RX7 Hillclimber Build Thread

Ouch!  Can't give you anything pretty.

https://www.facebook.com/plugins/video.php?href=https%3A%2F%2Fwww.facebook.com%2Ffacebook%2Fvideos%2F10216922292757592%2F&width=500&show_text=false&height=281

This forum sure does make you work to post things

DaveEstey said:

This forum sure does make you work to post things

Yes!  How did you get a video to post in a large format?  Yesterday I couldn't get a video to post at all and previous to that it would only appear in a tiny window.  I was just complaining that how videos are done keeps changing and keeps being buggy and weird.

I used facebook video option

In reply to DaveEstey :

Figures, I've been trying to post a youtube video for two days with no luck.

Last weekend we took the LeMons RX7 to Thompson Speedway to try out the BRAND NEW EFFING ENGINE.Why would I refer to it like that? Because it started pressurizing the coolant system almost immediately.

We nursed the car through Saturday with long breaks to cool down and refill the coolant, which didn't do much for our standing. When we were on course though, we ate cars up in the corners thanks to superior handling and braking. We certainly didn't have much power though, which was evident on the straight.

We ran one stint Sunday morning with dropping pace and decided to pull off rather than completely wreck the engine for no reason.

So long story short, we've had two "new" engines built and they've both been duds. No longer going to that fella and we're going to move to a more conventional powerplant.

Stay tuned for GM 3800 swap shenanigans.

I'll get another shot at Thompson on the 25th when I instruct with SCDA, which means I can bring the hillclimb car along for some action.

Reckon some effing new engines are newer than others.  Sorry for the trials/tribulations and $$.  

3800 is a heavy lump....any thoughts of using something lighter?

We put a 3400 in our fc. If I had to do it again, I'd probably go 3500. 

3800 would be fun too!

In reply to MichaelYount :

Three Pedal Mafia weighs in at 2,4XXlbs with the 3800 swap, which I think is plenty light. Newer engines come with more computer things to go wrong or be fussy, which is unattractive.

I already have a line on a Series III 3800 S/C full running car for $500

The SC engines are different than the RWD versions.  There is much research that I did to see if this was possible for our car.  Unfortunately, I forgot most of it because we went with the 3400.  The intake is definitely a point that will need to be looked into.  Also, check into how the starter mounts.  I cant remember if there is a place to mount a starter if using a FWD based 3800 with the RWD trans.

The transmissions hold up well as long as you get the clutch release correct (if using a 97+ F body V6 trans).  Thats what we run and they work pretty well.

You will pretty much just use 4th and 5th gear with that engine and trans combo.  It works well for us.

LeMons lows pushed aside, I'm prepping the hillclimb car for its first "For reals" track day. I'm instructing with SCDA at Thompson this coming Saturday, which affords me some time on track while it's still very fresh in my head.

The To-Do list isn't too daunting
1: New tail light bulbs (My LEDs didn't like Ascutney apparently)
2: Massive NACA duct to force fresh air to the rads
3: Hood vents
4: Remove a few dents where possible
5: Install 275lb rear springs
6: Bleed brakes
7: ?????
8: Profit


 

When I bought the car from a fellow GRMer in 2012, it didn't have working brake lights. Since then - it also hasn't had working brake lights.

A pressure switch, some 921 sockets and LED bulbs and BAM


Check one off the list.

The exhaust will be hung nicer as well. I replaced all the rubber mounts with Poly and now she's Gutten Tight

Giant NACA is next.

To facilitate construction I printed some 1" isoceles triangles out of carbon fiber reinforced nylon.

Next up, some head scratching and maths. Then cutting.



Not worried about "ruining" this carbon hatch as it has a lot of surface imperfections from my vacuum pump failing while it was curing. If this all works well I'll make a fresh hatch.

Made some fresh carbon fiber to form the sides and screwed them into place. Once this is all done I'll add reinforcing carbon layers to add more strength.

The carbon I made for the floor of the duct is still curing, but will be installed tonight.

No pictures, but I installed 1/4 lexan as the end plate where the ducts will attach.

As you can see my carbon surface finish is much improved with time and experience.

I love spring changes in this car. 2 wrenches and 20 minutes. Took 50lbs out of the rear rates to see if I can get more compliance. 

Fresh carbon plate is done for the floor of the NACA duct. Really have the surface finish dialed in lately.

The Crocodile-Dundee's-Knife of NACA ducts.  More like a NACA tunnel.   Daddy likes.  Nice.

Inspriration

Those Quattros had so much downforce, you couldn't get 'em off the ground with a lift.

Here you can plainly see the improvements in process  over the past 2 years. The hatch was my first big carbon project and my vacuum pump died. Womp. Didn't feel so bad cutting it up though!

Duct looks great! Are the screws temporary?

Screws are  for testing purposes. If this works well I'll make a new one-piece duct. As is she's quite rugged thanks in no small part to the 3d printed triangles that the screws anchor into

So did the NACA duct work?! Kinda. The 10" duct hose I had wasn't going to work, so I had to get some 6", which of course flows WAY less air. Still, I didn't have heat issues until my driver's side fan stopped due to a connector failing.

The car was still handling way too stiff even with the new springs, but I have that dialed out now. Taking it to a big autocross this weekend to test it.

Sidenote - time to think about a paint job refresh.  The roll into the woods didn't help things...