F451

Hey guys,

Does anyone know the exact difference between the sunroof and sunroof delete 928's as far as headroom goes? I've heard a lot of numbers thrown around, but I'd really love to hear from someone that has measured it exactly.

Most accurate measurement would be same model year cars, side by side. Perhaps measure from same point of roof, down to same point of seat (seat at lowest setting, measure to lowest point of seat bottom cushion), or measure to the floor?

In any case, I'd really love to see some actual numbers.

Thanks,

Ed

Imo000

Most headroom is in a manual seat, non sunroof 928 and the oppsite, power seats sunroof. However, I woudl be interested too to see the exact numbers. My guess is 1.5" with poweer seats and no sunroof and over 2" with manual seat and no sunroof.

Also some seats are slightly thicker than others. Then there are the leather seats with cloth inserts that feel a little thicker than full leather.

F451

And the reason I ask is I'm trying to get as much headroom as I can. I'd like to track my car, but there is no way I'll be able to get a helmet on the way it is now. And even if I get more headroom and can squeeze a helmet on, I believe there are minimum helmet clearance rules for most track events.

In my '88 S4 (was the same in my '85) with sunroof, at 6'6", I have about 1/2" headroom clearance. My hair brushes the roof. Seat is bottomed out in the back, up higher in the front. Reclined way back. I've played with the adjustments to no end, and I have it maxed out for clearance.

I just test installed a Sparco Sprint fixed back seat (thanks Chuck, I stll need to make my United Way donation - haven't forgot!) with sliders, and that got me a lot more room. I now have about 2" of clearance, and I can sit upright. Its way more comfortable. I can also reach the controls much more easily since I'm sitting way more upright. This is the right direction.

But, with a helmet one, I have between 1/2 - 1" clearance. Still not enough for track duty with the minimum helmet clearance req's.

With a fixed back seat with a fixed bracket (no sliders), I think I can get about another inch.

That would get me to about 3" clearance without a helmet, about 1.5 - 2" with a helmet. I'm not sure that will be enough clearance for track duty.

Sooo, if I knew exactly how much additional room I would get with a sunroof delete 928, I may consider selling my S4 and trying to find a sunroof delete 928.

Any input is greatly appreciated. Thanks.

Imo000

Shave your head, loose the underwear and voila....you are there!
On a serious note, what is the required clearance? Over 2" seems a little much.

F451

Good points Imo.

Perhaps measuring same model year 928's from the same point of the roof, down to the same spot on the floor?

This would eliminate all of the differing seat variables.

Perhaps put the seats in the same position (seat as far back from the pedals as possible?), then flip the seat back up (like when people are getting in and out of the back seats). Then measure on a vertical line from just behind the seat straight up to the roof liner.

Might also be a good idea to remove the carpeting on the floor (my S4 has two layers of carpeting in the back = 1").

In other words, remove as many variables as possible.

F451

Duuuude. I already ditched the mohawk for this car. What more do you want of me? LOL!

I'm not sure what the minimum helmet clearance req's are, I'm sure they differ. But I saw in the SCCA rule book mention of:

I'm not sure if this is 5 inches, or 5 cm? Seems crazy if its 5 inches.

I'll be starting another thread on minimum helmet clearance for tracking (DE's, track days, autox, racing). Ok, that one is here: https://rennlist.com/forums/928-forum/386724-de-s-autox-track-days-racing-minimum-helmet-clearance.html

PorKen

The no-sunroof '80, which I had briefly, gave me about 2" clearance with a power seat!

In my '81, with manual sport seats my head touches the headliner. Both '86s, which have ¾" lower seat rails (starts in '83?) my noggin hits the sunroof on bumps.

With a no-sunroof, manual or race seats, and 83(?) up, you could have 2-3" extra headroom.

Garth S

Also at 6' 6", every sunroof equiped 928 I've driven requires some torso contortion and neck twisting to avoid roof contact - no way with a helmet!
On the other hand, my 16v and the ex - S4, both sunroof deletes, offer perfect driving position. Still, with a helmet in these cars, the seatback has to be reclined a little further.
Sorry - no measurements ever taken.

jon928se

Definitive answer (ignoring seat sag)

70mm.

My head is 70mm clear of the headliner in the 88 SE (No sunroof)

It touches the headliner in the 90GT.

Only differences between the two cars, other than GT sunroof, the SE sports seats have 30,000 miles (of my not desperatley heavy ***) more on them than the GT. (Oh and not realy relevant, at the time of measuring (about 5 minutes ago) the SE was on it's wheels and and the GT was on axle stands minus X member, steering rack, front suspension and some oil)

So there you have it.

F451

Very cool Jon.

70 millimeters = 2.75590551 inches.

I think that last .00000051" may just do it for me! Ha ha...

No really, 2.75" is right inline with what people have been telling me.

That would be more then enough head room when combined with a racing seat.

Hmmm...

Ok, thanks for all the input guys!