Mazda Rotary Club

General => General Technical => Topic started by: DR SCHNITZEL on December 22, 2009, 01:08:10 PM

Title: Has anyone on here weighed...
Post by: DR SCHNITZEL on December 22, 2009, 01:08:10 PM
an fd engine with all the trimmings on and a V8 with all the trimmings?
 
What are the weight differences.
Title: Has anyone on here weighed...
Post by: BlitzBoy on December 22, 2009, 02:09:54 PM
yes this has been done before, even with the twin turbos the 13B is still lighter , let me find the weights one second caller
Title: Has anyone on here weighed...
Post by: BlitzBoy on December 22, 2009, 02:33:15 PM
Here we are

LS V8 (LS6 in this example) dressed = 208 kilos
13B rew dressed with twins = 150 kilos

so the 13b REW is lighter by approx 50 kilos, in single turbo form it would be slightly lighter still
Title: Has anyone on here weighed...
Post by: DR SCHNITZEL on December 22, 2009, 03:18:30 PM
Just our mate off redline magazine reported that the rx7 lump is heavier than a V8. Would he be talking about another v8 ? LS1 perhaps. Or maybe out of his hat?
Title: Has anyone on here weighed...
Post by: BlitzBoy on December 22, 2009, 03:35:31 PM
talking out of his hat.
The figures I have given you are actual real weights, taken by people who own the lumps and weighed them and GM data.

All the LS models (ignoring a iron block model) are aluminium, and weigh from 205 kilos to 215 depending on ancillaries fitted

A 13B fitted to the mentioned writer of redline and owner of a FC is lighter still due to the turbo and manifold weights being lighter then the rew twin turbo pack.

The lightest 13B is the one fitted to the rx8 115 kilos fully dressed (plastic intake manifold and no turbo and manufacturing differences in the plates)
Title: Has anyone on here weighed...
Post by: turbo boy on December 22, 2009, 04:00:32 PM
So for the hijack, but what about an na 4rotor or na triple?
Title: Has anyone on here weighed...
Post by: BlitzBoy on December 22, 2009, 04:12:42 PM
20B fully dressed is slightly heavier.

To negate some of the weight differences, the LS motors fitted to rx7s have the AC pump and system removed. One example Stock Rx7 touring 255 versus the same car (owner doing the conversion) with the LS motor fitted (AC removed) , the LS engined car was only 30 kilos heavier, but obviously HP per tonne the LS is much higher.

But of course if the AC pump was removed before hand before the conversion it would have showed up the 50 kilo difference as shown before.

There was only a slight change in difference to the 50:50 weight distrubution but not much in it.

But the cost of the conversion is high, Id rather keep the rotary a modify to 350bhp for much less money.

The conversion has it plus points, better MPG and more torque low down, but revs lower (you need to look at gearing to correct this so you dont lose top end speed)
But to me its not an RX any more, just call it a Mazda 7 lol
Title: Has anyone on here weighed...
Post by: jackaleks on December 22, 2009, 04:14:19 PM
Wikipedia (http://en.wikipedia.org/wiki/GM_LS_engine) has some good info on the LS motors, like which ones are all ali and which are iron block + ali head. also stuff like stroke, bore and displacement as well as a bunch of other useless facts that only apply to piston engines :)
Title: Has anyone on here weighed...
Post by: turbo boy on December 22, 2009, 04:36:46 PM
Very interesting, cheers for that
Title: Has anyone on here weighed...
Post by: DR SCHNITZEL on December 23, 2009, 11:31:31 AM
I wonder then what my engine weighs with everything removed pas air pump, now single tub. compared to an ls engine with no emmisions (ready to drop in) You think 30kg less of maybe 40 to 50? those v8s look huge in the bay
Title: Has anyone on here weighed...
Post by: SiH on December 23, 2009, 11:45:53 AM
Don\'t forget that for a 13b with either twin or single tub, you need to add in the weight of the intercooler and associated piping. For a single you need to add on the weight of a ex-wg and piping as well.
Title: Has anyone on here weighed...
Post by: BlitzBoy on December 23, 2009, 11:46:18 AM
I would say single turbo FDs with all the AC and twin turbo gubbins removed is probably 60 kilos lighter then a LS
Title: Has anyone on here weighed...
Post by: Spartacus on December 23, 2009, 02:37:35 PM
From what I\'ve read the average US swap (as they tend to keep their AC as the plumbing is much easier for LHD) works out around 20kg heavier all in. But saying that, while the conversion is being done it\'s all too easy to add or subtract weight due to changes that are not directly related to the swap, i.e. big brakes, smaller battery etc etc. When I did mine I started to weigh everything I took off the car and everything I put back on it but it didn’t last very long. Either way the weight doesn’t seem to make any difference so I don’t think it\'s really worth bothering about unless you want a super lightweight car in which case there’s always options to use carbon fibre bits.
Title: Has anyone on here weighed...
Post by: BlitzBoy on December 23, 2009, 03:04:53 PM
I\'m aiming to trim down the car 1000 kg even after the cage is fitted, although the cage will add weight it will let me take out the safety bars out of the doors and trim the door weight off.

I think the point is you dont do a LS conversion to save weight, you do it for more mpg and low down torque figures and ease of maintanence.
Although if those guys in the US are saying only 20 kilos are added I think they are being over optomistic in their weighing in trying to win an arguement as actual weight figures of the fully dressed engines dont lie (50 kilos).

But horses for courses, people can do what ever they want to their cars.

But you cant beat that high rpm noise of a high powered rotary mmmm ;)
Title: Has anyone on here weighed...
Post by: DR SCHNITZEL on December 23, 2009, 03:26:30 PM
1000kg, wowzers! How easy will that be to acheive. Id love to get mine down to that weight. Is your car drag only blitz?
Title: Has anyone on here weighed...
Post by: BlitzBoy on December 23, 2009, 03:37:01 PM
well road and drag, its all street legal I drive it at weekends weather permitting, u need light doors, fpr or carbon boot lid, plastic windows, no carpet, no sound deadning, no interior plastics, no rear seats, lightweight bucket seats for the front, ideally get rid of the electric windows to manual, light wheels, smaller battery
Title: Has anyone on here weighed...
Post by: DR SCHNITZEL on December 23, 2009, 03:48:44 PM
I could do all that apart from the interior. It looks nasty standard (well mine does) but with it all stripped out it wouldnt be a pussy wagon anymore. Not that i get any.
Title: Has anyone on here weighed...
Post by: BlitzBoy on December 23, 2009, 03:55:46 PM
also deletion of the Airpump,AC system included the radiators,matrix and lines
Title: Has anyone on here weighed...
Post by: m1tch on December 25, 2009, 10:14:04 PM
Quote from: DR SCHNITZEL;6611561000kg, wowzers! How easy will that be to acheive. Id love to get mine down to that weight. Is your car drag only blitz?

A stock FC3S turbo II coupe is 1191kgs lol
Title: Has anyone on here weighed...
Post by: DR SCHNITZEL on December 26, 2009, 12:57:48 AM
And an FD is 50kg more? I must have rid 50 kg off mine going single tub and removing spare wheel and a/c pas, air pump etc
Title: Has anyone on here weighed...
Post by: RobMatthews on December 26, 2009, 08:23:46 AM
blitzboy what mechinism did you use for the manual windows, i was gonna loose my fd\'s electric and just bolt in plastic with a slider kit but think it would be better to have it go up and down?
Title: Has anyone on here weighed...
Post by: turbotoaster on December 26, 2009, 04:59:17 PM
where do you get your light doors from, i know where to get the bonnet and boot from, maybe atomicrex as im sure he mentioned hes got his down to 972kg now
Title: Has anyone on here weighed...
Post by: BlitzBoy on December 27, 2009, 12:34:26 AM
have not got a manual mechanism yet, will be experimenting.
You make your own light doors with a angle grinder lol
Carbon doors are so expensive, Seibon make carbon doors
Title: Has anyone on here weighed...
Post by: m1tch on December 27, 2009, 09:41:48 AM
RHDJapan sell CF doors for an FC, I think they are about a grand each!
Title: Has anyone on here weighed...
Post by: marco on December 27, 2009, 11:04:14 AM
Atomic make their own carbon doors, but won\'t sell them to you unless you have a decent roll cage. Price wise, I doubt they are cheap (going off the carbon bits I have bought off them) but they will be very good quality.