Coupe vs Fastback - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

*DSC* · 02-13-2003, 04:20 PM

For racing, which one is better and why?

Looks like all of the factory nissan race cars were fastbacks.
But everybody who races in ITA (dono about s13's in its, have yet to see one) runs a coupe.

Tnord and I were talking about it and just had guesses but no real answers.
Coupe is stiffer/lighter stock vs stock compared to the fastback from everything i've heard.
But given minium weights and a roll cage, it seems like they would be equally stiff and light.
So, since the fastbacks are more aerodynamic, why isn't it the choice for club racers in the US?
Only answer I could come up with is maybe the s13 can't reach its minium weight?

For the factory racing, I guess they have gobs of power and aerodynamics is more important than 30lbs or however much?

If anybody knows or cares to join in on the guessing...

Dousan_PG · 02-13-2003, 04:40 PM

mm one advantage of a fastback is you can get a fiberglass hatch. that would drop a ton of weight....

cant help much otherwise

KiDyNomiTe · 02-13-2003, 05:03 PM

Quote:

Originally posted by dousan36
mm one advantage of a fastback is you can get a fiberglass hatch. that would drop a ton of weight....

cant help much otherwise

I think nissan just has a thing for hatches, they used the Zs too, they were hatches, maybe there is some hidden fact about hatches.

But I also have heard about the coupe bieng stiffer and all.

*DSC* · 02-13-2003, 05:59 PM

Quote:

Originally posted by dousan36
mm one advantage of a fastback is you can get a fiberglass hatch. that would drop a ton of weight....

cant help much otherwise

What class allows a fiberglass hatch though?

tnord · 02-13-2003, 06:54 PM

i think what he means is a lexan window to replace the glass. which he is right, would drop a significant amount of weight from the place it is most hamrful......up top.

Dousan_PG · 02-13-2003, 07:09 PM

ah yes that too
but you can get the whole hatch in fiberglass...

dotn know about what class it is in though, not too keen on that stuff, still learning

240racer · 02-13-2003, 08:12 PM

Isn't it possible to have a complete roll cage in those race cars? If so, then you just use that to get all the stiffness you need. The body is just a body, hatch or coupe. The hatch is more sporty, some might say and that's why they went with it. It is also probably more aerodynamic. Also, there aren't any s14 hatchbacks, so there's only going to be s14 coupe ITA cars. If I had a race car of that caliber, the body would be as few of peices of fiberglas as possible and the structure would just be tube frame. I don't know if that is legal in all those classes, but I'm sure you can get really close by bending rules and such.

Bbandit · 02-14-2003, 03:23 AM

fastback is faster
"fast"back ---> fast!
coupe ---> just coupe (ex: can a have a coupe of coffee please?)

bad joke

2FortyessX · 02-14-2003, 08:55 AM

Quote:

Originally posted by Bbandit
fastback is faster
"fast"back ---> fast!
coupe ---> just coupe (ex: can a have a coupe of coffee please?)

bad joke

agreed

HippoSleek · 02-14-2003, 09:36 AM

Rollcages under SCCA IT rules are only allowed a certain number of attachment points (8) and then only at particular locations. Most 240s that you will see racing today are running in ITA or ITS and follow this rule. The older factory cars and some other efforts existed in the GT2 and GT3 classes where tube frame cars were allowed. Absent a tube frame, there is no way make the hatch as rigid as the coupe.

Also, unlike GT cars, IT cars must use original body panels. Carbon fibre and fibreglass replacement panels are illegal (as are lexan windows). Thus, there is not way to overcome the weight of heavy glass in the hatch. Also, while weight rules may ultimately put both the hatch and the coupe at the same minimum weight, the weight in the hatch is located in a horrible position, relatively (high and at the back of the car).

There is no "bending the rules" in IT -- you will be protested, they will dismantle your car, and you will be disqualified. See, AARC runoffs where MANY top cars were DQ'ed after a visit to tech.

While the fastback might offer a few more mph on the straights, the added weight and weaker chassis make the coupe a better race car for club racing. Where rules are more open and money is no object, the fastback's aero-vantage would make it the winner.

See you next week - hopefully w/ pics of a new toy.

mark

tnord · 02-14-2003, 10:45 AM

and as usual when it comes to questions about classing and rules dealing witht he SCCA.......mark comes through with the answer.

you goin to pick up a miata mark?

Zemus · 02-14-2003, 10:51 AM

Well i hear that coupes the the best because of their lack of weight, but i could say the FB would be easyer to add a roll cage to because of its openness. And its much easyer to gut that whole 2lb if that from the hatch, and its easyer to take out the seats, if that even makes a diffrence

91CRXsiR · 02-26-2003, 01:40 AM

how much does the glass on the hatch weigh? i know my hatch is really heavy. my struts are bad so i have to use a stick to prop up my hatchlid..

are there any negatives to using a lexan windows?

how do they shatter? in shards or large chunks?
and how clear is it? and resistan to heat? or direct sunlight it would suck if it melted in the hot cali sun.

adey · 02-26-2003, 02:35 AM

Wouldn't the better weight distribution of the hatch give it a slight advantage as well?

Pros to hatch: better weight dist. and better aero.
Pros to coupe: lighter and more rigid rear end.

Am I missing anything? just how much more rigid is the coupe, and what difference would this make (if any) that wouldn't at least partially be negated by it's poorer weight distribution?

AKADriver · 02-26-2003, 08:46 AM

Any weight distribution disatvantage there may be is far easier to overcome than a floppy chassis if you're not allowed extensive bracing. A light and stiff 55/45 beats a heavier, higher cg, flexier 53/47 any day.

A51PS13 · 03-07-2003, 11:43 AM

hey i dont know if this is tru i could care less but this dood i know at Stillen said my coupe was 50/50 with the sr20det. Im jus sayin cuz Stillen usually know there shizzel. Either which way.

Coupe Pros: Its Just Better
Hatchback Pros: There are none.

Haha no im jus messin. Maybe Im jus a lil biased haha.

Dousan_PG · 03-07-2003, 11:45 AM

Quote:

Originally posted by A51PS13
Im jus sayin cuz Stillen usually know there shizzel.

you're joking right? LOL

A51PS13 · 03-07-2003, 12:18 PM

well im jus sayin man phil at stillen seemed to know his shizzel when i met him at Area 51. so yeah . Does ne one say hes wrong in that the s13 w/sr20 isnt 5050.

But beyond that coupes r better.haha

N dont hate man i jus dont know shiz about my car man. I only got into nissans in june. I was a Honda man before dood.

Dousan_PG · 03-07-2003, 12:23 PM

stillen knows so much they sell 2 left Z32tt calipers at there garage sales!!!

sells a full set of brake lines for a 240sx yet its too long and all for the rears

i paid 20 bucks for the lines
i didnt get the calipers (already had them)
overcharge on prices for their products.

dont trust stillen! its stealin! they f'd my friends car too when they worked on it!

and Area51, arent they going out of business?
i went there once, um...rip off!

and the SR isnt much lighter then the KA. its a MYTH

i aint hating on you, just dont believe businesses who are in it for $$$$ rather then helping people.

ruf · 03-07-2003, 02:10 PM

Quote:

Originally posted by DSC
Looks like all of the factory nissan race cars were fastbacks.

What gave you this idea? I don't think I've EVER seen a factory 180SX race car.

As for the Stillen, I know a mechanic that used to wrench on the Stillen 300Z IMSA team. The only reason they used the Stillen bodywork was that some weird loophole in the rules allowed them a weight break if they ran it. No one really liked it much. I personally hate Stillen. I buy all my AP stuff direct. I won't even give them the pleasure of putting a dumb Stillen sticker on my calipers.

A51PS13 · 03-08-2003, 01:24 PM

Well. I dont buy from Stillen. I buy from Phil. N dood Stillens good for some things man. Find somebody else that can tell me the color of the tach wire off the ECU for the G35(we were installing an AFC ) not even the freakin techs at the dealership knew. Oh and we have the wiring diagram also. it dont say. As for Area 51 man yeah My boi shut down the shop cuz he wanted to get out of it. Too bad u got ripped off though, i got hooked up. But cmon if ur not cool with somebody in the industry ur gonna get ripped off thats just how it is

DamnedButDetermined · 03-08-2003, 04:52 PM

Quote:

Originally posted by dousan36
i aint hating on you, just dont believe businesses who are in it for $$$$ rather then helping people.

Sorry to point this out, but EVERY BUSINESS is in it for $$$$!

Learned that one in collage

Dousan_PG · 03-08-2003, 07:39 PM

Quote:

Originally posted by DamnedButDetermined
Sorry to point this out, but EVERY BUSINESS is in it for $$$$!

Learned that one in collage

learned that but not how to spell

college

not every business is ONLY for money
some do it to help people as well. at least the businesses i associate myself with. then again, i get such great prices, must be just me!

Dousan_PG · 03-08-2003, 07:40 PM

Quote:

Originally posted by A51PS13
My boi shut down the shop cuz he wanted to get out of it. Too bad u got ripped off though, i got hooked up. But cmon if ur not cool with somebody in the industry ur gonna get ripped off thats just how it is

nah i NEVER went at area51 for buying stuff.

just walking in their show room i was like 'i gotta get the **** outta here'
hahah

btw, i havent ever paid retail for any product on my 240sx. except gas and tires. everything else was dealer cost or below. or free. sponsors are cool.

AKADriver · 03-08-2003, 08:28 PM

Quote:

Originally posted by ruf
What gave you this idea? I don't think I've EVER seen a factory 180SX race car.

All the 240SX IMSA cars were fastbacks.

But, those were tube framed cars.

adey · 03-08-2003, 10:29 PM

Quote:

Originally posted by dousan36
i havent ever paid retail for any product on my 240sx. except gas and tires.

As a drifter, I think those are precisely the two things that you'd save the most money on paying below "market" price.

I think you need a tire sponsor. Gas, well, that's a tough one unless you can convince 76 that you're worth their gas!!

wherezmytofu · 03-09-2003, 12:48 PM

its a simple fact that the coupe has a cool rating of 8.9 some people quote it as a full 9.2, i ran it thry the coolno machine and got a 8.96 but i hadnt wash the car in a while, anyhow the fastback is only rated as 7.8, max i've seen stock is 8.3 and that was pushing it

DamnedButDetermined · 03-09-2003, 01:49 PM

Quote:

Originally posted by dousan36
learned that but not how to spell

college

not every business is ONLY for money
some do it to help people as well. at least the businesses i associate myself with. then again, i get such great prices, must be just me!

I was kidding about the collage thing, and there isn't a single SMART business owner out there that doesn't want to make money. There would be no point in offering your experience if you weren't making any money. Racing Car Owners are a totally different thing...they are crazy about racing so they are in it to loose money!

I was trying to be a smart ass

wherezmytofu · 03-09-2003, 02:39 PM

Quote:

Originally posted by DamnedButDetermined
I was kidding about the collage thing, and there isn't a single SMART business owner out there that doesn't want to make money. There would be no point in offering your experience if you weren't making any money. Racing Car Owners are a totally different thing...they are crazy about racing so they are in it to loose money!

I was trying to be a smart ass

i got that uber-fly college edgumiocation!

DamnedButDetermined · 03-09-2003, 07:20 PM

Quote:

Originally posted by wherezmytofu
i got that uber-fly college edgumiocation!

maybe i didn't go to college long enough, b/c i can't tell if you are aking fun of me or sidding with me? hehehehehehe

02-13-2003, 04:20 PM	#1
DSC New Title Join Date: Aug 2001 Location: VA Posts: 3,454 Trader Rating: (0) Feedback Score: 0 reviews	Coupe vs Fastback For racing, which one is better and why? Looks like all of the factory nissan race cars were fastbacks. But everybody who races in ITA (dono about s13's in its, have yet to see one) runs a coupe. Tnord and I were talking about it and just had guesses but no real answers. Coupe is stiffer/lighter stock vs stock compared to the fastback from everything i've heard. But given minium weights and a roll cage, it seems like they would be equally stiff and light. So, since the fastbacks are more aerodynamic, why isn't it the choice for club racers in the US? Only answer I could come up with is maybe the s13 can't reach its minium weight? For the factory racing, I guess they have gobs of power and aerodynamics is more important than 30lbs or however much? If anybody knows or cares to join in on the guessing... __________________

02-13-2003, 04:40 PM	#2
Dousan_PG Post Whore! Join Date: May 2002 Location: Orange County, California Age: 46 Posts: 16,640 Trader Rating: (23) Rides Gallery: Dousan_PG Feedback Score: 23 reviews	mm one advantage of a fastback is you can get a fiberglass hatch. that would drop a ton of weight.... cant help much otherwise __________________ Aaron Pink GodziRa www.geocities.com/pink_godzira

02-13-2003, 07:09 PM	#6
Dousan_PG Post Whore! Join Date: May 2002 Location: Orange County, California Age: 46 Posts: 16,640 Trader Rating: (23) Rides Gallery: Dousan_PG Feedback Score: 23 reviews	ah yes that too but you can get the whole hatch in fiberglass... dotn know about what class it is in though, not too keen on that stuff, still learning __________________ Aaron Pink GodziRa www.geocities.com/pink_godzira

02-13-2003, 08:12 PM	#7
240racer Zilvia Junkie Join Date: Nov 2001 Location: Minneapolis, MN Age: 46 Posts: 574 Trader Rating: (0) Feedback Score: 0 reviews	Isn't it possible to have a complete roll cage in those race cars? If so, then you just use that to get all the stiffness you need. The body is just a body, hatch or coupe. The hatch is more sporty, some might say and that's why they went with it. It is also probably more aerodynamic. Also, there aren't any s14 hatchbacks, so there's only going to be s14 coupe ITA cars. If I had a race car of that caliber, the body would be as few of peices of fiberglas as possible and the structure would just be tube frame. I don't know if that is legal in all those classes, but I'm sure you can get really close by bending rules and such. __________________ Adam '89 coupe KA24DE+T 14.1 @ 104 MPH '88 Celica All-Trac turbo stock, but no more ecu codes!!

02-14-2003, 03:23 AM	#8
Bbandit Post Whore! Join Date: Mar 2002 Location: Texas and now Jakarta Age: 43 Posts: 2,674 Trader Rating: (0) Rides Gallery: Bbandit Feedback Score: 0 reviews	fastback is faster "fast"back ---> fast! coupe ---> just coupe (ex: can a have a coupe of coffee please?) bad joke __________________ ==>>TGL GARAGE<<==.. RIP! S13 coupe KA-T @ 0.5 Bar = SOLD! A31 Cefiro + SR = Current

02-13-2003, 06:54 PM	#5
tnord Nissanaholic! Join Date: Dec 2001 Posts: 1,975 Trader Rating: (0) Feedback Score: 0 reviews	i think what he means is a lexan window to replace the glass. which he is right, would drop a significant amount of weight from the place it is most hamrful......up top.

02-14-2003, 09:36 AM	#10
HippoSleek Nissanaholic! Join Date: Aug 2001 Location: elsewhere Posts: 2,081 Trader Rating: (0) Feedback Score: 0 reviews	Rollcages under SCCA IT rules are only allowed a certain number of attachment points (8) and then only at particular locations. Most 240s that you will see racing today are running in ITA or ITS and follow this rule. The older factory cars and some other efforts existed in the GT2 and GT3 classes where tube frame cars were allowed. Absent a tube frame, there is no way make the hatch as rigid as the coupe. Also, unlike GT cars, IT cars must use original body panels. Carbon fibre and fibreglass replacement panels are illegal (as are lexan windows). Thus, there is not way to overcome the weight of heavy glass in the hatch. Also, while weight rules may ultimately put both the hatch and the coupe at the same minimum weight, the weight in the hatch is located in a horrible position, relatively (high and at the back of the car). There is no "bending the rules" in IT -- you will be protested, they will dismantle your car, and you will be disqualified. See, AARC runoffs where MANY top cars were DQ'ed after a visit to tech. While the fastback might offer a few more mph on the straights, the added weight and weaker chassis make the coupe a better race car for club racing. Where rules are more open and money is no object, the fastback's aero-vantage would make it the winner. See you next week - hopefully w/ pics of a new toy. mark

02-14-2003, 10:45 AM	#11
tnord Nissanaholic! Join Date: Dec 2001 Posts: 1,975 Trader Rating: (0) Feedback Score: 0 reviews	and as usual when it comes to questions about classing and rules dealing witht he SCCA.......mark comes through with the answer. you goin to pick up a miata mark?

02-14-2003, 10:51 AM	#12
Zemus Nissanaholic! Join Date: Oct 2001 Location: Minneapols Age: 40 Posts: 2,268 Trader Rating: (0) Rides Gallery: Zemus Feedback Score: 0 reviews	Well i hear that coupes the the best because of their lack of weight, but i could say the FB would be easyer to add a roll cage to because of its openness. And its much easyer to gut that whole 2lb if that from the hatch, and its easyer to take out the seats, if that even makes a diffrence __________________ \|Ziptied.com\|Hybrid Z\|D-Town Forum\|Clubfr.net\| Last edited by Zemus; 02-14-2003 at 12:03 PM..

02-26-2003, 01:40 AM	#13
91CRXsiR Nissanaholic! Join Date: Oct 2001 Location: City of Industry, CA [626] Age: 42 Posts: 2,092 Trader Rating: (1) Feedback Score: 1 reviews	how much does the glass on the hatch weigh? i know my hatch is really heavy. my struts are bad so i have to use a stick to prop up my hatchlid.. are there any negatives to using a lexan windows? how do they shatter? in shards or large chunks? and how clear is it? and resistan to heat? or direct sunlight it would suck if it melted in the hot cali sun.

02-26-2003, 02:35 AM	#14
adey Post Whore! Join Date: Mar 2002 Location: Hong Kong Posts: 3,072 Trader Rating: (0) Feedback Score: 0 reviews	Wouldn't the better weight distribution of the hatch give it a slight advantage as well? Pros to hatch: better weight dist. and better aero. Pros to coupe: lighter and more rigid rear end. Am I missing anything? just how much more rigid is the coupe, and what difference would this make (if any) that wouldn't at least partially be negated by it's poorer weight distribution? __________________ Instagram: @SX180HKG

02-26-2003, 08:46 AM	#15
AKADriver Post Whore! Join Date: May 2002 Location: Springfield, VA Age: 43 Posts: 3,517 Trader Rating: (1) Feedback Score: 1 reviews	Any weight distribution disatvantage there may be is far easier to overcome than a floppy chassis if you're not allowed extensive bracing. A light and stiff 55/45 beats a heavier, higher cg, flexier 53/47 any day.

03-07-2003, 11:43 AM	#16
A51PS13 Leaky Injector Join Date: Nov 2002 Posts: 54 Trader Rating: (0) Feedback Score: 0 reviews	hey i dont know if this is tru i could care less but this dood i know at Stillen said my coupe was 50/50 with the sr20det. Im jus sayin cuz Stillen usually know there shizzel. Either which way. Coupe Pros: Its Just Better Hatchback Pros: There are none. Haha no im jus messin. Maybe Im jus a lil biased haha. __________________ Area 51 PS13 Silvia Conversion 230hp 234lb/ft torque to the wheels 11 lbs of boost

03-07-2003, 12:18 PM	#18
A51PS13 Leaky Injector Join Date: Nov 2002 Posts: 54 Trader Rating: (0) Feedback Score: 0 reviews	well im jus sayin man phil at stillen seemed to know his shizzel when i met him at Area 51. so yeah . Does ne one say hes wrong in that the s13 w/sr20 isnt 5050. But beyond that coupes r better.haha N dont hate man i jus dont know shiz about my car man. I only got into nissans in june. I was a Honda man before dood. __________________ Area 51 PS13 Silvia Conversion 230hp 234lb/ft torque to the wheels 11 lbs of boost

03-07-2003, 12:23 PM	#19
Dousan_PG Post Whore! Join Date: May 2002 Location: Orange County, California Age: 46 Posts: 16,640 Trader Rating: (23) Rides Gallery: Dousan_PG Feedback Score: 23 reviews	stillen knows so much they sell 2 left Z32tt calipers at there garage sales!!! sells a full set of brake lines for a 240sx yet its too long and all for the rears i paid 20 bucks for the lines i didnt get the calipers (already had them) overcharge on prices for their products. dont trust stillen! its stealin! they f'd my friends car too when they worked on it! and Area51, arent they going out of business? i went there once, um...rip off! and the SR isnt much lighter then the KA. its a MYTH i aint hating on you, just dont believe businesses who are in it for $$$$ rather then helping people. __________________ Aaron Pink GodziRa www.geocities.com/pink_godzira

03-08-2003, 01:24 PM	#21
A51PS13 Leaky Injector Join Date: Nov 2002 Posts: 54 Trader Rating: (0) Feedback Score: 0 reviews	Well. I dont buy from Stillen. I buy from Phil. N dood Stillens good for some things man. Find somebody else that can tell me the color of the tach wire off the ECU for the G35(we were installing an AFC ) not even the freakin techs at the dealership knew. Oh and we have the wiring diagram also. it dont say. As for Area 51 man yeah My boi shut down the shop cuz he wanted to get out of it. Too bad u got ripped off though, i got hooked up. But cmon if ur not cool with somebody in the industry ur gonna get ripped off thats just how it is __________________ Area 51 PS13 Silvia Conversion 230hp 234lb/ft torque to the wheels 11 lbs of boost

03-09-2003, 12:48 PM	#27
wherezmytofu BANNED Join Date: Nov 2001 Posts: 1,873 Trader Rating: (0) Feedback Score: 0 reviews	its a simple fact that the coupe has a cool rating of 8.9 some people quote it as a full 9.2, i ran it thry the coolno machine and got a 8.96 but i hadnt wash the car in a while, anyhow the fastback is only rated as 7.8, max i've seen stock is 8.3 and that was pushing it