Just another damned project thread, 914-6 3.2 conversion in GT dress-up Options

[Randal]

I agree, you really need a tuner riding along. I'd give SDS a call. I talked to them a couple of times and they were very helpful.

Dave

I will Dave. I just need to print that page from the manual where you write down all of the tuning so they have an idea of what you are doing.
I wonder if they need all the other stuff as well? O2 logs and such as well as temperatures...

BTW, I'm building an engine for the 240Z soon. I have debated a turbo or a NA 2.8 block with a 280Z intake plenum and a big throttle body. I will go with microsquirt this time.

Come on up and run Cascade Lakes hill climb Rob. You can take the back way through Lassen Park and make a holiday out of the trip.

[DNHunt]

I agree, you really need a tuner riding along. I'd give SDS a call. I talked to them a couple of times and they were very helpful.

Dave

I will Dave. I just need to print that page from the manual where you write down all of the tuning so they have an idea of what you are doing.
I wonder if they need all the other stuff as well? O2 logs and such as well as temperatures...

BTW, I'm building an engine for the 240Z soon. I have debated a turbo or a NA 2.8 block with a 280Z intake plenum and a big throttle body. I will go with microsquirt this time.

I suppose it never hurts to be prepared.

When I had that happen I was really surprised and I finally thought it was a problem with their code because I ended up taking fuel out as I came down the hill and my tune was fine on I-5 again.

Dave

[ConeDodger]

I agree, you really need a tuner riding along. I'd give SDS a call. I talked to them a couple of times and they were very helpful.

Dave

I will Dave. I just need to print that page from the manual where you write down all of the tuning so they have an idea of what you are doing.
I wonder if they need all the other stuff as well? O2 logs and such as well as temperatures...

BTW, I'm building an engine for the 240Z soon. I have debated a turbo or a NA 2.8 block with a 280Z intake plenum and a big throttle body. I will go with microsquirt this time.

Come on up and run Cascade Lakes hill climb Rob. You can take the back way through Lassen Park and make a holiday out of the trip.

When is it Randal?

[ConeDodger]

I agree, you really need a tuner riding along. I'd give SDS a call. I talked to them a couple of times and they were very helpful.

Dave

I will Dave. I just need to print that page from the manual where you write down all of the tuning so they have an idea of what you are doing.
I wonder if they need all the other stuff as well? O2 logs and such as well as temperatures...

BTW, I'm building an engine for the 240Z soon. I have debated a turbo or a NA 2.8 block with a 280Z intake plenum and a big throttle body. I will go with microsquirt this time.

I suppose it never hurts to be prepared.

When I had that happen I was really surprised and I finally thought it was a problem with their code because I ended up taking fuel out as I came down the hill and my tune was fine on I-5 again.

Dave

Dave,
I assume you were tuning with MAP? If so, you were experiencing the same thing as me. I just didn't see it because the car climbed and descended on the trailer... But I am at 4500' here and Mark was tuning at a bit above sea-level.
Sorry for messing with your tune Mark (IMG:style_emoticons/default/sad.gif) It was pretty much nuts-on!

[McMark]

No problem. (IMG:style_emoticons/default/biggrin.gif)

[ConeDodger]

I dropped by a local Porsche shop today. The owner is a PCA member and we are working on an event together. He had an interesting thought... Every once in a while, the car will backfire on start-up. When it does, it usually blows off one of the lines to the common plenum and the idle goes through the roof. He said maybe it damaged the MAP???

Dave? Mark? What do you guys thing of that? I will still be calling SDS when I get the values all written down though... (IMG:style_emoticons/default/blink.gif)

[DNHunt]

I'd say that is a possibility.

[ConeDodger]

He mentioned installing a blow off valve! Really? Can I do that?

[rick 918-S]

Interesting. Maybe you need a blow off valve like the 911's were running... (IMG:style_emoticons/default/idea.gif) Something to cushion the force.

Question: I know nothing about SDS but does it have an 02 sensor to read the emissions and a knock sensor? How come the system doesn't self adjust like the factory EFI cars?

I understand the need to read the engine and tune it out of the gate but then what happens? (IMG:style_emoticons/default/confused24.gif)

[ConeDodger]

Interesting. Maybe you need a blow off valve like the 911's were running... (IMG:style_emoticons/default/idea.gif) Something to cushion the force.

Question: I know nothing about SDS but does it have an 02 sensor to read the emissions and a knock sensor? How come the system doesn't self adjust like the factory EFI cars?

I understand the need to read the engine and tune it out of the gate but then what happens? (IMG:style_emoticons/default/confused24.gif)

I'm still figuring SDS out Rick. I think it seeks Stoichiometric when you use the closed loop mode but that isn't conducive to performance, and having tried it, it didn't seem to adjust very well either. It still went lean under loaded acceleration. They recommend against a knock sensor on VW type engines because they sound like they are knocking all the time apparently.

Pete Stout was critical of aftermarket EFI in a conversation we had a few years back. He said that factory EFI samples many more times per second than aftermarket programmable EFI. SDS allows a setting change every 250rpm. This conversation was back in the Kit Carlson EFI days so it was a while ago... This was back when McMark had a running 914. (IMG:style_emoticons/default/poke.gif) Demeaning look shades on (IMG:style_emoticons/default/shades.gif) Go ahead Mark. Give it your best shot!

[McMark]

There is a start-fuel setting, and I have a feeling that richening that up may stop the occasional cranking-backfire.

[Mike Bellis]

Get one of these. set the spring to pressure. dial it to 2psi and screw to your vacuum manifold.
http://www.mcmaster.com/#brass-relief-valves/=hmysok

[rick 918-S]

With the air cooled element in the equation it makes sense that the thinking and reacting portion of the management would have to be fast, fast, fast. The engine doesn't have the added benifit of stable coolant slowing the change of the environment in the cylinders.

[wndsrfr]

"Every once in a while, the car will backfire on start-up. "

Mine will backfire on hot startups, too. Maybe once out of five or ten times, but it'll give a good bang out the tailpipe--I'm figuring it's maybe cranking one or two revolutions before the ignition part of SDS starts firing but fuel/air left in the cylinders is now in the tailpipe & goes off. Interesting that yours is banging back in the induction end of things....can't quite figure that out unless it's perfectly timed during overlap. You've got a good header system, with no restriction right?
Mine has never blown off the rubber hoses to the MAP 4to1 block--they're really a tight fit & a bear to get off by hand, so that may be why.
I'm sticking with TP sensing--lucky to be on Eastern seaboard & don't get much elevation change between home & event venues....I also see the lean AFR's on light to moderate acceleration when in closed loop but it goes pleasingly rich when I boot it. I use closed loop most of the time in street driving unless I'm thrashing it. It homes in on 14.1:1 pretty reliably but seems to like being rich (like 12:1) if rpm's are below the 2750 notch. (And yes, my CL low limit is set at 1750.)
I'm still blown away by the fact that the car cruises at 60 with the TPS still in the "5" notch and accelerates at the "6" value--meaning that the throttle plates are just barely cracked (the TPS values start at 5 with throttle closed and span up to 50 at WOT). These engines are truly muscular for the car they're in...

[ConeDodger]

Got some props today. I took the 914 for a drive, top off, stereo blaring. I noticed a green Cayman in my rear view mirror. Followed me for about 2 and a half miles through my neighborhood. When I pulled up to a stop light the Cayman pulled along side in the right turn lane. A woman was driving and she looked over, gave me a thumbs up and said "that car is so cool"... I wanted to tell her it was the faux painted flares but the light turned green and she was gone. (IMG:style_emoticons/default/biggrin.gif)

[edwin]

Does the setup you have use a seperate map sensor for atmo correction?
Just about all the aftermarket ecu's I looked at use the second one to adjust fuel for altitude change which could account for your changes.
time to cut the sds plug off and put a megasquirt into this?
What sort of timing values are you using for starting and running?
I had lots of issues with a startup backfire and have changed to some really far out timing and it starts better and no backfire.
When do the seats arrive?
Loving this thread
Edwin

[DNHunt]

Mine will backfire on hot startups, too. Maybe once out of five or ten times, but it'll give a good bang out the tailpipe--I'm figuring it's maybe cranking one or two revolutions before the ignition part of SDS starts firing but fuel/air left in the cylinders is now in the tailpipe & goes off. Interesting that yours is banging back in the induction end of things....can't quite figure that out unless it's perfectly timed during overlap. You've got a good header system, with no restriction right?

Remember, this is a batch fired wasted spark system so there is fuel sitting in the intake and there is a spark every rotation instead of every other rotation. It can fire on the exhaust at the end of the exhaust stroke and during overlap under the right conditions. It is even possible under the right conditions to get it to run backwards. Ask how I know.

Does the setup you have use a seperate map sensor for atmo correction?

This system uses a single MAP reading at startup. The expectation is it should richen as you climb. Restarting the engine at altitude should correct that but his experience is the opposite and so was mine.

Dave

[Mike Bellis]

You need 2 map sensors so it will auto correct on the fly. Not sure if SDS can do this. My Haltech can.

[ConeDodger]

Really just wondered how they looked against the inside. 3/4" total or another 3/4" left to go? I would think another 3/4 would max it out.

Hope this shows what you want Eric... (IMG:style_emoticons/default/smile.gif) The fender wheel arch flange was too close for Mark's comfort and I am sure mine (I wasn't there to see it). I guess there is much more flange on these reproduction flares than on the factory original flares. As you can see here, Mark has done some very nice trimming to make wheel rub a non-issue...

[ConeDodger]

Another... Looks like plenty of room but as we know, the car gains negative camber under acceleration and suspension squat. I will pull one of the rears and see if there has been any rub...

I would say that Harvey knows exactly what he is doing. I had thought 8.5 was all he could do with the 2 - 16X6 wheels he used to make these wheels. Now I believe he knew that it was the limit without extending the flares.