LS1 FD corner weights versus stock FD
 

I weighed both cars over the weekend at our autocross event at giants stadium. Both cars had spare removed. Both had almost full tanks of gas but my car has a reduced capacity tank which holds 5 gallons less (5 gallons at 8 lbs/gallon = 40 lbs). Both had stock 16 x 8 rims but i had 245-45-16's Yok AO32R's and rotary had 265-45-16 Kumho ecsta v700's. My car is missing AC, PS and ABS. My battery is in bin on passenger side whereas stock RX7 has battery in original position up front. Bottom line is mine weighed about 15 lbs more but had a better weight distribution of 50.5/49.5 front to rear and his stock RX7 was 53/47:
--------------LS1 ------- Rotary
Left Front: 684 ------- 718
Right Front: 695 ------- 718
Total Front: 1379 ------- 1436

Left Rear: 705 ------- 660
Right Rear: 645 ------- 618
Total Rear: 1350 ------- 1278
TOTAL: 2729 ------- 2714
% over Front: .505 ------- .530
% over Rear: .495 ------- .470

Yes, the rotaty places about 55 lbs more over the front tires!!! incredible!!

the owner of the stock RX7 was my passenger on the last run; listen to his comments at the very end:
http://207.127.219.37/video/AX.wmv

hmm now if you had ps, ac, and abs like he had, i wonder what you would weight then, and with the battery in the stock location.

well that 55 lb is easy in ac,ps,abs, and a battery. so when he has all that removed and moved re weigh them

Agreed. At a minimum that's 50lbs, probably a lot closer to 100lb, worth of stuff. The LS1 is a good choice as far as weight if you feel you have to do something like this. But this is an apples and oranges comparison to say the least.

Not to mention if the rotary had a lightweight aftermarket downpipe and take off the air pump, the weight difference would've been more than 100 lbs.

Just weighed my old ls1 p/s pump and ac compressor. 7 pounds and 15 pounds on a bathroom scale. Woneder how much the lines, abs unit, fluid, and ac condensor would add? My guess would be 25 lbs.

Well maybe if he did that, and then figured out a way to add 150whp without sacrificing low end grunt he wouldn't get dragged around the course like he did. lol

Is the ls1 car a touring model?

The RX-7 could remove this weight from the front...

-35 lbs battery to back
-20 lbs air pump
-38 lbs power steering & A/C
-10 lbs lightweight pulleys & flywheel
-15 lbs SS downpipe or -25+ lbs single turbo conversion
---------
-118+ lbs easy

What do you have left to take off from the front? Go troll somewhere else.

Funny...right underneath "Race Car Tech" it says "Discuss anything related to road racing and auto X." as what is to be posted in this section. Funny how it doesn't say post anything related to "rotary" road racing and autox. So I fail to see how posting his results along with another RX7 owner's impressions could be classified as "trolling."

I've stripped a 94 and shiped most of those parts so I know your way off on everything but the batery. ;)

I can remember when Jimlab first started his conversion and told folks of how close the weight would be...

Chalk another one up for ol Jimboy. :D

no sunroof in all of his pics

hi, i put the vid on another server for faster download:
http://scott.ohyesh.com/videos/ax.wmv

i know its not true apples to apples, but its as close as i could get :) i posted the event in northeast section but no one turned out besides this regular (non-rx7club) guy. its accurate info that is useful and not widely known. my car is a base model, no bose, no sunroof, but i don't know what trim its called in rx7 speak (base?). he's not going to change or remove those items you guys mentioned because he races in SCCA "SS" class (its a stock car class).

i'm sure you all read the other threads that turn ugly. this is pure technical stuff.
so i just have to figure out how to get ABS installed since the whole system was removed. i do see its value for autocross, although i didn't lock up on the road course days.

So the question that lingers: Which car was faster in the Autocross?

I'll update with official times when they are released, but my fastest time was 54.0 and his was 56.0. His tires (265-45-16 kumbo ecsta v700) were way better than mine (yok AO32R 245-45-16 Hard compound), no comparision. they were wider and stickier. My yok's are hard compound and are better on road courses than autocross. He is SCCA SS class driver that is original owner of the car, which is 93 R1. He races full season and competes in Kopeka, but this was my first autocross of the year!! and my first time ever autocrossing any RX7. He has stock R1 springs (stiffer than my stock non-R1 springs?) and $2000 koni custom valved double adjustable shocks (tripoint) and i have 13 year old stock units. The lack of ABS in my car definitely hurt my times as the video reflects constant right front tire lockup (dusty course, need new bleed because i just installed new master, need to adjust proportioning valve, who knows). He loved the car and how it felt on the course so that means a lot coming from a die hard rotary owner/racer.

People go so far out of there way to argue against the weight of the LS1 :rolleyes:

Is it not safe to say that regardless of airpumps, battery location, downpipes etc that an LS1 FD has no real weight disadvantage compared to an FD with any amount of engine mods? If you think not then I say you're just being argumentative and looking for any excuse to bash the LS1. Every guy I know with some real FD driving experience has been floored by the performance of the LS1 cars.

I could tell that was Sandro when I heard his voice on the video.
One important thing not mentioned: the E-mod index is a killer.
Point-->13b rew or any other Mazda engine in SM2.

finky, yes that is sandro. awesome guy! he wanted me to use his tires after i gave him a ride because mine were so much less effective. maybe improvement of 1 to 2 more seconds? who knows. lets not go there :) i would have but i left early for wedding.

The LS1 haters don't like it because it's not SM2 legal? No way.

GJ 2mchpwr :) I have auto-xed my LS1 FD once already and it was a blast. Just to back you up, here's my car corner weighted before and after the swap WITH ac, ps, abs:

1993 touring

Before swap

LF 729 RF 695
LR 705 RR 692

Total--2821lbs

After swap 1999 ls1/t56 trans ac, abs, power steering

LF 748 RF 717
LR 683 RR 700

Total weight 2848lbs

Weight gain only 27lbs

fwiw, i was going to come but couldn't make it. :(

Cant argue with the facts... the Ls1 OWNS~!

Hey finky, this is Malik with the ex-red LS1 TII :)

Yeah, e-mod index kills but it was just too much fun to drive my car at the Auburn Hills AutoX so I for one wasn't that concerned. I just wanted to have some fun, which is why I'm building the successor, I'm pretty sure I'll never develop my driving skills enough to compete in a class anyway :) And it's still fun to compare times with other people from other classes, and just as valid no matter what the index puts you at in the end. A faster car is a faster car, no matter what it has in it. And just to stir things up, finky's car was way faster around than mine (driving skill and tires probably had a lot to do with that) so people shouldn't just assume you're going to be faster at AutoX because you have an LS1 in it :D

Most of the weight data comes from here...

http://www.mantissaconsulting.com/et...eight_data.htm

It's not just the parts themselves but brackets, hoses, emmissions, etc that aren't needed when the main part is removed. I have used a scale to confirm the downpipe, pulleys+flywheel and battery myself. Everything else seems reasonable to me.

Some people like to compare apples to oranges. The fact is the rotary engine is lighter than an LS1 even if it's not a lot. It's pretty dumb to post how my stripped down LS1 RX-7 weighs less than a more stock RX-7. It's kind of like saying how weak those Corvettes are because my modded RX-7 embarassed a stock Vette. There in is the trolling. Talking about how the LS1 RX-7 did at the autocross and the corner weights is fine though.

matt hey, are you calling ME a troll? i thought my post was very informative. i left nothing out. i gave the facts and the weights so everyone can read what was in each car. no surprises. i keep reading how much more the ls1 weighs and it kills the handling of the car. my goal was just to show that when properly executed, that is not the case.