924Board.org

[RC]

Since you appear determined to persevere with the CIS, as others have recommended, strongly suggest getting an accurate O2 sensor system or EGA.

For the cost of one modified distributor I can sell you a tried and proven, easy to use, programmable ignition system incorporating a high energy coil driver. Have used it successfully for years and it works perfectly. Just dont need it now as I`ve given CSI the flick and gone EFI.

Roger

[endwrench]

Kudos for opening this up for spirited discussion . My two cents: of coarse, I'm in the EFI camp being one of the first here to go with MS BUT if you are insistent on starting with CIS may I suggest you at least take RC up on his offer of a programmable ignition. If you can control and change the curve you should be able to control whether your engine detonates itself while tuning the CIS. You can start with very little advance and watch (log) your A\F ratios with a (required ) WB. You can begin to dial in more advance while watching for detonation and A\F changes.

If it were me (ha!) I would build and install a MegaJoltLiteJr. This would give you everything you need plus it would migrate very nicely to most any other EFI system you should decide on later. It is based on the Ford EDIS system. You could have this all plugged in and tuned before going EFI so this would be one less variable you would have to deal with. Afterwords, you can just sell the MJLJ unit to some board member and let them start their EFI project.

With that said, don't let EFI intimidate you. If you wait for some sort of Whizzbang Bolt-on Start-on-the-first-crank kit, it ain't ever gonna happen. You might find someone who will be happy to take your money and blow smoke up your ass but in the end, it will be up to you or your tuner to do the hard work of making it right. The process will have back steps and frustrations but in the end it is very satisfying. You are lucky in that there are literally thousands of people who have been there, done that, who will help you out in various message boards. This is especially true with MS. Hell, you have a small army right here on this board who will bend over backwards to help you out. Even Min !

Todd
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'79 924NA. Rebuilt 9.5:1, MSDS header, Mega Squirt Injection, MJLJ-EDIS Ignition, 1.6L Whipple Charger and Intercooler, 10lbs Boost, 944 Trans, Custom HD Clutch.
"simsport" said....superchargers are better than turbos its official!....

[endwrench]

[ideola]

[Min]

[ideola]

to everything you just said.

As noted in the opening post, EFI is under investigation and remains on the roadmap.
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erstwhile owner of just about every 924 variant ever made

[PwrGTOGuy]

Welp, since it's open and i'm game... I'll throw out my "new" plans for my 931.

Well, Initally was going to do efi using an endwrench fuel rail. My MS and EDIS are sitting on my work bench all ready to go... In fact, I had a set of 24lb injectors that I could throw on just to get the system and start it...

But, I have since changed my idears... I'm ditching the stock intake, turbo, exhaust... really, the only thing i'm going to keep is the head and block...

I'm replacing the intake with a custom ITB setup... I'm working with a company now, it will be a surprise, but I think you'll all like it...

I purchase and build my ms and edis for around 400 w/ fuel rail... that would have started the car.

Just my .02 cents... I would love to know where you are sourcing some of those "custom" block and head parts... I had trouble finding places myself... even with your locations on the first page.


Min: wanna hook a brother up when I finally install my MS system?

[ideola]

A lot of the sources for the engine work are local speed shops here in Detroit. Anyone who wants info, I can send the appropriate coordinates, including specific contact people (I find it's best to work with a specific person who has at least seen a Porsche part once or twice). Let me know what you're after, and I will share all the info I have.

{EDIT}
For starters:
Diamond Pistons. Ask for Eric. But whatever you do, don't mention Hausbrauen or Mark Johnston.
Holbrook Racing. Ask for Chris Holbrook. He took over the business his dad started over 50 years ago. Incidentally, he has a car that routinely runs low 6 second quarter miles at the Milan Dragway. Granted, we're not building drag cars, but DAMN! a 6 second car is just unbelievable to see!
Performance Crankshaft doesn't have a web presence...it is basically a one man crank genius operating out of a co-location with Chap Automotive Distributors. The physical location is 2841 E Grand Blvd, Detroit, MI 48211, (313) 873-6588. But you need to call (586)776-1162 and ask for A.W. Brown
Crankshaft Craftsmen is another local resource specializing in crank mods. They do a TON of work, unreal how many cranks are just laying around that place. But I felt more comfortable with AW, plus he was about $100 less.
Crower Rods. Ask for Kerry Novak when you call.
Eurorace is now operating under another name, which escapes me at the moment. In any event, the website is useless. Just call (800)722-8678 and ask for Jorge (that's pronounced "hor-hay", not "George")
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erstwhile owner of just about every 924 variant ever made

[Min]

[macBdog]

Breakdown of my MS costs:

MS unit: $140
Injectors: $90
Fuel rail: $180
TPS, CLT and IAT sensors: $80
Fast Idle solenoid: $40
Braided hose and fittings: $200
Wiring & relays: $40
Steel for pipes and brackets: $20

Total $790

Fuel only. For spark as well prob add on $200 for some EDIS luvin.

Thats including a clean and bench test of injectors and some idiot tax added on from when I shot an injector across the workshop with compressed air and broke the pintle.

EDIT: ok add on $60 for a fuel reg and $50 for an O2 sensor and bung. Hahah. Bung.
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1979 931 with a 350 chev
1973 911E with EFI

[ideola]

Min, it was my challenge, not yours. You've chosen to shut up. I've already documented where I came up with my guestimate on costs for EFI. The true costs for a well-executed MS setup seem to be in the $1100-$1500 range as I've maintained all along. As for the cost of a pro setup, yeah, they're a little more, like maybe double...$1500 for a controller, and then about the same for sourcing all the other bits. So what. I'm not conceding any point at all. And for crying out loud, I've SAID ALL ALONG I'M GOING TO DO EFI. It's just a question of when. And No, I don't really want your IM logs...I was making a point.

Endwrench
You posted some interesting comments regarding flow. Based on what I've read (don't have the practical experience yet), I believe there is merit to the extrude hone and head mods I mentioned for precisely the reasons you posted: better flow=more power. As for Leadfoot's slipping clutch, that is precisely why I'm going with the 915 pressure plate...twice the clamping force of stock

Steve
Regarding your comments on progressive boost, here is what I was thinking (and feel free to correct me if I'm wrong). The K27 cold side seems to be capable of producing the flow requirements I'm looking for. Combine that with a 1.4 spring in the wastegate and a boost controller. The K27 is plenty capable of producing the desired flow at 1.4 bar. I also believe the K27 will produce boost at the RPM range I want. As for low-end torque, well, hopefully the stroke and displacement mods will address some of those issues.

But back to the topic of boost...my understanding of the boost controller is that it allows me to set the desired boost level. Fuel delivery concerns notwithstanding, this is how I was planning to start at a low boost setting, and slowly increment up, carefully monitoring air/fuel (with a wideband setup). So I would be using the same wastegate and turbo combination, just controlling the boost via the controller. I understand that there are diminishing returns at the high end of a compressor's capability, but based on my research, I expect to be right in the sweet spot of what the K27 can do, meaning lots of boost being produced efficiently, translating to lower temps than if I were running a stock K26 setup. If there's a reason you think this won't work, I'm interested.

Here's the K27 unit that will be the basis for my hybrid build:


Here's a compressor map for the K27:

_________________
erstwhile owner of just about every 924 variant ever made

[Raceboy]

Heck, my VEMS conversion AND turbocharging of my white 924 NA cost me 1600$. I did all of the work myself also.
I used ALL new sensors and ignition components.

Going EFI is the best upgrade I've done to 924.
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[morghen]

sorry to budge in...i have chosen not to go EFI myslef...for now.

I was thinking...what the hell are these guys making such a fuss about EFI..besides its still the same gas that goes in and sure the fact that you run EFI with continous injector flow or seqvential is not affecting performance...just fuel consumption...so until now its the same to use CIS or EFI. But then i figured....what if you mod your engine...and because of those mods...the flow between lets say 4000 and 4700 RPM is way way bigger than you would have expected due to unknown or known variables. The CIS has its own fuel pressure and fuel flow curve...the problem seems to be that these curves cannot be altered within a small RPM range....so what EFI offers (i understood this by reading some stuff on some links that i was given by board members, i hope i did not missunderstand ) is a high resolution fuel delivery fully adjustable curve....so when your engine goes lean between 4000RPM and 4700RPM and runs just sweet at all the rest of the RPM...you just put some higher numbers at that RPM range and the injectors open more or whatever the do and the engine runs stoich at all times aprox
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https://www.the924.com

[bass gt]

Dan,

I'm using the TurboSmart boost controller, and i must say it works very well. There are 6 user definable boost levels, and it allows you to clamp the wastegate shut, to prevent creep. This is actually what i use it for.
One thing to think about is running the wastegate seperately from the main exhaust. It will allow the turbo to breathe a lot easier.
Now don't forget that any controller will only allow you to run higher boost levels than the base wastegate spring value. I would recommend fitting a very light spring, or running the wastegate outlet seperate from the main exhaust system. This will effectively lower the wastegate spring value, as there is no reverse pressue on the valve. You can then slowly up the boost with the controller while keeping an eagle eye on the WB Lambda sensor output.
If it's of any interest, i can send you the fuel and ignition charts from my DTA ECU. You can download the software for free to view.
I would recommend using manifold pressure compensations from a base setting as this will follow whatever boost you are running.
I know this has been said a few times already, but i would really reecommend you fit the EFI from the start. If you work out the time/cost for modifying the CIS, which you will then remove, i think it's worth biting the bullet and going the whole hog. Todd ( Endwrench) has more fuel rails coming available in the very near future, and things like coil, injectors, sensors can be had from ebay for buttons. Having no experience of MegaSquirt i can't comment, but a decent ECU can be had again from Ebay and your set.
Whatever route you choose, i sounds a cracking build!.

All the best,

Steve
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Front Wheel Drive is the Devil's work.

[Min]