Pagoda SL Group

W113 Pagoda SL Group => Research & Development => Topic started by: mmizesko on October 02, 2023, 15:41:16

Title: Damn softtop buffetting at highway speed
Post by: mmizesko on October 02, 2023, 15:41:16
Has anyone experimented with some sort of air deflector that might fit between the windshield and the front of the soft top?  I am still deaf after driving the 8 hours back to Columbus from PagodaFest.  Love that South Chicago Traffic.
Title: Re: Damn softtop buffetting at highway speed
Post by: rwmastel on October 02, 2023, 16:23:36
You mean like this, but attached to the header of the windshield?
Title: Re: Damn softtop buffetting at highway speed
Post by: mmizesko on October 02, 2023, 17:05:14
yes, but probably more rigid.  I'll check with my aeronautical engineer experts.

Mike
Title: Re: Damn softtop buffetting at highway speed
Post by: John Betsch - "SADIE" on October 02, 2023, 17:55:03
I would think the more important question is why your top does this?  Not address the symptom but the cause?  Of course I didn't have to listen to it for 8 hours
Title: Re: Damn softtop buffetting at highway speed
Post by: thelews on October 02, 2023, 18:52:54
Ear plugs
Title: Re: Damn softtop buffetting at highway speed
Post by: dirkbalter on October 02, 2023, 18:57:37
Mike,
I am in the process of installing a soft top on my car. I cant speak from experience (yet), but it was pointed out to me from some of my buddies at the “pagodas and beer” meeting, that a wind noise often is due to the front of the soft top not properly wrapped around the front bow. My understanding is that the bead on the top needs to touch or better, should not have any gap to the upper window frame. Looking at some of the tops on the cars, even professional installations don’t always get it right.       
Title: Re: Damn softtop buffetting at highway speed
Post by: BobH on October 02, 2023, 19:50:52
If the tensioning straps are worn, the hood may not be as taut as it should be, and the hood will flap more than it should, i've just changed the canvas top on my Landrover and the new taut canvas has reduced the wind noise a great deal

MrFatboy was selling new straps a few years ago, but i'm not sure if they can be changed on an existing top?

https://www.sl113.org/forums/index.php?topic=29864.msg218905#msg218905
Title: Re: Damn softtop buffetting at highway speed
Post by: mmizesko on October 02, 2023, 20:53:58
Thanks guys.

The Lews gave me his tip on Saturday.  I'll try to re-adjust first, and look at the front and straps, before I hire a mechanical engineer.  I should be able to hear again tomorrow some time.

Mike
Title: Re: Damn softtop buffetting at highway speed
Post by: Cees Klumper on October 03, 2023, 04:41:13
My top is very quiet even at highway speeds, no windnoise at all much less any bufetting. No gap also due to the rubber seal between the windshield surround and the top (also important to keep any rainwater out?).
Title: Re: Damn softtop buffetting at highway speed
Post by: Peter on October 03, 2023, 07:44:07
Dear Cees,
could you take some pictures to see how it fits,
thanks Peter
Title: Re: Damn softtop buffetting at highway speed
Post by: Cees Klumper on October 04, 2023, 07:28:18
I tried to take some photos just now but had a difficult time. Best photo below shows the seal, that I replaced with new some 20 years ago and is still very newish, flexible etc, that provides the seal between the top of the windshield frame and the bottom of the soft top frame. It keeps all airflow out, airtight seal. Any remaining windnoise, which I don't notice even at 80 MPH, would be whatever is generated by the shape of the design:

Title: Re: Damn softtop buffetting at highway speed
Post by: Peter van Es on October 04, 2023, 07:58:38
I drove to the Nuremburg event and back top down, even on the motorway. Much more silent than top-up.
Title: Re: Damn softtop buffetting at highway speed
Post by: rwmastel on October 04, 2023, 15:06:37
Mike,

Have you ridden in a Pagoda with a wind deflector installed behind the seats?  I have not, but they're said to do wonderful things regarding reduced hair knotting for your VIP (very important passenger).  Then you don't have to worry about the soft top buffeting.
Title: Re: Damn softtop buffetting at highway speed
Post by: mdsalemi on October 05, 2023, 12:09:30
I just drove my Pagoda for four solid days at 65-75 MPH (3500 - 4000 rpm) through five states to and from PagodaFest, top-up. I ran into periodic bouts of rain, some of it very heavy, on the way up to PagodaFest, so top up was required. The fifth day was on the driving tour, about 70 miles top-down, with the wind screen. My car has always been quieter with the top up than with the top down.

No matter how you describe this, it was in a word, deafening. Yes, with the top down and the windscreen up it’s far more pleasant than without but it’s still very loud. My top does not flutter or buffet much at highway speed, but that doesn’t stop the deafening sound from outside or the roar of an engine turning at over 3500 RPM.

I have had over 20 years experience in highway driving with this car, and I know to wear earplugs. For this trip however, I purchased an inexpensive pair of earbuds with active noise cancellation. What an amazing difference when you turn the ANC off and on. Unfortunately, the ANC sucks the battery down pretty quickly and I could only get 2 to 6 hours of use out of these earbuds when they advertised 140. But it was pretty obvious how much noise was getting to the ear buds to be canceled--just drive at 70 and turn ANC off and on. That tells you how much ambient noise you have around you.

When the exhaust fell and started scraping the ground that noise got through the ANC. I heard it and felt it through vibration as well.

These are not quiet cars. They never were and never will be. They are also quite hot driving. But we love them anyway.