really did, things would probably have gone much differently. But by pinning the cause of limited rear travel on something tbat doesn't make any sense, caused people to question everything they did.
I think the lesson is technical writing is a special skill. Often the technical people that understand things the best are the worst people to use to try and communicate it to the rest of the world. Yet technical writers that emphasise the literary aspect of their trade often don't fully understand the technical subject they are documenting.
So mistakes like this happen. They wrte something that is 100% wrong, but the real tech people that review things don't catch it because they are not good at language skills.
Rare is that person that can bridge those gaps and sufficiently understand the technical details, posses the language skills to communicate them accurately, and have a knack for explaining things that people can really understand.
I blame this whole thing on bad technical writing...
The problem with this is we don't know the setup of the test vehicle(s?) they used to make these adjustments. On the majority of S2K track cars with a square setup, big front bar, rear wing - increasing the spring rate stagger may not make sense. The car they used may have also had a larger rear sway bar and no aero - making the driver feel like he needed more rear grip. I'm not saying this is exactly what happened, but knowing how they baselined what they did would help shed a lot of light on the situation.
Also - we're still hearing two completely different things from a lot of people, many well-respected. Ohlins says they've made changes and increased stroke, SBG says only valving and springs have changed but stroke is the same.
I'm looking to start doing TT in the middle of this year and will prefer to move from my KW V3's to something without reservoirs to gain points back - Ohlins seemed like a no-brainer but with everything up in the air I may start researching other options.
02-19-2019, 07:53 AM
#103
So amazed that nobody has even tried them on the track!
the snow started melting here a few days ago, can’t wait for spring to arrive and take the car to the track!
the snow started melting here a few days ago, can’t wait for spring to arrive and take the car to the track!
Last edited by Berni; 02-19-2019 at 08:40 AM. Reason: Got tired of trying to explain to people that don’t want to understand.
02-19-2019, 09:54 AM
#104
But the only changes Öhlins did to increase stroke was to ad more spring preload, one whole millimeter more from the previous revised 9mm.
What makes it confusing is that they seem to compare it to the old and first spec of 1-2mm preload.
Besides that I think Car Analogy sums it up really good
02-19-2019, 10:52 AM
#105
I'm pretty sure they both are correct.
But the only changes Öhlins did to increase stroke was to ad more spring preload, one whole millimeter more from the previous revised 9mm.
What makes it confusing is that they seem to compare it to the old and first spec of 1-2mm preload.
Besides that I think Car Analogy sums it up really good
But the only changes Öhlins did to increase stroke was to ad more spring preload, one whole millimeter more from the previous revised 9mm.
What makes it confusing is that they seem to compare it to the old and first spec of 1-2mm preload.
Besides that I think Car Analogy sums it up really good
From Ohlins, posted earlier:
To avoid hitting the bump rubber due to the short compression stroke from ride height, we increased the spring preload (raising the car) but decreased the length of the damper (lowering the car again) by adjusting the length adjuster cup keeping the same ride height as before. This way we were able to gain 20mm more compression stroke without changing any hardware on the shock absorber.
The result is that from ride height we now have approximately 50mm of compression stroke and 50mm of rebound stroke.
The result is that from ride height we now have approximately 50mm of compression stroke and 50mm of rebound stroke.
So I guess SBG could say TOTAL stroke is the same but compression stroke is what we're focusing on and SBG says it's the same as the old kit and Ohlins says it's different
02-19-2019, 11:51 AM
#107
They can't both be correct - either it has more compression stroke or it doesn't.
From Ohlins, posted earlier:
So my understanding is previously you only had roughly 30-35mm compression stroke (~5mm to hit the bump rubber) and ~70mm rebound stroke at the target ride height, now it should be 50mm compression and rebound since preload has been added but lower cup height reduced (***If my understanding of this is wrong please let me know and feel free to explain***)
So I guess SBG could say TOTAL stroke is the same but compression stroke is what we're focusing on and SBG says it's the same as the old kit and Ohlins says it's different
From Ohlins, posted earlier:
So my understanding is previously you only had roughly 30-35mm compression stroke (~5mm to hit the bump rubber) and ~70mm rebound stroke at the target ride height, now it should be 50mm compression and rebound since preload has been added but lower cup height reduced (***If my understanding of this is wrong please let me know and feel free to explain***)
So I guess SBG could say TOTAL stroke is the same but compression stroke is what we're focusing on and SBG says it's the same as the old kit and Ohlins says it's different
Since front stroke is changed only by adding a spacer that ads up as well.
02-19-2019, 12:01 PM
#108
Do you mind explaining why? The original issue with the first kit was that there wasn't enough compression stroke so users were easily hitting the bumpstops (bad).
02-19-2019, 12:37 PM
#110
My interpretation is that SBG is talking about TOTAL stroke (which is what really matters).