240z SCCA vintage race car, restoration

[tube80z]

On 7/29/2023 at 10:05 AM, AydinZ71 said:

 I bought some tri-gas for the mig and made a jig for back-purging. If anyone else’s is attempting this, keep this in mind: you will go through helium tri-gas FAST. Be stingy with the back-purge. 

Nice work Aydin!  

 

Here's my trick when it comes to back purging stainless exhaust tubing.  I use a pig.  Maybe that's not the right term but it's a device that you can run down the tubing connected to a cable/hose so that you only purge a few inches (8-10) near your weld.  You're probably thinking this is some high dollar piece of equipment.  It's not, it's a water balloon (more than 1) connected to the end of an air hose I put through the exhaust.  I use a valve to inflate/deflate on the other end.  When you need to weld the next bit of tubing you pull out enough hose, keeping track of how much you need to clear the weld area.  Sometimes you need to use foil to protect the "pig" from sparks or sharp edges.  

 

Maybe this will work for you maybe, maybe not.  I'm just a huge cheap ass who hates wasting expensive gas.  The last time I filled my argon was 2016 and I complained about the price then.  I just checked how much it costs now and almost broke my office chair from falling over.  

[tube80z]

On 7/29/2023 at 10:19 AM, calZ said:

Haltech is a pretty good option with almost Motec features without the Motec price. 

 

Also check out the MaxxECU range.  Andy Whittle has many nice things to say about them.  They have a lot of inputs/outputs that can be configured any way you want.  Andy is the MLVHD facebook admin and has been dealing with club racer tunes and hardware for years.  I like that he's always looking for deals and using OEM parts for sensors rather than the $$$ branded versions.

 

Cary

[AydinZ71]

@tube80z thanks Cary! I will look into MAXXECU! My nearest experience with EFI was the SDS system I have in the turbo street S30 I built 20 years ago. Now that I am much more confident on the wiring side (partly from engineering background, partly from the wiring fundamentals course on HP academy) i feel comfortable tackling just about any kind of sensor/actuator wiring not requiring a scope. In that way, I'm looking forward to a more open-ended ECU with more I/O so i can get more creative short of utilizing CAN. The 3.1L is definitely the least compromised engine I have built, so I want to build-in safety interlocks to kill the engine when necessary. 
 

100% clear on the “PIG” 😂 I commissioned the first natural gas pipeline in Jamaica (probably unqualified at that time), and learned more about pigs than I care to remember haha. What you propose is novel and makes absolute sense. Wonder why I didn’t think of it! The nice things about Tri-gas is since it’s mostly helium, you don’t need all the volume changes of a heavier inert gas just to get started. It kind of floods the top of the 3” tube, so you can start welding pretty shortly after you start the purge and still not seeing any signs of sugaring. Granted, you have to rotate the tube and keep welding from above, but I would be doing that anyways.

 

I gotta say, MIG welding stainless surpassed my expectations. I would argue it welds even better with tri-gas and 308L, than my regular mild steel wire and substrate w/ C25 gas. I blame that on the unavoidable flash corrosion and contamination Mild steel is susceptible to. 
 

one day I will migrate to TIG. I just don’t have the justification at the moment, since the exhaust is likely the last of my welding on this car. 

[clarkspeed]

Believe it or not, I am still running a SDS on mine. Plans to upgrade but have not justified it yet. Lots of good systems out there now. I've also heard good things about the Maxx. Haltech has been a solid product for many years. Troy Ermish recently posted he dropped Electromotive because of lousy support. I've tuned Mega's and they are solid too. Speedduino looks really neat for a simple system. Really tough to decide based on features vs. price. 

 

I think the higher level stuff gets deeper into traction control, wheel speed sensors, trans control, ABS, telemetry, and other motorsport needs. Top of the line is a Bosch. Most of the pro production race cars run them. I looked into their features 1 time and thought I will never use any of that!

 

Luckily any system that is good for the street is probably way more than you need for a 50 year old race car.

 

https://www.bosch-motorsport.com/content/downloads/Raceparts/en-GB/109903243.html

 

 

 

 

Edited August 2, 2023 by clarkspeed

[Ben280]

Looking good!

 

When choosing an ECU, I would ask your tuner what they prefer and buy that. Make sure it is compatible with all your bits and bobs. Haltech for example is notorious for keeping their CAN stuff difficult to access, similar to AIM. Tuners can work on just about anything, but what they can do and what they like to do are often different. 

 

I saved my megasquirt for the V8 conversion, but I would have been better off buying a Link or a Haltech, purefly from an ease of tuning perspective. Megasquirt idle control is finnikey at best! 

[AydinZ71]

On 8/2/2023 at 6:33 AM, Ben280 said:

Looking good!

 

When choosing an ECU, I would ask your tuner what they prefer and buy that. Make sure it is compatible with all your bits and bobs. Haltech for example is notorious for keeping their CAN stuff difficult to access, similar to AIM. Tuners can work on just about anything, but what they can do and what they like to do are often different. 

 

I saved my megasquirt for the V8 conversion, but I would have been better off buying a Link or a Haltech, purefly from an ease of tuning perspective. Megasquirt idle control is finnikey at best! 

Thanks Ben! yeah I’m really intrigued by Haltech’s dynamic learning feature. Apparently it monitors throttle, idle, etc and AF to long-term trim the fuel settings. Obviously won’t tune for WOT torque, but nothing will replace a dyno. I also like how much I/O you get for a $1300 ECU. I feel the need to include a knock feedback for ignition retarding. The head work on the N42 landed me around 10.5:1 on the 3.1L, so I think I will be knock limited vs. torque limited on ignition timing. Willow Springs is in the desert and 2500’ and decent so knock will definitely be a risk that will be hard to mirror on the dyno.  
 

if there is too much advance left on the table, I might take it to my local shop and have the head shaved to 12:1 for 100 octane. Got a spot near me for $11/gal on a pump which is rather convenient. I have the Kameari chain tensioner so I won’t need to shim my towers more or thicken my lash. 
 

I don’t have a tuner yet, but being in the LA area I kind of have my pick to choose from. I should call Erik’s racing and see what his preference is. He is obviously a legend, and has a flat $500 fee to tune from a base map. 
 

I’m looking forward to eventually using CAN and a digital HUD, but I’m appreciative of the opportunity to take a break from big spending 😂 Need to get some seat time before I can appreciate all there is to gain from data. I’m literally a novice driver 🤦🏽‍♂️

 

 

[AydinZ71]

On 8/1/2023 at 5:03 PM, clarkspeed said:

Believe it or not, I am still running a SDS on mine. Plans to upgrade but have not justified it yet. Lots of good systems out there now. I've also heard good things about the Maxx. Haltech has been a solid product for many years. Troy Ermish recently posted he dropped Electromotive because of lousy support. I've tuned Mega's and they are solid too. Speedduino looks really neat for a simple system. Really tough to decide based on features vs. price. 

 

I think the higher level stuff gets deeper into traction control, wheel speed sensors, trans control, ABS, telemetry, and other motorsport needs. Top of the line is a Bosch. Most of the pro production race cars run them. I looked into their features 1 time and thought I will never use any of that!

 

Luckily any system that is good for the street is probably way more than you need for a 50 year old race car.

 

https://www.bosch-motorsport.com/content/downloads/Raceparts/en-GB/109903243.html

 

 

 

 

 

Absolutely agree Clark! Came to the same conclusions. Honestly, I don’t want to run closed loop traction control even if the sensors were free. It’s a vintage race car after-all, and the “fun” is precisely in the purely mechanical feel and simplicity. Series 1 race car is the equivalent of a cable driven acrobatic hi-plane 😂, and it’s still a thing! 
 

I was pondering pulling my SDS from the turbo street car but then it won’t be running… my version unfortunately still requires the dizzy And they wanted $500 to upgrade the board. Hmmmm… as a type this it may be worth doing when I turn my attention to the street car. 
 

I will take a look at Maxx before I pull the trigger on Haltech. 
 

many particular sensor feedback you see a need for other than TPS, MAP, coolant temp, air temp, AF, and knock? 

[clarkspeed]

A lot depends on your induction system. I have 48mm ITBs with a short manifold. There is not enough vacuum to do anything with so no MAP for me. If you are using a 1 into 6 manifold or a stock based manifold, definitely use it. And most of the race guys I know avoid knock sensors. Maybe they are better now but in the past false vibrations would cause them to reduce timing and power. Street car on the hairy edge may be needed.

 

I can't speak for the closed loop tuning stuff. I don't know anyone who has used it to tune a true road or drag race car. 

 

I usually tune WOT fuel curves on a dyno. If really stumbling off throttle I might to a 1/2 throttle run. Then fine tune part throttle and throttle tip in based on data collected while driving. 

 

Don't think I would spend any money upgrading an SDS. That would not be practical. This thread got me looking at the Speedduino again. I understand sensors, wiring, and Tuner Studio so much better now.

Edited August 10, 2023 by clarkspeed

[AydinZ71]

@clarkspeed thanks for all the feedback Clark. I have the Jenvey ITB’s, so 50mm taper down to port-matched head. Just got my head back from MR. Yoes. Sounds like the MAP will be less effective to tune with than just a TPS. My cam is 256 @ 0.05”, 0.565 can lift, so I doubt I will have consistent vac anywhere near idle. Main goal is to tune WOT to torque, then just target a AF everywhere else.

 

I also hear some negative things about the knock sensors. My main anxiety is, I have never reliable been able to catch it in my ear at WOT in the past. I blew a few turbo motors as a result. I guess it couldn’t hurt if all I did to start was output a small light until I have confidence it works right. 
 

thanks for the feedback on the SDS. 

[clarkspeed]

50mm ITB's! That will be an on/off switch, but I personally think will make the power. Forget the MAP. 

 

Turbos are different. On a NA motor you can kind of sneak up on knock. You will hear and feel it with any muffler at all. Probably without. If unsure you can start with octane boost on top of premium and then back it out. I hate retarding timing on an NA motor.

[AydinZ71]

20 hours ago, clarkspeed said:

50mm ITB's! That will be an on/off switch, but I personally think will make the power. Forget the MAP. 

 

Turbos are different. On a NA motor you can kind of sneak up on knock. You will hear and feel it with any muffler at all. Probably without. If unsure you can start with octane boost on top of premium and then back it out. I hate retarding timing on an NA motor.

 

Me too! We are on the same page. I bought the ITB's over a year ago. At the time, I didn't recall if they had another L-series option other than 50mm. Agreed, its going to be a tight throttle margin. Should pair nice with the Stahl header with the 41mm primaries. The collector I have necks-down to 2-5/8" before expanding to 3" over a 3" transition. According to Burns Stainless, that will help broaden the torque band a bit lower than just a straight 3", without adding a noticeable drop in high end. 

 

Speaking of which, I welded the collector to the header once I confirmed I can install it in one-piece. Shipped it off to Swain two weeks ago. They are claiming a 10-week lead time so getting to work on the rest of the systems.   

[tube80z]

19 minutes ago, AydinZ71 said:

 

I bought the ITB's over a year ago. At the time, I didn't recall if they had another L-series option other than 50mm. Agreed, its going to be a tight throttle margin. Should pair nice with the Stahl header with the 41mm primaries.

 

One thing you can try to make the ITBs more drivable is to create a progressive throttle cam so the throttle moves a lot less on the initial pedal movement.  I had a car with light-switch SUs and this helped add some drivability to the car.

 

Cary

[AydinZ71]

3 hours ago, tube80z said:

 

One thing you can try to make the ITBs more drivable is to create a progressive throttle cam so the throttle moves a lot less on the initial pedal movement.  I had a car with light-switch SUs and this helped add some drivability to the car.

 

Cary

thats a neat ideal! Il do some research. I ditched the linkages for a lokar cable so il need to fabricate one anyways. 

[clarkspeed]

7 hours ago, tube80z said:

 

One thing you can try to make the ITBs more drivable is to create a progressive throttle cam so the throttle moves a lot less on the initial pedal movement.  I had a car with light-switch SUs and this helped add some drivability to the car.

 

Cary

That is a great idea.  That would make 50's work on street fairy well.

 

In my opinion only without direct supporting data, think a large TB with a highly ported intake on EFI makes max hp from a NA L6.  My intake is ported so much I broke through the walls. I don't think I measured over 6 (in. Mercury?) Vacuum with throttle cracked open. I also highly suggest a VERY OPEN filtration system. Can't be too large. What are you planning upstream of the Jenvey's? I saw Troy Ermish put a 5" diameter cold air on a race 4 cylinder.

 

 

Edited August 14, 2023 by clarkspeed

[tube80z]

On 8/13/2023 at 4:49 PM, AydinZ71 said:

thats a neat ideal! Il do some research. I ditched the linkages for a lokar cable so il need to fabricate one anyways. 

 

Almost all the new throttlebodies have them as a cam and you can either borrow one or make something similar.  If you wanted to do it so that the linkage looked stock you probably could hide this under the dash or put the same on the firewall for the cable from the pedal would wrap onto.  

 

I think you could make different options to fine tune the response to where it works best for you.  I stole the idea from John DeArman (sp?) who used to have a Z car technical magazine.  And was a prolific poster on the old. alt.hotrod Usenet news channel.

 

Cary

[clarkspeed]

Or if you really want to be sophisticated, buy a throttle by wire pedal. I see many of the EFi systems support it now.  Program your own linear ramp.

 

[AydinZ71]

On 8/14/2023 at 6:34 PM, tube80z said:

 

Almost all the new throttlebodies have them as a cam and you can either borrow one or make something similar.  If you wanted to do it so that the linkage looked stock you probably could hide this under the dash or put the same on the firewall for the cable from the pedal would wrap onto.  

 

I think you could make different options to fine tune the response to where it works best for you.  I stole the idea from John DeArman (sp?) who used to have a Z car technical magazine.  And was a prolific poster on the old. alt.hotrod Usenet news channel.

 

Cary

 

Thanks Cary. I need to unbox my Jenvey TB's again and take a look at what they came with. Maybe they already took this into consideration! I just got them back from Yoes a few weeks ago, along with the N42 he completed for me (matched to manifold). Either way, it sounds like a great idea. 

Usenet! that really goes back! I started on the Z31 forum when i bought my first car (an 85' black NA) in 20' There was even a chat room on IRC if I recall correctly. man...things have changed. It feel like overall the trend has moved away from technical prowess and performance to more of an aesthetic vibe. I may be projecting. 

 

@clarkspeed yep, Haltech supports it now. I just assumed the added weight of a throttle actuator and another potential electro-mechanical failure point would make it a "bad" idea for a race car but really I have zero experience and no idea. I already completed the pedal and firewall adaptation for the Lokar cable, so now i just need to complete the hookup to the end effector. I'm excited to see someone try it!

 

 

Edited August 18, 2023 by AydinZ71

[DuffyMahoney]

I have a few progressive cams left to sell, if anyone is looking.

[AydinZ71]

All hydraulic lines complete. Accusump installed. Fuel system 80%. Beginning oil cooler plumbing and front suspension installation. 3.1L is nearly complete and contemplating installing it with SU’s until my budget can accommodate injectors, ECU, etc. 

[HowlerMonkey]

I used a cable and a cruise control cable cam from a early 1990s nissan throttle body (probably 1992 stanza).

 

When I took it apart, i noticed a plastic bushing for it to ride on that looked like it was the same size of the throttle shaft for L28s.  

It does fit and I simply worked out the proper clocking and drilled it through for a bolt.    

It's not progresive so massive or multiple throttle bodies might feel touchy on a N/A car.

Edited August 29, 2023 by HowlerMonkey