Project RX7 Race car - Progress so far!

[Jenn]

Glad I found this thread...Great pics and updates...The 7 looks clean, mean and ready for battle (2thumbs)...Are you currently racing in the TRAC series? Will you be participating in any other events and or series?

Let me know if you've got room for some mazdas247.com decal love...It would be great to have more rotary-heads on Mazda Forums...I really enjoy reading threads like this one...Thanks and keep the updates coming!

I always have room for Decals. lol PM me for my address and I'll slap a couple on there. lol

Yes, we're currently racing in the TRAC series. Next race is August 26th, then after that in September. Link is in my sig! I may try my hand at autocross with the car if I can find some RA1's to put on it. Slicks aren't great for that due to not heating up quickly lol. Also, I do a crap load of car shows with the car promoting the series.

Update:
Just got a box of stuff from Racing Beat that needs to be installed. Before the next race we will have installed:

-Racing Beat competition engine mounts
-RB modified Weber 51IDA (51mm downdraft carb, extra large throttle plates, custom machining, custom velocity stacks) with custom 48mm venturis and jetting by Nick at Rotary Reliability and Racing
-RB Aluminum intake manifold
-New exhaust gasket on header/pipe joint (we're currently burning our concrete floor when it revs up due to a leak)
-RB Decals (Yay for partial sponsorship!)

Since the last update we've also installed 3/8" fuel line all the way to the front, the holley blue electric fuel pump and a new fuel filter. The pump and filter were installed inside the car to be easily accessible, which led to us building an aluminum fire break over it with a hinged lid for fueling. Don't have an actual picture but it was based on this drawing:

 

[Jenn]

A couple pics from on the track:

 

[evilmonkeyMSP]

we need flame shooting pics

 

[Jenn]

Hah! Don't have any yet, but I'm sure a few will appear after the upcoming race weekend. lol RICH fuel mixture!! haha downshift BANG hahahaha

 

[chuyler1]

Get a sound clip too!!!!

 

[Jenn]

I'll try. lol

It's loud. hahaha

 

[evilmonkeyMSP]

well its a lawnmower, its supposed to be

 

[Jenn]

well its a lawnmower, its supposed to be

Heh, no THIS is a lawnmower!

(Just in case you're wondering, it's a Formula Renault at our second race weekend.)

 

[shane02pro5]

^ Awesome shot!!

 

[Jenn]

Update:

Went to put on the RB intake manifold on the weekend and it didn't quite fit (it hit along the bottom where the header flange is). Machined that down and now it fits like a glove.

Installed the Mazda Competition Engine Mounts as well on the weekend, but in the process of lifting the front of the engine a few inches, the hook of the engine lift somehow touched the alternator charge wire, and caused spark and a small electrical fire. Luckily, it just affected that one wire, and it should be an easy fix. What I am wondering is why that wire had any current to it when it's supposed to run through the master shut-off switch meant to kill all power to the whole car. I may have to rewire it when I take it apart to replace the wire. Lesson learned though, always unhook the battery cable even if you're not working on electrical stuff.

Last night we test fit the new carb on the car, and discovered we need another piece, so I called my Racing Beat guy and it's now being express shipped to me. Then I just need to move the throttle cable bracket and move the fuel regulator to allow the fuel line to reach the new carb. Hoping to have this all together by the end of the week. I'll take some pics when I get a chance.

 

[pHeeL tHiZ ViBe]

hey i think this car is awesome! two thumbs up on the find, and what you've done with it so far . it looks great, but i want to know how well it runs?!

 

[Jenn]

So we went to the track yesterday for testing, and the engine works REALLY well now! We wrapped the tach back around past 8,000rpm yesterday haha

Anyway, we only have one more issue that needs to be resolved. On the new manifold, there's no place for the vacuum line for the power brakes (goes to the brake booster) and so we're stuck with manual brakes at the moment. I've sent an email to Racing Beat to see what they suggest, and we may have to add a fitting for the vacuum like because I can't deal with manual brakes. lol You REALLY have to stomp on it to make it stop.

Just that, a little adjustment to the throttle cable, and something to fasten the velocity stacks on the carb, and we should be set for racing this upcoming weekend. Stay tuned!


Oh and Antoine, I haven't forgotten about getting back to you about the decals, I just haven't had a chance to measure a spot.

 

[urbanbiker]

Do you have a section on the manifold that willl have vacuum from more than one "cylinder"? I had dual side draft DCOE Webers on my Honda, so one barrel per cylinder, and I pulled vacuum from a single cylinder for the brake booster... it didn't feel the greatest. Inconsistant pedal feel because of the vacuum pulse.

I dont know how the manifold is designed exactley but you will want the steadiest vacum signal that you can get

Matt

PS Do you want my old spare parts for my DCOE Carbs? I don't know if you can use them but I've got some linkage parts as well as jets and such. Its a small assortment but it might be able to help you out.

 

[Jenn]

Do you have a section on the manifold that willl have vacuum from more than one "cylinder"? I had dual side draft DCOE Webers on my Honda, so one barrel per cylinder, and I pulled vacuum from a single cylinder for the brake booster... it didn't feel the greatest. Inconsistant pedal feel because of the vacuum pulse.

I dont know how the manifold is designed exactley but you will want the steadiest vacum signal that you can get

Matt

PS Do you want my old spare parts for my DCOE Carbs? I don't know if you can use them but I've got some linkage parts as well as jets and such. Its a small assortment but it might be able to help you out.

The only things that are the same as my new carb are the jets and emulsion tubes and our jetting is nutty (240 main, 110 airs !!!). Only thing I need for a DCOE at the moment is the top of the carb where the floats hook on. A little piece broke on mine, making it hard to be able to sell the old carb.

 

[Jenn]

So the manifold is now at the machine shop getting tapped for the fitting for the brake booster vacuum line. They said it'll be done by Friday, and we're going to the track Saturday for race weekend. Here's hoping it all works right!

Tonight we're gonna bleed the clutch I think. It was being weird last time I drove the car, and we have yet to do that this year.

 

[Lt. Dan]

myself and velocifero are the ones Maff is talking about in reguards to needing carb and ignition help.

Unfortunatly we are using a racing beat holley setup so i have a 600cfm Holly 4brl double pumper sitting here. I rly need to get the carb to a guy at the mazda dealership who has done it before.

As for the igntion: how are you running the ignition setup? we do have an electronic dizzy already but have no plans on running the wiring harness and such just to reduce weight and mess.

And those HP numbers are rly exciting. Its more than i was expecting to get out of the engine we are running. Its got a j-bridge port, 91 rotors, mazdatrix carbon seals and the holly 4brl racing beat kit among the other stuff. BTW what are you reving your engine to?

Sorry that I'm only seeing this post now... If you are road racing the above setup, don't even bother putting any more money into the carb. Because of the way the carb sits on the manifold, in High-G corners, you'll get fuel sloshing out of the vent tubes, and into the carb... Major bogging... I tried running the bowl levels as low as possible, center hung bowls... Even fabbed up an "offroad" style vent-tube... No dice.... Sell that carb setup, and buy a sidedraft....

 

[Jenn]

Well, we raced on the weekend. The car seemed to work well, just getting a feel for it on the track now and finding the limits. Doing practice and lapping on Wednesday night.

Power brakes are working now, new carb seems to be fine (Weber 51IDA Downdraft), just gonna play with jetting right now.

 

[Jenn]

From this past weekend:

Me and my better half after I just got out of the car after my race:

Weekend went well overall. Car is still shiny, I wasn't last. lol Still working out the kinks, and now we have a plan over the winter.

Also, took the car to a slalom on an airstrip.

There is video of me racing. I'll upload it when I get a minute.

 

[Jenn]

Well with one season down, the project now begins again to prepare it for next season.

So far on the list, we have:

Custom gauge package
Racing Beat Oil Pressure/Temp sender adapter
Racing Beat True Dual Road Racing Exhaust
Hood scoop to help the carb breathe a little better (cowl induction style)
Rebuild transmission to fix 3rd gear synchro
New final drive gearing (looking at maybe 512 gears in the rear end)

And I'm sure the list will grow longer...I'll keep everyone posted!

 

[Antoine]

Great pics Jenn! (thumb) Glad to see the 7 performing well.

Be sure to keep the updates with pics coming of your winter progress!

Ps...Did you ever receive decals from Rickman?