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914World.com _ 914World Garage _ saving weight on a 1.7
Posted by: drewvw May 30 2006, 11:17 AM
With a stock 1.7 how much weight would you have to lose via FG/CF hoods,lids and such to see a performance gain?
This is a purely theorectical question regarding how weight affects the performance of the engine, I am not planning on doing this...
Posted by: Aaron Cox May 30 2006, 11:19 AM
whats your power to weight ratio now?
wont get much better by dropping 50 lbs.....
and FG fits like shit most of the time....
not worth it on a nice street car.... track, definitely
Posted by: drewvw May 30 2006, 11:25 AM
The car is bascially bone stock outside of SS heat exchangers and a bursch exhaust. I figured the weight drop would have to be substantial.
I read in the archives about the FG/CF stuff: Great for racing, bad for street cause they don't look so good and collison is baaaaaad.
I'm just going to have to build myself a 2.0 at some point, or maybe start by driving one first...are they that much quicker, really?
Posted by: Aaron Cox May 30 2006, 11:27 AM
a hot 2.0 or 2056 can make 120 hp.....
your used to a tired 1.7... 70 ish hp....
will almost doubling your car's power with no additional weight make an impact?
yes.
Posted by: Mueller May 30 2006, 11:28 AM
it's just simple math....
let's say your car wieghs 2000 pounds and has 80hp
2000/80 = 25, so you have 25 pounds per 1 hp
remove 100 pounds for 1900/80 = 23.75 pounds per 1 hp
for referance, the early Miatas weigh 2116 with 116 hp, for a 18.24:1 ratio
to get the same hp/pound ratio for your stock 1.7 as the Miata has, you'd have to get your car down to 1459 pounds which is near impossible for a street driven (and safe) 914 
Posted by: drewvw May 30 2006, 11:36 AM
math has never been my forte, so thanks for that mueller.
Heres my problem (besides being bored at work):
This club....you hang out here for awhile and all of a sudden your trying to figure out what engine config you should be gunning for next! Which is a compliment of course...
my 1.7 isn't tired and runs great, was rebuilt by a pro ( ~10K miles on it) and its fun to drive around the city where the roads dont let you go too fast and yet...
well you get the point...aaron ideally I'd like to build a 2056 and probably throw some carbs on it, but I want to stick with the /4. Going to a /6 is too much cost/time/work for me, it would be a bad idea....
Posted by: URY914 May 30 2006, 11:49 AM
My car WAS a stock '73 1.7. 
Posted by: drewvw May 30 2006, 12:00 PM
My car WAS a stock '73 1.7.
when I posted the topic, I assumed you would be the first to "weigh in"
Posted by: lapuwali May 30 2006, 03:12 PM
Turbo...
Posted by: So.Cal.914 May 30 2006, 04:57 PM
Find and build a 2.0, save the 1.7 for a spare.
Posted by: sixerdon May 30 2006, 08:11 PM
OK Drew, try this.
Start with a half tank of gas or less. Leave your top home. Take out your spare and the carpet covered board out. Carpets out. Do you have sound deadening in the engine compartment? Out permanently unless you really do want it. Pump up your tires to 36f/40r. Roll down your windows and go! Tell us if you feel a difference.
Don
Posted by: Mueller May 30 2006, 08:20 PM
OK Drew, try this.
Start with a half tank of gas or less. Leave your top home. Take out your spare and the carpet covered board out. Carpets out. Do you have sound deadening in the engine compartment? Out permanently unless you really do want it. Pump up your tires to 36f/40r. Roll down your windows and go! Tell us if you feel a difference.
Don
Don,
excellent idea !!!
I guess you could wiegh those items as well for testing..
Posted by: Brew May 30 2006, 08:28 PM
well you get the point...aaron ideally I'd like to build a 2056 and probably throw some carbs on it, but I want to stick with the /4. Going to a /6 is too much cost/time/work for me, it would be a bad idea....
Isn't a 2056 a /4?
Posted by: drewvw May 30 2006, 08:56 PM
OK Drew, try this.
Start with a half tank of gas or less. Leave your top home. Take out your spare and the carpet covered board out. Carpets out. Do you have sound deadening in the engine compartment? Out permanently unless you really do want it. Pump up your tires to 36f/40r. Roll down your windows and go! Tell us if you feel a difference.
Don
Hey c'mon! I asked the question more in the interests of science than actually believing it would make a substantial difference.
you sixer guys...so cocky with your 911 engines
Posted by: drewvw May 30 2006, 08:58 PM
well you get the point...aaron ideally I'd like to build a 2056 and probably throw some carbs on it, but I want to stick with the /4. Going to a /6 is too much cost/time/work for me, it would be a bad idea....
Isn't a 2056 a /4?
yes it is...ideally I would build a sweet IV. Six is too much work for me...
Posted by: SirAndy May 30 2006, 09:00 PM
you sixer guys...so cocky with your 911 engines
i think he was serious. if not, he should have been ...
my personal experience:
the less HP, the more you can feel the weight difference in the performance of your car ...
if you have 600HP, you won't feel a 100lbs difference unless you're a pro driver in a full racecar.
in a stock 75HP 1.7L, you *will* feel the difference of 100lbs ...
i'd say, remove all unneeded ballast and take her for a drive and judge for yourself ...
Andy
Posted by: sixerdon May 31 2006, 05:50 AM
Thanks Andy.
BTW. Take out the passenger seat for this run. 30 seconds to remove. No passengers for this run. Do it!!
Don
Posted by: bd1308 May 31 2006, 05:52 AM
Whatever you do, don't carry a 914 engine in the front trunk....
talk about ballast...it was pokey when the engine was in the trunk...
b
Posted by: BK911 May 31 2006, 08:51 AM
stock car: 2000#/80hp = 25#/hp
lightened car: 1900#/80hp = 23.75#/hp
So compare new #/hp to old #: 2000#/23.75 is like having 84hp in a stock car, so about 4hp per 100#'s.
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