240z SCCA vintage race car, restoration

[AydinZ71]

Column drop works great. Just got to weld on an attachment tab and she is done. 

[rossman]

Looks great!

[tube80z]

On 8/5/2021 at 6:13 PM, JMortensen said:

Isn't the factory alternator 40A? Is the tractor one smaller, or internally regulated? Why not just use a good stock setup?

 

 

It's internally regulated and physically smaller, in case that's of any help.

[tube80z]

On 8/10/2021 at 12:51 PM, AydinZ71 said:

Cary, I will be pushing the data acquisition and analysis to a later phase of the build. I feel like I need to get out there and get some seat time before I can truly appreciate what metrics will mater most to me. That will save me some time to save up for a fancy new electronics package as well (leaning AIM). Important thing is to purchase/install the right sensors into the build now, so I can avoid new brackets/mechanical connections in the future (if possible). That way, adding electronics becomes a purely electrical exercise vs. re-work. 

 

I think you should at least invest in a GoPro that can provide data and use the RaceTechnology software (https://www.race-technology.com/us/gopro) if the budget allows.  Capturing data with video will help make you a better driver far more quickly than without.  It also would be useful if you wanted to use a virtual coach.  There are a lot of people doing this now and from what I've seen it can be super helpful.

 

I also can't stress enough how important it is to have a racing notebook.  You can use this to keep all your setup sheets, run sheets, etc. together, and plan out what setup changes to make.  I'm also a big proponent of every time the car runs it has a change on it and for the last run I check against the baseline.  This will show you if the track got better or worse and provide some additional context to any changes that may or may not have made improvements.  The way I figure is you're running the car anyway so why not learn from it.  

 

Sorry for going way off topic in your thread.  

 

Cary

[AydinZ71]

@tube80z hey thanks Cary! I really appreciate the feedback! No appologies necessary, as any feedback is appreciated. I will certainly look into the go-pro and racetechnology! 
 

@rossman thanks!! 
 

 

[AydinZ71]

Ok so I made a boo boo. My steering column got some grit in it and makes a light pepper-grinder sound when I turn the wheel. Like an idiot, I pulled the retaining clip on the steering-wheel side of the column. So apparently there is a spring in there that immediately shoved the shaft into the column and now I can’t get the retaining clip back on. Crap. Anyone know how I can pull the shaft out to get the retaining clip back on? 
 

 

[JMortensen]

I pulled one apart maybe 10 years ago. All I remember about it is that it's not a big deal at all. I had the spring out and all that, I think my purpose was to clean and grease the bearing. Take the column out of the car and figure it out. Just not that complicated.

[AydinZ71]

25 minutes ago, JMortensen said:

I pulled one apart maybe 10 years ago. All I remember about it is that it's not a big deal at all. I had the spring out and all that, I think my purpose was to clean and grease the bearing. Take the column out of the car and figure it out. Just not that complicated.

10-4. Maybe I need to shove something in the opposite direction down the shaft to release the spring load. Il figure it out  Just not familiar with the assembly. Il look for a cross section or something. 

[AydinZ71]

UPDATE:

 

- Firewall metal work is complete for pedal assembly

- Steering column drop-mount is complete and tested. 

 

Engine Ignition: I have decided to go with the open-source EDIS-6 crank-fire ignition system from Ford. My ATI pulley/damper is with the machine shop getting the trigger wheel mounted and balanced. Will buy the MegaJolt EDIS ignition module which will allow me to set advance etc. with a TPS, and map the ignition across all RPM's.

 

QUESTION: Anyone know of a good resource or book for learning more about fuel and ignition tuning principles?

 

EP runs SU carbs, so I will have 2X Air/fuel O2's and gauges (one per each carb) so I can monitory and adjust them before track days. I know ~14.7 is stoichiometric, but i have a feeling I should be targeting different A/F across the RPM band (13? 12?). Same with ignition, I need some guidance on what I should be targeting. I know the best approach is to Dyno tune the engine for max HP, but id like to get close in the meantime and modifying my SU needles can not be done on-the-fly. At $400 per session, I will be unlikely to budget for multiple sessions. 

[clarkspeed]

My 2 cents.  You will probably learn just as much on the Megasquirt site as any book will give you.  It is very extensive. I'm not sure you really need a TPS for ignition, most racers just run RPM (mechanical) advance. But I always liked adding some load advance because it does make things a little smoother on throttle transition and makes it "snappy" at throttle tip in.  I would think you generate plenty of vacuum with SU's so a MAP sensor may be better than TPS for load? I don't know.  I don't have any vacuum so I must use TPS for load. I run a curve similar to below with my EFI system.  Pretty standard stuff, 32 degrees all in a 2750.  I played with timing on the dyno and didn't get any real gains. More benefits playing with cam timing.  You can convert my tps numbers to a % if you want.  Should get you in ball park.

 

Theoretically 12.5:1 is air/fuel for most power.  I have always found 12.7-12.8 to work best and that is what I shoot for. Dial it in for full throttle at the dyno, but get a data logging O2 system so you can continue to fine tune it at events.  I gradually fine tune low rpm and part throttle stuff over time or if you feel a stumble somewhere.

 

Maybe you will get some better answers than mine.  May need to post in L6 forum.

[AydinZ71]

Thanks Clark! That is all very helpful  

 

MegaJolt (the EDIS timing module) suggested a TPS for “big cams”. They described the erratic vacuum off-throttle from a big cam as the reason. My 320 duration will probably be an issue with a MAP because of reversion at lower rpm’s. The timing advance I’m looking for is to maximize the off-throttle response when shifting. Otherwise everything will be optimized for WOT. 
 

I really need to get an O2 logger. Il look into one. 12:7 is something I will target and see how she wanders! 

[clarkspeed]

Yea, I could see 320 duration as giving some vacuum issues. Then again, take my TPS values, they should get you close. Much of the low RPM, Iow load stuff is just to get it cranked easy.

I recently purchased a 14point7 system to tie in with my data logger. I have not used it yet, but it was recommended to me buy a reputable tuner.  The Innovate stuff is good too, but as in previous posts, goes back to how much data you want to collect and what do you want to collect it with. 

Edited September 3, 2021 by clarkspeed

[AydinZ71]

Appreciate it friend! Need to take some days off work so I can finish the structural work. I will look into the innovate data logger. I have been spending like a drunk sailer, and the Stahl header I have on order will be almost another grand. Man… race cars are expensive! 

[clarkspeed]

8 hours ago, AydinZ71 said:

Appreciate it friend! Need to take some days off work so I can finish the structural work. I will look into the innovate data logger. I have been spending like a drunk sailer, and the Stahl header I have on order will be almost another grand. Man… race cars are expensive! 

Tell me about it. For my build I am trying to do all the work ahead of the spend. I only purchase parts that I need to weld around. My goal is to get to a completion state where I only need to final assemble and wire it up. I have this huge list of parts I will pull the trigger on as soon as I sell my other car. Most of that is shocks, wheels,  tires, and gauges.  But I am trying not to sell it so I can still race until this one is finished.  That cross over point is getting closer. I am still not sure what I am going to do with the motor yet, but I have a few options.

[AydinZ71]

I hear ya! Same… I got the steering column refinished and the Tilton pedal assembly in so I can weld the firewall, stiffen the mounting surface, and get the clearances right. 
 

I purchased most of the EDIS parts for the “megajolt” ignition. ATI dampener and trigger wheel are at the machine shop now getting balanced. Everyone is busy as hell so trying to get a head start.

 

Got the cam oiler on order from Greg’s dude. Going to take a big step and get all my electronic/analog gauges on order. I don’t have the funds for AIM (but I sure wish I did!). 
 

Plan is to run the 10:1 320 duration .500 lift head for now until I get more experience. Next step will be 12:1 w/race fuel.

 

Clear display of my ADHD, I’m already planning the next chassis. An all tube-frame Street/fun car. Plan is to buy a junker <73’ w/ a clean title. Use all the body panels and build a complete AL tube frame around it. Eyeing an K24 @ a modest 16 psi boost. Idea is to optimize weight/power with no specific interest in racing class. 
 

attached some pics of my recent progress on the EP car. Driver side rocker and dogleg are on. Next is clean-up and starting on the engine bay subframe 

[AydinZ71]

Missing sheet metal in wheels wells are done.  Used sheet to create webbing around the strut tower stiffening tube. 
 

Only chassis rust work left are my engine bay frame rails. Got a great deal on some 316SS tube, and the OD is identical to the OEM square tube ID. Now to think through how I’m going to attach it. 
 

other updates: 
 

- Megajolt parts are all in hand.

- Still waiting on my Stahl header. Should be done late Oct., then in to ceramic coating.

- Mishimoto radiator in hand

- acquiring gauges. Mostly looking for cost effective ones available used. Only interested in electric units. 

[Datz44]

@AydinZ71Nice work!! I admire the beautiful work. I began HPDE (2 events: Nelson and Mid-Ohio) this month with my daily (Elantra GT) and I'm thinking on a stock track car. Something to will eventually spank Porsche's on the straights with work.😉 The Elantra is doing that on corners 😇  I'm debating on putting the 240Z (blood, sweat and tears+love) on track or get a 280z (rust resto then track build with more track experience in it) + storage. I'm learning a lot from your blog/forum!

[AydinZ71]

@Datz44 thanks friend! I think you should decide one of the following courses:

 

1) race in an SCCA class w/ very very specific rules

2) race in a vintage league. Less competitive and the rules are really loose. 
3) build whatever you want, and just enjoy track days, time trials, etc. 

 

your decision on what car to build and how, will be very dependent on this decision. 
 

If going with #1, definitely go for the 240z. It is one of the most competitive weight/power potential in the production class. If going for #2, id buy a cheaper 280z chassis and lighten the heck out of it. If I was going for #3, I’d buy the various panels and build a tube-frame from scratch. The only component I have not found so far available aftermarket in fiberglass is the roof. Every other exterior panel is available. 
 

I think the ultimate track Z (just my opinion) is a full tube frame, with flat panels in either AL or fiberglass. I’d look at a Honda K24 engine w/ a small quick-spooling turbo. I would source forget aluminum hubs and control arms, make my own crossmembers and subframe. I bet you could get the weight down to 1700lbs, and still have 350+hp to play with. The problem is, it will not qualify for any class that I am aware of. If it does, it will likely be uncompetitive without some serious aerodynamic mods. 

[Datz44]

22 hours ago, AydinZ71 said:

@Datz44 thanks friend! I think you should decide one of the following courses:

 

1) race in an SCCA class w/ very very specific rules

2) race in a vintage league. Less competitive and the rules are really loose. 
3) build whatever you want, and just enjoy track days, time trials, etc. 

 

your decision on what car to build and how, will be very dependent on this decision. 
 

If going with #1, definitely go for the 240z. It is one of the most competitive weight/power potential in the production class. If going for #2, id buy a cheaper 280z chassis and lighten the heck out of it. If I was going for #3, I’d buy the various panels and build a tube-frame from scratch. The only component I have not found so far available aftermarket in fiberglass is the roof. Every other exterior panel is available. 
 

I think the ultimate track Z (just my opinion) is a full tube frame, with flat panels in either AL or fiberglass. I’d look at a Honda K24 engine w/ a small quick-spooling turbo. I would source forget aluminum hubs and control arms, make my own crossmembers and subframe. I bet you could get the weight down to 1700lbs, and still have 350+hp to play with. The problem is, it will not qualify for any class that I am aware of. If it does, it will likely be uncompetitive without some serious aerodynamic mods. 

 Thank you for the advice. I'll look up the rule book for each choice. 

[AydinZ71]

Latest updates. Replacing my rusted unibody frame stiffener w/ 316 SS tube. Will box-out the front, mount the rad for clearance, and replace the top crossmember next. 
 

Also finished my little project replacing my rusted cowl box with an engine vent out of the OEM cowl vents. Might not fly with the SCCA judges, but I can always block this off with a sheet of steel if I have to.