Carbureted street 944?
#17
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How hard is it really to tune an ITB car, specifically a turbo car? You can easily get a set of honda CBR1000 44mm butterflies and linkage for 40 bucks, and then all it takes is a spare intake and a bit of fab and you're done. I bet I could put together a working ITB intake for around 75 bucks.
#18
Nordschleife Master
How hard is it really to tune an ITB car, specifically a turbo car? You can easily get a set of honda CBR1000 44mm butterflies and linkage for 40 bucks, and then all it takes is a spare intake and a bit of fab and you're done. I bet I could put together a working ITB intake for around 75 bucks.
Can and has been done, maybe Michael Mount will chirp in and add his great knowledge on the subject...
#19
okay so I have to weigh in....
I really didnt want to bother....
I am completely wishy washy on the subject.
My first pcar was a 79 924....WITH WEBER CARBS.
However, I owned 2 60-70s american cars with carbs before it.
3 carbed VW engines for land, one for sea, and a half of one in an ultralight.
I wont bother with the number of fuel injected engines Ive owned since.
Fuel injection is more efficient. It is more precise. It is more dynamic.
Fuel injection will get you the most power at the best fuel cost when properly tuned....99% of all fuel injected cars are not well tuned nor readily tunable as equipped from the factory.
A carburated engine is often more powerful then a comparable fuel injected engine....when the carb is well adjusted and the vehicle properly tuned....which while somewhat voodoo in nature, is a skill easily acquired.
A carburated engine will only rarely match the efficiency of a fuel injected engine....when it does tuning is somewhat responsible...but more often its Operator driving style.
You can show exploded diagrams of carburetors with 100+ small parts....thats usually the response to one of these threads. We could do a component count of each resistor capacitor diode chip and transistor in a fuel injections brain....and hit 100+ as well.
I wouldnt convert my 944 to a carb....but Ill probably hit josh up when I get my next car...because stock tuning certainly lacks something to be desired, and the afm never made sense to me.
I wouldnt have converted my 924 back to fuel injection.
If any carb car Id owned had a problem....I could and have stripped cleaned and jerryrigged replacement parts anywhere....even a middle of nowhere kansas motel room. whoever said PITA on the road....I couldnt disagree more.
Most of the FI cars Ive owner would have been an easy junkyard away from repair.
I keep 4 injectors, a spare dme, 3 dme relays, a spool of wire, and an electrical kit in my 944.....because I dont have the same confidence in the parts availability in random locales.
So I guess,
in my mind.....carbs get the job done, and are easily serviced without special tools or skills.
FI is far more efficient though not as serviceable even with tuning capabilities added to the system.
Its the age old chocolate or vanilla.
Thats my .02 take it or leave it
I really didnt want to bother....
I am completely wishy washy on the subject.
My first pcar was a 79 924....WITH WEBER CARBS.
However, I owned 2 60-70s american cars with carbs before it.
3 carbed VW engines for land, one for sea, and a half of one in an ultralight.
I wont bother with the number of fuel injected engines Ive owned since.
Fuel injection is more efficient. It is more precise. It is more dynamic.
Fuel injection will get you the most power at the best fuel cost when properly tuned....99% of all fuel injected cars are not well tuned nor readily tunable as equipped from the factory.
A carburated engine is often more powerful then a comparable fuel injected engine....when the carb is well adjusted and the vehicle properly tuned....which while somewhat voodoo in nature, is a skill easily acquired.
A carburated engine will only rarely match the efficiency of a fuel injected engine....when it does tuning is somewhat responsible...but more often its Operator driving style.
You can show exploded diagrams of carburetors with 100+ small parts....thats usually the response to one of these threads. We could do a component count of each resistor capacitor diode chip and transistor in a fuel injections brain....and hit 100+ as well.
I wouldnt convert my 944 to a carb....but Ill probably hit josh up when I get my next car...because stock tuning certainly lacks something to be desired, and the afm never made sense to me.
I wouldnt have converted my 924 back to fuel injection.
If any carb car Id owned had a problem....I could and have stripped cleaned and jerryrigged replacement parts anywhere....even a middle of nowhere kansas motel room. whoever said PITA on the road....I couldnt disagree more.
Most of the FI cars Ive owner would have been an easy junkyard away from repair.
I keep 4 injectors, a spare dme, 3 dme relays, a spool of wire, and an electrical kit in my 944.....because I dont have the same confidence in the parts availability in random locales.
So I guess,
in my mind.....carbs get the job done, and are easily serviced without special tools or skills.
FI is far more efficient though not as serviceable even with tuning capabilities added to the system.
Its the age old chocolate or vanilla.
Thats my .02 take it or leave it
#21
Three Wheelin'
I know 1st hand what is it takes to install ITB's on a P-car, have done it with 924, 944 and 993. And I made ITB's myself+installed standalone ECU and also tuned them.
My race-car has ITB's+turbo.
And the cars are running at least as good as stock cars in traffic, just snappier and more lively.
I would never install carbs as ITB's+ECU has way more driveability and there is NO power advantage when using carbs compared to ITB's.
931:
993:
#24
Always wondered about mounting 4 Harley Mikunis on my since gone 84. Using rubber carb runners to manifold stubs would simplify mounting. When I bought my Harley had choice of FI of carburetor (all FI now). Took the carb, I can work on it. Carbs are all most always used on big inch strokers for power.
Last edited by jhowell371; 09-27-2013 at 10:27 AM. Reason: spelling
#25
just like some here, i really like the ability to mess with the tuning myself, instead of depending on someone else. i'd welcome it, get those injectors and some electronics out, it certainly takes a skill though.
i say if you've got multiple 944s, do it with one, just because.
i know i would.
also, come on ... doesn't that just look really really good???
i say if you've got multiple 944s, do it with one, just because.
i know i would.
also, come on ... doesn't that just look really really good???
#26
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Just a clarification here.
I do have the DME Tuner - this combined with one of my MAF kits gives you full control over the DME. You can tune fuel, ignition timing, rev-limit, idle speed, accel enrichment, warm-up fueling, coil dwell, ect, ect.
This is stand-alone level of control.
That said, I do think ITBs are cool - and I have thought quite often about making a set for my own 944NA. Obviously it would still be fuel-injection. However, I tend to believe the limiting factor on the car isn't the intake manifold, but the head/port/valve.
I do have the DME Tuner - this combined with one of my MAF kits gives you full control over the DME. You can tune fuel, ignition timing, rev-limit, idle speed, accel enrichment, warm-up fueling, coil dwell, ect, ect.
This is stand-alone level of control.
That said, I do think ITBs are cool - and I have thought quite often about making a set for my own 944NA. Obviously it would still be fuel-injection. However, I tend to believe the limiting factor on the car isn't the intake manifold, but the head/port/valve.
#27
Pro
Carbs just make so much lovely noise too. Throttle bodies would be an interesting route also?
#28
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Rob, surely you aren't presuming to tell me what I have control of or not with the DME?
Maximum injectors are not 80#. 120# are the largest I've currently tried, and doubt there are more then a handful of 951's needing anything more. There is exactly zero 944NAs which need even 80# injectors - so being able to control larger is a moot point.
Regardless, all stand-alones have limitations. A limitation does not change what it is.
Maximum injectors are not 80#. 120# are the largest I've currently tried, and doubt there are more then a handful of 951's needing anything more. There is exactly zero 944NAs which need even 80# injectors - so being able to control larger is a moot point.
Regardless, all stand-alones have limitations. A limitation does not change what it is.
#29
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A 160# fifth injector + 4 80# injectors does not equal 120# injectors.
Saying that a reverse engineered 80's ECU is a standalone is pushing it. Once again, a standalone gives you complete control over it and can easily be installed on any engine. Not only that, but even the cheap DIY standalones destroy that Bosch ECU in not only abilities, but in processing power and memory as well.
Saying that a reverse engineered 80's ECU is a standalone is pushing it. Once again, a standalone gives you complete control over it and can easily be installed on any engine. Not only that, but even the cheap DIY standalones destroy that Bosch ECU in not only abilities, but in processing power and memory as well.
I did notice that you didn't actually answer my question.
If I wanted, I could install the DME on my motorcycle, or Wife's car. So it meets your arbitrary amateur criteria.
I will agree that there is newer hardware out there. But that does not inherently make it better. MS has gone through plenty of issues of its own.
You might not get this, but not everyone wants to, or has the capability of doing a complete stand-alone.
#30
Nordschleife Master
I still think it would be a good project just for kicks, keep it simple maybe ITBs controlled by MAF & TPS only. A stable vacuum is a pain on ITBs therefore MAP causes more problems than its worth anyway. One ITB intake is normally sufficient vac for brakes and auxiliaries (HCV/FP) from what I've seen. Electromotive DFUs for spark.
You don't really need a larger diameter intake or bigger valves, its air velocity not volume that is needed. I'd really like to know how to harmonically balance ITB intakes to get a soundwave boost from them, heard about it but its beyond me.
You don't really need a larger diameter intake or bigger valves, its air velocity not volume that is needed. I'd really like to know how to harmonically balance ITB intakes to get a soundwave boost from them, heard about it but its beyond me.