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-   -   1974 13b-re Nova (https://www.rx7club.com/old-school-other-rotary-63/1974-13b-re-nova-727207/)

13brenova 02-05-12 05:37 PM


Originally Posted by Rotor_Venom08 (Post 10966706)
another great project and i didnt realize that you were in houston? i gotta see this beast!

Any time!

Rotor_Venom08 02-05-12 07:21 PM


Originally Posted by 13brenova (Post 10967155)
Any time!

you goto any of the club meetings? im not sure we've met before

13brenova 02-05-12 08:39 PM

Oh yeah............the track got rained out this Sat. I've got it lined up for next Sat. and if it rains, the next Sat.

DoritoPower 02-05-12 09:34 PM

You are my hero...Seriously. I have a notchback Foxbody Mustang that I've often thought about throwing a rotary into. Props for doing it right!

Frankenrex 02-06-12 12:49 PM


Originally Posted by DoritoPower (Post 10967476)
You are my hero...Seriously. I have a notchback Foxbody Mustang that I've often thought about throwing a rotary into. Props for doing it right!

One up him and put a 20B in the 'Stang! :)
Heck, even NA would be interesting.

DoritoPower 02-06-12 05:38 PM


Originally Posted by Frankenrex (Post 10968284)
One up him and put a 20B in the 'Stang! :)
Heck, even NA would be interesting.

Haha as much as I'd love to, I would need a couple "one ups" in my bank account first :blush:

Frankenrex 02-07-12 08:15 AM

Don't we all? I know I do...

13brenova 02-11-12 07:37 PM

1 Attachment(s)
Great day at the track today! The guys from Hennessey got a kick out of a rotary powered muscle car. Not so much at first, but when they saw it had some satchel, they thought it was pretty cool.

Since this was the first time we had taken the car to the track, and have no experience racing rotaries, we started out super conservative. On the first pass, we launched at 5000 rpm and ran 15 psi. It bogged badly which resulted in a 12.8 sec. ET. As time went on we got more agressive and made our best run launching at 6500 rpm and running 21 psi of boost which resulted in an 11.0 ET @ 126 mph with a 1.50 sec 60' time. We were pretty happy with this, and most importantly, everything and everyone came home in one piece!!!! I'm working on cropping the videos and will hopefully have them done pretty soon.

The car carries about a foot of air under the front tire when it launches, and this is with 350 lb/in springs in the front. Can't even imagine what it would do with drag springs!

On the last run of the day, I upped the launch to 6750 rpm and did a healthy burnout. It launched freakin' hard! I think it yanked both tires this time because the car headed straight for the wall! Definitely some chassis mods and rear suspension work on the way!!! We figured we were pressing our luck and called it a day.

Had something interesting happen....on one of the runs, after I upped the boost a bit, the car cut out for a fraction of a second after the 2nd-3rd and 3rd-4th shift. I looked through the data logs and saw that the closed loop boost control would see the boost fall off during the no-lift shift and would crank up the boost solenoids duty cycle to compensate. When the spark would return after the shift, the boost would spike triggering boost cut. Haltech closed loop boost control works great during regular shifting, but not so much during no-lift. They need to have the wastegate hold it's duty cycle when the no-lift is active. I'm going to suggest it to them and see if they'll add it to the next firmware rev. So I switched to open loop.....problem solved.

We brought the old man's Z06 out, but it couldn't make a clean run on street tires and spun badly on the top of 1st and 2nd. So the jury is still out on which one is faster..............

Things to do before the next track session:

- I had the no-lift set for 350ms. After watching the in-car video, I realized this is way too long. I need something more like 250ms. That ought to add a little more mph on the top end.

- I tend to short shift 1st and 2nd. Just practice and removal of the gimp factor.

- Sort out the rear suspension and up the launch at 7000 rpm. The car twists too much on the launch. I'm thinking rear sway bar and changing the right rear spring from 150 lb/in to 170lb/inch or so. I know this thing has a 1.4 60' in it.

- More boost. We stopped at 21 psi, but I've run 23-24psi on the street. We just ran out of time to up it anymore.

- Lean it out.....maybe. When Steve Kahn did the initial tune, he had it at about 12.0 afr on my gauge. Since then, we added water/meth injection and richened up the tune to about 11.4. We're leaving quite a bit of power on the table......but we did make it home in one piece.

When we get these things sorted out..........I see 10s in it's future!!

Attachment 719990

13B-RX3 02-11-12 07:45 PM

Congrats man!!!! Get that video up here stat!!!!!!!

13brenova 02-11-12 07:58 PM


Originally Posted by "LILHEMI" (Post 8508736)
I cant wait for you to take that thing to the race track and have all the v8 guys laugh at you while you run 15s in this thing.

:fawk:

13B-RX3 02-11-12 07:59 PM

:lol::lol::lol::lol::lol::lol::lol::lol::lol::lol:

13brenova 02-11-12 08:36 PM

http://www.youtube.com/watch?v=AoDOzEeV2SY

http://www.youtube.com/watch?v=unDqFagtegQ

http://www.youtube.com/watch?v=CzU8Ov5pGdM

13B-RX3 02-11-12 08:53 PM

That fucker launched on the last pass!!!!

Rotor_Venom08 02-11-12 09:15 PM


Originally Posted by 13brenova (Post 10975727)
:fawk:

LOLLLLL :blush:

13B-RX3 02-11-12 09:23 PM

See what the piston guys have to say.

http://www.yellowbullet.com/forum/sh...d.php?t=449174

Narfle 02-12-12 04:59 AM

That's about the fastest 11 you can run!

sk8world 02-12-12 10:08 PM

congrats man!

Wildman923 02-14-12 04:49 PM

Awesome build :icon_tup:

prrex4ever 02-14-12 08:44 PM

Love it!

13brenova 02-15-12 08:07 PM

Took down the video links and replaced them with these.............better quality.

http://www.youtube.com/watch?v=EUhz2MjT1fE

http://www.youtube.com/watch?v=fOGbyjl8k-o

1973rx3 02-15-12 10:26 PM

Just plain ole amazing! Good job!

bad 83 02-16-12 09:09 AM

Wow. That thing needs some wheelie bars!!!!! Awsome. I'm glad to see how far this has come. Fine work sir :D

Grant M 02-16-12 10:57 AM

What diff ratio are you using?

13B-RX3 02-16-12 11:04 AM

Nick, i cant see the original video's anymore but it looked like you did not clear the waterbox before the burnout. It looked like there was still water on the tires when you rolled out after the burnout. You have to be careful about doing a burnout or scrubbing the tires while still in the water with a treaded tire. Treaded tires tend to sling a lot of water into the wheel well and it can drip back onto the tires. Roll trough the water and start the burnout on dry ground.

13brenova 02-16-12 09:33 PM


Originally Posted by 13B-RX3 (Post 10981898)
Nick, i cant see the original video's anymore but it looked like you did not clear the waterbox before the burnout. It looked like there was still water on the tires when you rolled out after the burnout. You have to be careful about doing a burnout or scrubbing the tires while still in the water with a treaded tire. Treaded tires tend to sling a lot of water into the wheel well and it can drip back onto the tires. Roll trough the water and start the burnout on dry ground.

I think you're right. Next time, I'm just going to drive through the waterbox instead of stopping to spin and wet the tires a bit first. My lack of racing experience showing through right there. The tires are honest-to-God slicks....no tread, but I still think you're right about the water.

Honestly, I was so concerned about finding the right launch RPM, hitting the no-lift shifts, easing into boost, EGTs, and why the closed loop was spiking, that I never even thought about shocks. The rear shocks were only set to 5 clicks firmness and the front to 0 clicks. If I would have upped the rear shocks to about 10 clicks, and the front to 4 clicks or so, the car would have settled down a bit on the launch a bit and been easier to control.

Lots of things could have been much better........but they could have been a lot worse too. I'm guessing 10.6 @ 131 at 25-26 psi with a 6750 rpm launch........after I get my shit together.


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