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dyno and weigh in day for my RX-7 V8!

Posted: September 2nd, 2005, 5:56 pm
by mattster
my friends at MX-3.com, took the car to the dynojet and scale today, i had to do it before i leave for fall semester tommorrow. i'm quite happy with the results, the first 2 runs were on my battery only (still no alternator) and the final run was with a charger on it. looks like with a full battery my car runs a lil better . the engine is internally stock, with headers, intake, and wires only. the technicians were pretty impressed with my numbers, they said that the car sounded quite healthy. keep in mind that there are no mufflers either. enough blabbing. attached is the printout... booya! the 283.6 hp is at the wheels, and can be approximated to 340 hp at the crank.

Image

the car weighed in at 2750#, that was with a 1/4 tank of gas, no mufflers and no bumper. we will say 2800-2850# with the mufflers and bumper included. i would say a good estimate of the track weight is 3000 - 3200# that's with me and a full tank of gas, that leads to a pretty good power to weight ratio of under 10 very easily.

hopefully some vids... soon?

Posted: September 2nd, 2005, 6:05 pm
by mattster

Posted: September 3rd, 2005, 12:49 am
by XxantwawnxX
you really think your gonna get under 10? thats crazy...

Posted: September 3rd, 2005, 12:55 am
by papa roached
he said power to weight ratio of under 10

Posted: September 3rd, 2005, 1:40 am
by Juans_93_MX3
Rotary? Of course not!!
A rotary making that much torque :lol:
When pigs fly!

Nice car
You plan to do anything next on teh V8?
Heads & Cam? SuperCharger?

Posted: September 3rd, 2005, 2:04 am
by mattster
ya, i was saying power to weight ratio is under 10 lbs/hp, that was kind of a goal for me when i started the project. i would be happy with a high 12 in the 1/4 mile. as far as the future for my car, i would like to swap the engine into a nicer chassis maybe next summer. the chassis it's in right now is in very poor condition, and it would be cheaper just to buy a new! it would be ideal to find an S5 (89-91) with a TII rearend for added confindence. while the engine is out i would like to put a head and cam combo most definately, lloyd elliot seems to be a popular kit for the LT1, i am thinking in the range of 400 whp. i also would like to get some decent tires on, some traction in 1st gear would be a nice thing. thanks for the compliments, i have a video taken now, but i am not sure i will post it because i suck at driving, and 1/2 of the ride is into the sun :(.

Posted: September 3rd, 2005, 11:09 pm
by johnboi85
very impressing numbers. is that 350 small block an lt1? those numbers don't reflect an lt1. what motor is taht?

Posted: September 4th, 2005, 12:41 am
by Juans_93_MX3
buying new chassis?
How much do you think it will run you on costs?

Posted: September 4th, 2005, 12:51 am
by DavidOS
Juans_93_MX3 wrote:Rotary? Of course not!!
A rotary making that much torque :lol:
When pigs fly!

Nice car
You plan to do anything next on teh V8?
Heads & Cam? SuperCharger?
I wouldnt say that there is the 787b,r26b, and the 20b turb rotor engines.
even the 13b can put down good #s

Posted: September 4th, 2005, 12:59 am
by nope-mx3
RB26 is an inline six cylinder from the Skyline GTR.

nope-mx3

Posted: September 4th, 2005, 1:01 am
by XxantwawnxX
papa roached wrote:he said power to weight ratio of under 10
wow my bad. cause i ws liek no way is he getting under t10.

Posted: September 4th, 2005, 1:17 am
by DavidOS
nope-mx3 wrote:RB26 is an inline six cylinder from the Skyline GTR.

nope-mx3

To a certain extent the USA's IMSA GTP series is very similar to LeMans style racing and the RX-792P carried the rotary flag for a while.
The R26B used in this car was down a little in power and torque, 650bhp@8500rpm, 570Nm/420ftlb@6500rpm

these numbers look respectable to me.... rb26 is skyline, r26b is mazda

Posted: September 4th, 2005, 2:40 am
by V8KOMX3
Rotory power is great but I guess the v8 will do lol

Posted: September 4th, 2005, 10:42 pm
by mattster
yup, a respectable S5 chassis should run me about 800-1000$. then i will sell the drive train for about 400$ to some rotary nut who is looking to have an extra to tinker with. the old chassis will be parted out and taken to a u-wrench it type place to offset the cost a little. the engine IS an LT1, i know the numbers are very high for an LT1, i am quite happy that i landed such a healthy V8. anyway, i will of course keep my friends at the MX-3 forum updated as much as i can with the progress. i am back in michigan now for the fall semester, i will be back around christmas.

Posted: September 5th, 2005, 1:55 am
by Rick Johnson
That is awesome, did you buy a kit to get the motor to bolt in? Are you going auto or manual? I drove a 04 vette a few months back and I must say v8's aren't so bad afterall :D