Race Car Tech Discuss anything related to road racing and auto X.

Hardtop vs. sunroof FD for track

Old 03-11-12, 03:04 PM
  #1  
They see me derpin'
Thread Starter
 
Join Date: Dec 2011
Location: Seattle, WA
Posts: 39
Likes: 0
Received 0 Likes on 0 Posts
Hardtop vs. sunroof FD for track

Hey, so first of all I did use the search function (I searched "titles only" with the keywords "slicktop," "hardtop," and "hard top.") However, I am still not 100% sure what the weight difference is between a slicktop FD and a FD with a sunroof. Also, is the difference in rigidity remarkable? Would someone primarily interested in road racing/auto X be better off with a slicktop or is the difference in rigidity/weight negligible?

I ask because I know there can sometimes be a big difference between slicktops and other types of roofs - for example, the 300ZX slicktop is 300lbs lighter than the t-top model and noticeably more rigid.

Thanks.
sittinSideways is offline  
Old 03-11-12, 04:17 PM
  #2  
Armchair engineer
iTrader: (2)
 
j9fd3s's Avatar
 
Join Date: Mar 2001
Location: http://www.k2rd.com
Posts: 24,603
Likes: 0
Received 123 Likes on 112 Posts
i've never heard the term slicktop..

anyways the weight difference is about 10lbs, its going to vary a teeny bit if its a glass roof, or a metal one.

structurally the FD is very solid, sunroof or not isn't a big deal. Mazda actually has an sae paper on the body shell.
j9fd3s is offline  
Old 03-11-12, 06:31 PM
  #3  
Doing the Ricky Bobby
5 Year Member
iTrader: (1)
 
Join Date: Jan 2008
Location: Dallas, Texas
Posts: 137
Likes: 0
Received 0 Likes on 0 Posts
The difference is so negligible that it not worth making a decision based on it. I personally have an r1 which doesn't have a sunroof which is nice to have the extra head room if you are tall but if I could choose I would have preferred having the sunroof. I will be doing some track days after I re-do the suspension on the car and built the car with that in mind (a half bridge t0r will have a great track power-band). If you don't have A/C it is a big plus to have a sunroof as the car got really hot this last summer when it didn't have functioning air conditioning...
rcracer_tx is offline  
Old 03-11-12, 06:41 PM
  #4  
Lives on the Forum
iTrader: (8)
 
ptrhahn's Avatar
 
Join Date: Feb 2002
Location: Arlington, VA
Posts: 8,492
Received 20 Likes on 19 Posts
Structurally, there's no difference at all. The weight is somewhere around 15-20 lbs, but of course it's at the very top of the car. Unless you're 6'8", headroom won't likely be an issue once you've mounted race seats.
ptrhahn is offline  
Old 03-11-12, 07:25 PM
  #5  
They see me derpin'
Thread Starter
 
Join Date: Dec 2011
Location: Seattle, WA
Posts: 39
Likes: 0
Received 0 Likes on 0 Posts
Excellent, thanks for the responses guys.

EDIT: found that SAE paper you were referring to: http://papers.sae.org/920244/
Anyone happen to have a copy or know where I could acquire it for free?

Last edited by sittinSideways; 03-11-12 at 07:49 PM.
sittinSideways is offline  
Old 03-12-12, 05:37 PM
  #6  
Searching for 10th's
iTrader: (11)
 
jkstill's Avatar
 
Join Date: May 2002
Location: Portland OR
Posts: 2,192
Received 4 Likes on 3 Posts
Originally Posted by ptrhahn View Post
Structurally, there's no difference at all. The weight is somewhere around 15-20 lbs, but of course it's at the very top of the car. Unless you're 6'8", headroom won't likely be an issue once you've mounted race seats.
It is not just your height and seats, but the length or your trunk (yours, not the cars) - basically your height minus inseam.

I am 5' 10.5" tall.

My FD has Corbeau race seats on sliders. The back feet of the seats were removed for better clearance.

With my sunroof FD I will hit my head on the roof sometimes.

Going to non-adjustable seat mounts will provide more clearance.

The only reason I have sliding mounts is seat adjustability for co-drivers.
jkstill is offline  
Old 03-18-12, 06:02 PM
  #7  
Senior Member
10 Year Member
iTrader: (3)
 
Join Date: Sep 2004
Location: CA
Posts: 258
Likes: 0
Received 0 Likes on 0 Posts
I would have chosen a non-sunroof if I knew then what I know now... Bot only because of the extra headroom. I'm 5-11, and a helmet with stock seats does not fit very well - I have to recline the seat a lot.
HadaVette is offline  
Old 03-19-12, 04:01 PM
  #8  
trying to build a racecar
 
Travis R's Avatar
 
Join Date: Sep 2002
Location: Austin, Tx.
Posts: 579
Received 1 Like on 1 Post
I've only driven 1 FD, but it had a sunroof, and I had a helmet on, and it was very annoying how far back I had to recline the seat. I'm 6'2"
So if I was looking for a track FD...
Travis R is offline  
Old 03-20-12, 03:54 PM
  #9  
Let's get silly...
iTrader: (7)
 
RockLobster's Avatar
 
Join Date: May 2004
Location: Rosemount, MN
Posts: 1,703
Likes: 0
Received 3 Likes on 3 Posts
6'4" tall and i dont fit in any FD with a helmet on period. Oddly enough it is one of the reasons I own FCs...

But there is about a 1.5" difference in headroom between sunroof cars and non-sunroof cars in stock form...both FC and FD.
RockLobster is offline  
Old 03-20-12, 09:07 PM
  #10  
Lives on the Forum
iTrader: (8)
 
ptrhahn's Avatar
 
Join Date: Feb 2002
Location: Arlington, VA
Posts: 8,492
Received 20 Likes on 19 Posts
You guys need fixed mount race seats, where the butt of the seat is hitting the floor.
ptrhahn is offline  
Old 03-20-12, 10:06 PM
  #11  
Full Member
5 Year Member
 
RotaryRX-007's Avatar
 
Join Date: Apr 2008
Location: Melbourne Beach, FL
Posts: 169
Likes: 0
Received 0 Likes on 0 Posts
+1 for *** of seat on the floor pan.

Non sunroof is the preferred for track duty for the prior reasons listed. But on the other hand, sunroof cars tend to be a little cheaper to buy. There's carbon replacement panels (i think one of the vendors offer it) for the sunroof and you can just gut the assembly to shave the weight. Since the rigidity between the two is kinda negligible, whichever car you get the best deal on, go for it.
RotaryRX-007 is offline  
Old 03-21-12, 09:54 AM
  #12  
Let's get silly...
iTrader: (7)
 
RockLobster's Avatar
 
Join Date: May 2004
Location: Rosemount, MN
Posts: 1,703
Likes: 0
Received 3 Likes on 3 Posts
Makes no difference in my case. Too big for FDs...

Although a buddy of mine is an inch taller and he makes it work because he is all legs...
RockLobster is offline  
Old 03-21-12, 06:05 PM
  #13  
Fast + Reliable = $$$$$
iTrader: (18)
 
PandazRx-7's Avatar
 
Join Date: Nov 2003
Location: SoCal
Posts: 1,221
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by RotaryRX-007 View Post
+1 for *** of seat on the floor pan.

Non sunroof is the preferred for track duty for the prior reasons listed. But on the other hand, sunroof cars tend to be a little cheaper to buy. There's carbon replacement panels (i think one of the vendors offer it) for the sunroof and you can just gut the assembly to shave the weight. Since the rigidity between the two is kinda negligible, whichever car you get the best deal on, go for it.

That's what I did...building a new track car with sunroof removed (probably 20lbs+) and plugged it a carbon fiber plug which weighed in at a hair over 3lbs. Cage hugs the roof so tight that there is no way to remove the nuts for the panel now. Also had the lowest possible fixed mount seat rails made so I should be good to go with head room. I'm about 5'11".
PandazRx-7 is offline  
Old 04-13-12, 04:27 PM
  #14  
Junior Member
 
Join Date: Apr 2012
Location: Trenton NJ
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
good info I'm 5'10 but have a large torso I'm gonna have to check this with a helmet before I buy a car
initial_r90 is offline  
Old 04-23-12, 10:44 PM
  #15  
There goes a prius!
5 Year Member
iTrader: (51)
 
FD3S4Life's Avatar
 
Join Date: May 2007
Location: Gardena, CA.
Posts: 664
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by PandazRx-7 View Post
That's what I did...building a new track car with sunroof removed (probably 20lbs+) and plugged it a carbon fiber plug which weighed in at a hair over 3lbs. Cage hugs the roof so tight that there is no way to remove the nuts for the panel now. Also had the lowest possible fixed mount seat rails made so I should be good to go with head room. I'm about 5'11".
Which vendor? im looking for a carbon sunroof plug right now too.
FD3S4Life is offline  

Thread Tools
Search this Thread
Quick Reply: Hardtop vs. sunroof FD for track


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: