Dynoed my L24 at Zcon

[Tony D]

We don't have an emoticon to express a guy in a trenchcoat hiding (nay, suspiciously and conspicuoulsy concealing) something.

 

That is about how I feel about that thing!

 

Come to think of it... it's 'packed in' up top in the yellow car. Man, I got so much crap I've packed away in storage...

 

I should look through my documents, his original invoice may have that information on it. But finding time to get to do that may be tricky. We actually met at one of the early MSA events, and his...er... "Manner" towards someone asking questions drew me to him. After that the price came down considerably.

 

Anybody who dealt with Don will know what I'm referring to! That I was drawn to it out of curiosity is probably indicative of my downfall at another site...

[z-ya]

Anyone use one of these with and MSD6AL?

 

http://www.msdignition.com/product.aspx?id=6997&terms=8980

 

It is a fixed curve, so you need to lock the advance in your distributor. You can also set a step retard.

 

 

 

Or this one that is adjustable:

 

http://www.msdignition.com/product.aspx?id=6929&terms=8680

 

It's probably not all that useful since your really not changing the curve.

Edited September 2, 2010 by z-ya

[madkaw]

Looks like that MSD only changes the final amount of advance, which is helpful, but not what I'm looking to do. I think better results can be obtained by modifying the Nissan dizzy, but not as easy as turning a knob. Getting that vacuum advance to work with a power curve is the challenge. My car is awesome at 21 intial and 36 total, but I can't use the vacuum advance for economy.

 

My next dyno run will be at the quarter mile at indianapolis, and I plan to run the car at the same timing setting as I did at zcon, then I am going to go for a pure power run with the vacuum advance plugged. Then I will work for something in between. I am kind of anxious to see the difference in the first two runs. My butt dyno says it will be considerable. I do have to keep in mind that i made a BIG float adjustment since the dyno run and I have gained at top-end for that effort. This is the most workable approach since Tony is hiding his top-secret dizzy somewhere is his toybox.

[z-ya]

Looks like that MSD only changes the final amount of advance, which is helpful, but not what I'm looking to do. I think better results can be obtained by modifying the Nissan dizzy, but not as easy as turning a knob. Getting that vacuum advance to work with a power curve is the challenge. My car is awesome at 21 intial and 36 total, but I can't use the vacuum advance for economy.

 

My next dyno run will be at the quarter mile at indianapolis, and I plan to run the car at the same timing setting as I did at zcon, then I am going to go for a pure power run with the vacuum advance plugged. Then I will work for something in between. I am kind of anxious to see the difference in the first two runs. My butt dyno says it will be considerable. I do have to keep in mind that i made a BIG float adjustment since the dyno run and I have gained at top-end for that effort. This is the most workable approach since Tony is hiding his top-secret dizzy somewhere is his toybox.

 

I think we talked at ZCON. I was one of the organizers. I had my orange 240Z there with the RB25DE.

 

The one I posted previous does change the timing curve, but it is fixed and needs a regular MSD box to fire a coil.

 

http://www.msdignition.com/Products/Ignitions/6530_-_MSD_Digital_Programmable_6AL-2.aspx

 

This on will let program the timing curve and it has a CD ignition built in.

 

 

Pete

[Noddle]

I think we talked at ZCON. I was one of the organizers. I had my orange 240Z there with the RB25DE.

 

The one I posted previous does change the timing curve, but it is fixed and needs a regular MSD box to fire a coil.

 

http://www.msdigniti...able_6AL-2.aspx

 

This on will let program the timing curve and it has a CD ignition built in.

 

 

Pete

 

for the price USD$ 410.00, you could buy a MS II unit and use spark only..

[Lazeum]

for the price USD$ 410.00,  you could buy a MS II unit and use spark only..

 

...or you can get the megajolt jr. kit for half the price + EDIS (80$)  This is one of my project in the future.

 

 

[z-ya]

Yup, know that (I run MSII/EDIS on my road racer). Thought he was interested in an off the shelf plug and play system. The other nice thing about the MSDs is that they can go in the engine compartment. The price is not bad considering that an L6 Mallory Unilight distributor with adjustable advance is more money. It's got a warrant too, which MS doesn't.

 

You can get them for $350 new on Ebay BTW.

Edited September 5, 2010 by z-ya

[madkaw]

Well I've tried to set the timing back to 10 btdc and keeping the vacuum advance, but I still get detonation at the vacuum and mechanical overlap point-around 2800rpm. Though it doesn't last that long going thru the gears, and it is only prevelant at a slow acceleration rate, I'm pulling the plug on the vacuum advance until I get something better.

 

one big reason is that I smelled coolant today inside my car, but couldn't find any source for the smell. Wasn't using the heat either. Looked around my heater core and everything looked dry. So paranoia set in--BLOWN HG. No white smoke, no visible leaks outside the engine, plugs looked alright. I took the cap of the radiator and started the car and saw some bubbles, but I think the thermostat just opened so maybe the rush of coolant caused the bubbles???? I just went back out there again after the motor cooled and simulated the same thing and bubbles right after the thermostat opened, but couldn't see anymore after that. Don't have the capabilty or time to do a leakdown right now-anything else I should check? Motor seems to run pretty smoothly though I have been messing with mixtures on the SU so it wasn't perfect.

 

I'm kind of dislexic(and a bad speller) when it comes to certain things, but now that the weather has turned cooler and dryer the mixture probably leaned out right? So if I leaned out the SU's on top of that, have I gone to lean and would that enhance detonation? I'm gonna research this right now so don't flame me

 

I want to take the car to the dragstrip this coming tuesday, but want to make sure there isn't anything wrong with the motor first.

[z-ya]

Well I've tried to set the timing back to 10 btdc and keeping the vacuum advance, but I still get detonation at the vacuum and mechanical overlap point-around 2800rpm. Though it doesn't last that long going thru the gears, and it is only prevelant at a slow acceleration rate, I'm pulling the plug on the vacuum advance until I get something better.

 

one big reason is that I smelled coolant today inside my car, but couldn't find any source for the smell. Wasn't using the heat either. Looked around my heater core and everything looked dry. So paranoia set in--BLOWN HG. No white smoke, no visible leaks outside the engine, plugs looked alright. I took the cap of the radiator and started the car and saw some bubbles, but I think the thermostat just opened so maybe the rush of coolant caused the bubbles???? I just went back out there again after the motor cooled and simulated the same thing and bubbles right after the thermostat opened, but couldn't see anymore after that. Don't have the capabilty or time to do a leakdown right now-anything else I should check? Motor seems to run pretty smoothly though I have been messing with mixtures on the SU so it wasn't perfect.

 

I'm kind of dislexic(and a bad speller) when it comes to certain things, but now that the weather has turned cooler and dryer the mixture probably leaned out right? So if I leaned out the SU's on top of that, have I gone to lean and would that enhance detonation? I'm gonna research this right now so don't flame me

 

I want to take the car to the dragstrip this coming tuesday, but want to make sure there isn't anything wrong with the motor first.

 

I would seriously consider one of these.

 

http://www.msdignition.com/Products/Ignitions/6530_-_MSD_Digital_Programmable_6AL-2.aspx

 

Jegs has them for $350. I plan one using one on a vintage racer soon. Lock down your distributor and program your timing curve exactly the way you want it. If you are going to the track this week, just put a few gallons of race gas in for a little insurance. That should cure any detonation problems.

[madkaw]

Well a totally disappointing trip to the dragstrip. Though the car held together great, my times sucked, The best i could muster was a 15.6, I have a lot of time and money in this car for 15.6. I'm hoping the triple Mikunis will wake up this motor. I will be getting a wideband shortly to verify what I think is a lean top-end.

[Tony D]

It won't help at all for my comment that at the San Antonio Z-Con my stock Fairlady Z 2+2 ran consistent 15.50's (26 passes that night)...

 

Don't swear at me like the guy with the matching coupe did. Best he could do was 16.45 all night long.

 

My burnout box display made it into J's Tipo in Japan...

 

Even stock, there is stock and there is optimized. Too many times people think there is HP to be had simply by bolting on things. I had Triple Webers on that same car, with a header, and blah blah... And it spun the dyno to the tune of 84 RWHP. After putting it all back 'EFI STOCK' I was running 147 HP and consistent 15.50's with a best time of 15.30!

 

Technology is not necessarily the answer, but proper setup of the components so they work well together is critical. Bolting on stuff rarely helps.

[madkaw]

Yeh, I realize that, that is why I am anxious to get a wideband on this car and stop guessing as to what I'm doing. I didn't just bolt on parts---well I did-but I do realize it's about tuning them all together. The car seemed lethargic revving out in 3rd gear. It was like I was watching the tach in slow-mo. Somethings a miss there, so I need to know what's going on----back to the O2 sensor.

[Tony D]

flywheel weight? rear gear ratio?

 

There is far more to perception of acceleration than horsepower and torque.

 

I have been in some very high horsepower cars that didn't feel fast at all.

 

Hell, my Fairlady felt fast as hell with the triples and headers, and felt really tamed down and docile with the stock EFI on it. But it was almost 2X the horsepower in the stock condition, versus modified.

 

Butt dyno was overruled by actual dyno, g-tech, and those dragstrip passes!

[Xnke]

I have a similar thing going on with my Z now...I haven't worked on the tune much after getting it smoothly drivable, been working on paint.

 

From 900RPM idle, it's an easy, smooth ride to 2000RPM...then you feel the car coming up behind you, starting to press you into the seat suddenly at 2500...then it just GOES..the tach flies around to 6.8K and the rev-limiter hits, just like if you had shifted to neutral. But from 900 to 2500 RPM, it's not that it bogs, it just "feels" docile, compared with the hit of the (small by many standards) cam.

 

I want to move that 2500RPM point down some, I think, but in this case, it's cam timing, then ignition timing. Once you have the wideband in there and can get the fuel dialed in, you'll want to adjust the ignition timing, then you'll see you're running lean in spots again. At least, that's how my engine has behaved.

[madkaw]

Well the wide band is installed-what an eye opener.

I can't explain all the info on the dyno sheet, but there are a few answers from the wideband.

The richness was from the front SU being way off on the mixture setting. When I was doing my adjusting of the mixture nut, i wasn't getting the nut bottomed out from the start because the nut was hitting on a clamp on the backing plate of the air breather. So instead of starting out at zero I was stsrting out around a turn and half. The rear carb was running very lean, so maybe the two mixtures together was rich, but not enough to produce smoke-as implied. I discovere this after zcon, but before I hooked up my wideband.

 

Infact, when I went to readjust here recently, I realized that i hadn't adjusted the air mixture screw on the linkage-so at 2000 rpm the front carb was pulling air and the rear was almost dead. It amazing that the car ran as good as it did for 3000 miles last year. Maybe that's why my MPG was so good to ZCON at about 28mpg. This may also be the reason the AFR's dropped way lean above 5100 as shown on the graph.

 

So now I start looking at my AFR numbers according to my wideband. At the present time I have dual exhausts with a bung on each bank. The wideband is hooked up to the front bank. In my dislexic mind the numbers look good-17.5 at cruise, until someone points out my error. So I went from way rich on the front SU before discovering the mixture issue, to running lean after adjustment according to my wideband. Are you confuse yet-I am!

 

So anyway, I have got the numbers on the front carb where they should be, running around 14.5 at cruise. Both carbs are drawing correctly also. I haven't switched the wideband to the rear bank to see those numbers yet, but the mixture screws are very close at this point.

 

How does it feel on power, better, but not huge. I have some more seat time needed, but it seems that maybe the SM needles may be too much for my L24. The reason i say this is because my AFR numbers seem to eventually run below 12 at WOT towards the upper rpms. After some more seat time I might consider installing the original needles back into the SU's to see the number then. Don't know if it is possible to lower the SM needles into the jet to adust mixtures that way.

 

Once i get the AFR number where I am fairly happy, I plan on going back to the dyno to play with timing. I plan on starting at 10 btdc and work my way up to the limit of power. I am still running at 36 total with no detonation, but is this where the best power is at?

 

This wideband is not the end-all tool, but this will be a crucial tuning tool.

[Tony D]

I might suggest you go back to 17.5 at cruise on BOTH carbs and see what you get. It's not a performance setting, but it should run there for daily commuter duties. You might have to retard timing or run premium to keep the pings at bay...

 

Getting below 12.8 past peak torque is way rich. You can pull fuel like a big dog past your peak torque point FAR leaner than most people think. On turbos I have seen numbers into the 13's and EGT/Power was not affected!

 

But to do that on a carb....well... uh... there's a reason I went EFI!

 

Good Luck, and thanks for the detailed update. Interesting read!