Dry sump would only gain you an extra inch or two. The front of the oil pan where it crosses the steering rack is very shallow. My stock F-body pan clears the steering rack by less than two inches.

 

As gnx7 already pointed out, most of the weight of an LS1 sits relatively low. The crank sits lower than the 13b's e-shaft for example. The top part of the motor has a plastic intake and all aluminum heads. And you're forgetting about the weight of the lower and upper intake manifolds on the 13b that sit pretty high in the bay. Take those things off and weigh them...they aren't exactly light. I would be willing to bet that they are around the same weight as the heads and intake on an LS1, or are very close in weight.

 

Lets not forget that the LS1 swap requires the battery moved low into the passenger compartment. With the stock rotory it's high and forward of the front wheels. That thing probibly weighs almost as much as a set of aluminum heads with valves and springs.

 

i just got retuned and now make 398 hp and 410 tq.
with the 2730 lbs curb weight and approx crank hp equalling 460 hp, i have lbs per hp ratio better than new z06 and viper:
me: 2730/460 = 5.93 lbs/hp
viper: 3470/510 hp = 6.80 lbs/HP
C6 z06: 3147/505 hp = 6.23 lbs/HP

 

It doesn't "require" it. I ran a tiny Hawker Genesis battery in the engine bay for a year with only one memorable cranking issue.

 

NICE!!!

 

Even though I took the SuperStock Championship in points this year at my local SCCA Region AutoX, the stock FD, just doesn't have enough low-end torque to compete with the Z06, or the Lotus Elise.

A Z06 or Lotus with a good driver has been consistently 2-seconds faster. I've been trying to keep the REVS up, but oh, is it hard . . .

Too bad a LS1/LT1 powered FD in SCCA AutoX would still not be competitive in it's proper class.

Yes, a SM2 RX7 with highly modified rotary won this year, but we'll see how long that continues.

:-) neil
:-) neil

 

Actually, a Z06 with a ~500whp crate motor won, though it was pretty close. As for highly modified, the RX7 had a bone stock reman with a GT35R single kit. In any case, autox isn't just dependent on power. If you want low end, short gears and a properly sized turbo will give you all you need or can put down.

-Andy

 

hey.. q for the LS1 guys with the nominal weight gain.. what ls1 are you using?.. I know the truck LS1's are iron block.. so i'm just making sure.. thanks

of course.. i could be wrong..

 

We're using the aluminum LSx motors.

The "iron LS1s" are actually engine codes LQ9 and LQ4.

 

LS2 based 402 (a little under 6.6 liters), 500 whp, torque all over. Youre going to have trouble matching that with a turbo rotary, unless its a 20b. You simply cant match that with a peaky 500 whp from a turbo, if both cars are the same - even with a turbo theres no replacement for displacement. Oh, and thats a touch over 90 hp/liter N/A

As far as the weight gain, its minimal to nonexistant, and what weight gain there is is in the engine/transmission, in the middle of the car, and not going to impart much of a handling difference, and it makes so much more torque and power that you wont miss it.

As far as the iron blocks, 10thAELT1 has, what, a 60 lbs heavier *** end than front end? Total Weight? him and a full tank of gas, 2960 lbs. Still has AC and PS too.

 

i wonder how good traction is with an engine like this

 

Mike said he can spin the stock wheels through 5th.

Sounds like it's time for significantly larger wheels before someone gets hurt.

 

sounds like a great engine my buddy talks about LS1's all the time....

hmm maybe ill save and get the RB lightweight housings....and light weight rotors...14lb flywheel in my gutted FC.....i wonder who will be lighter....lmao but anyways....that 100hp LOW END TORQUE wouldnt THAT make the difference? I UNDERSTAND HP doesnt mean much BUT since the FD is turboed and the LS1 is a v8...with 100+hp...doesnt it mean that the LOW END is going to get it every time? since the FD's power band is substantially above the ls1? just wondering?(i think the LS1 swapp has proven itself with tech data i tip my hat!)

awsome car! good luck with ur auto-x season!

 

thanks guys. just an update. even though i'm not an avid drag racer and car isn't set up for drag racing, i went to atco over the weekend with MT ET Street Radials and went 10.97 at 127 mph with a 1.578 short time.

http://www.ponycars.net/atco1097.htm

insane handling from a great chassis and enough power to embarass almost any street car.

 

I dont want to sound mean or anything, but it seems that your torque falls off sharply enough and you are getting more torque than horsepower. If you could put a big cam, larger intake ect. to pull that torque out a couple thousand rpms, it would lay down insane numbers. I mean just pull 410 tq to just 6,000 and you'd have over 468 to the wheels, and a super broad powerband. It all about the horsepower and the broadest powerband.

 

I dont want to sound mean or anything, but it seems that your torque falls off sharply enough and you are getting more torque than horsepower. If you could put a big cam, larger intake ect. to pull that torque out a couple thousand rpms, it would lay down insane numbers. I mean just pull 410 tq to just 6,000 and you'd have over 468 to the wheels, and a super broad powerband. It all about the horsepower and the broadest powerband. (something Nihianthic will never grasp, calling it "peaky" if torque dosent fall on its face.)

 

yeah i hear ya. i have no plans for bigger cam. i'm not building drag car. its road race machine, so spending money on cam and intake is not in it for me. it has enough power to get me into trouble as it is. i'll concentrate on safety and handling and braking. FYI motor was built in 99 with this baby cam because there was no editing software available at the time, so they had to keep it mild. it goes 10's on radials now and that is fast enough for me

 

Yes very true, its very fast as-is, but I guess its like leaving some power on the table, and easliy tapped. But at least it gives you some room to grow in the future. Nice ride at any rate.

 

Is E-Mod where a LS1 powered FD falls into, or something else ?

:-) neil

 

i like autocross and appreciate the skill involved; been doing it for 6 or so years. but since i started doing open track/HPDE, i would choose HPDE over AX every time. so for me, SCCA classing doesn't matter; i got this car for the open track. and when i do AX, its not with SCCA; i AX with www.themclub.net and we have much diff classing structure.

 

I am pretty sure that the new X Prepared coming out this year will be a good class for the RX-(5.)7 L.

 

I predict class domination by V8 FDs!

 

adjusting corner weights can make a big difference to the handling. I did a lot of the ride height, wheel aligement, toe and shocks for Mazda Australia when they were running RX7's in the production class here in Australia. We were alowed to change the shocks and we had adjustable spring platforms. To do a corner weight we checked the tyre pressures we correct and we disconected the sway bars front and rear, then checked the weights and adjusted as best we could trying to keep a sensable ride height. I used the method where if the car had a 49% rear weight I would get the total weight on the right side and aim to get 49% of that weight at the rear and I would do the same for the left. I found the RX7 always settled a little after a change and so I would have to do it a few time to get it right, after a while I worked out how much it would normaly settle and adjusted it to suit. After getting the weights to where you want them you re-attach the sway bars adjusting then so they are not pre-loaded.

~Ian.

 

I just weighed my car at the race track this weekend and figured I'd post results here.

Driver Front = 723 Pass Front = 659
Driver Rear = 715 Pass Rear = 704

Total w/o driver = 2802

Car details:
1993 RX7 R1
stock body, 99 lip, R1 wing
Full tank of gas
[full size Optima] Battery relocated to pass bin
Full interior except spare removed
Running Seq Twins and all accessories (including air pump)
Down pipe, SMB mid pipe, RB cat back
17 x 9 rims all around
Racing Brake BBK