carb conversion
#26
Originally posted by kabooski
what car you drive Ted?
thank you
what car you drive Ted?
thank you
TII's is one thing
Fuel Injection works the best
But for a N/A CARB makes the Best/$- Power
Fuel Injection works the best
But for a N/A CARB makes the Best/$- Power
spending 1.3k on a ECU for a N/A? like to see that
-Ted
#27
Originally posted by BigWoogie
EFI components MIGHT be able to produce the same effect on a N/A, but it would be about three times the cost, ten times the hassle, and take an additional 2 months for fine tuning. I have been down both roads, for NA vehicles I will stick with the carb.
EFI components MIGHT be able to produce the same effect on a N/A, but it would be about three times the cost, ten times the hassle, and take an additional 2 months for fine tuning. I have been down both roads, for NA vehicles I will stick with the carb.
Three times the cost? Jeez, what the hell are you buying, gold-plated injectors?! Of course it costs more, but not three times as much, not even close.
Ten times the hassle? Only if you don't know what you're doing. Ask anyone on this board who's installed a Haltech, it ain't rocket science.
Two months for fine tuning? Fire your tuner, he obviously has no idea. Two days maybe.
#28
By the way, my buddies car is already modified. It is so loud you can't ride in it for long anyway. It has a cold air intake, Mazdatrix headers, resonator and exhaust. It is louder than my Vette which has huge headers, no cat and a Borla catback.
Am I missing something? How are you hardcore EFI people setting up your computers? Are custom chips readily available for these cars? Halltech makes a computer for a rotary for like $1600. Then you need someone to install and dyno tune it. Probably another $500. Maybe you could use an APEXI unit, but again very expensive and very difficult to tune. I can see doing something like this on a turbo car or a vette, but not for this car.
I don't really know much about rx7 efi systems, but they seem to be very different then Volvo, Porsche, or Chevy systems I am familiar with. The TPS on this GTU was like $200 and is very complex. The one on my vette cost like $20 and is a simple rheostat. I don't know of anyone locally who fully understands the RX7 efi or is capable of reprogramming it.
The only semi-local rx7 specialist (Sun Auto) doesn't think this car will run right with its factory computer. Currently, it is running slightly lean b/c the computer cannot supply enough fuel. In my vette I would just add more fuel pressure or get a new chip burned, but my buddy thinks its hopeless with this Mazda efi.
Am I missing something? How are you hardcore EFI people setting up your computers? Are custom chips readily available for these cars? Halltech makes a computer for a rotary for like $1600. Then you need someone to install and dyno tune it. Probably another $500. Maybe you could use an APEXI unit, but again very expensive and very difficult to tune. I can see doing something like this on a turbo car or a vette, but not for this car.
I don't really know much about rx7 efi systems, but they seem to be very different then Volvo, Porsche, or Chevy systems I am familiar with. The TPS on this GTU was like $200 and is very complex. The one on my vette cost like $20 and is a simple rheostat. I don't know of anyone locally who fully understands the RX7 efi or is capable of reprogramming it.
The only semi-local rx7 specialist (Sun Auto) doesn't think this car will run right with its factory computer. Currently, it is running slightly lean b/c the computer cannot supply enough fuel. In my vette I would just add more fuel pressure or get a new chip burned, but my buddy thinks its hopeless with this Mazda efi.
#29
Rotary Enthusiast
Joined: Mar 2001
Posts: 1,273
Likes: 0
From: Ft. Worth, Texas, USA, Earth, Solar System...
Originally posted by kabooski
what car you drive Ted?
thank you
TII's is one thing
Fuel Injection works the best
But for a N/A CARB makes the Best/$- Power
spending 1.3k on a ECU for a N/A? like to see that
----------------------------------
88 GXL
87 SE
87 TII
...etc
what car you drive Ted?
thank you
TII's is one thing
Fuel Injection works the best
But for a N/A CARB makes the Best/$- Power
spending 1.3k on a ECU for a N/A? like to see that
----------------------------------
88 GXL
87 SE
87 TII
...etc
Brad
#31
you made the decision Felix to go with a webber setup
holly manifold $199-250
Holly 600 $225-280
Jegs/Summit
Lets say 280 for a Holly Carb
and $880 (price given by HitMan (matt) F9A with 3 bar etc
does not include the price of a laptop
or it's tunning
are not the SAME PRICE rx7_ragtop -not even close
I bet you all my cars that there are more people running carb set-up
in FC N/A's then there are people running stand-alones!
holly manifold $199-250
Holly 600 $225-280
Jegs/Summit
Lets say 280 for a Holly Carb
and $880 (price given by HitMan (matt) F9A with 3 bar etc
does not include the price of a laptop
or it's tunning
are not the SAME PRICE rx7_ragtop -not even close
I bet you all my cars that there are more people running carb set-up
in FC N/A's then there are people running stand-alones!
#32
You're running into trouble trying to run a "normal" Holley carb on a rotary... unless you do some special tricks to the intake manifold
I know someone with a Edelbrock 600 on a half-bridge 12A, says it runs QUITE well thank you!
As for myself when it comes to modifying N/As I will always prefer a carburetor, until complete EFI setups (THIS INCLUDES: fuel pump, injectors, modifying manifold w/injector bungs, wiring harness, computer, AND the hardware necessary to program the computer (need laptop? that's part of the system IMO as otherwise I don't need one) cost less than a carb setup, it ain't happening! Carbs have specific advantages over EFI. They're not perfect, but they're plenty good enough.
I contemplated switching to an SDS computer. This would have cost me a minimum of $1000 with accessories and this is probably the cheapest EFI solution on the market, both because it's affordable on the surface and because it doesn't require I spend more money on a laptop so I can tune it.
Even if I'd bought the most expensive carb setup, and an assortment of jets and air bleeds in the ranges I'd need, I doubt I could spend over $1000. MAYBE if I bought that sweet TWM dual 40DCOE carb setup, which is $950 out the door if I'm not mistaken. But that setup is supposed to have more power potential than even a 51IDA while still maintaining good streetability! Knowing what I know about the mods needed to run a "normal" Holley on a rotary, a total carb conversion cost in the neighborhood of $300-350 is more like it. (Most of that being in the $230 intake manifold) The end result will totally SPANK what you could do with that for the stock EFI setup. You can pick up used carbs for $50-75, even the most expensive rebuild kits with goodies like reuseable float bowl gaskets cost $30. I was able to fashion a linkage for the stock throttle cable to a Holley carb for $2.99 - bought a GM linkage pivot and borrowed a piece off of a junk Nikki (1st-gen) carb. Done. I went so far as to make an adapter to mate a Holley to a stock 1st-gen manifold - cost was $20 in parts. Never got around to putting the carb on, however. (The carb I had, I got basically for free - grabbed it off of one of my cars before having it towed to the junkyard) I do intend on continuing my conversion at a later date...
I know someone with a Edelbrock 600 on a half-bridge 12A, says it runs QUITE well thank you!
As for myself when it comes to modifying N/As I will always prefer a carburetor, until complete EFI setups (THIS INCLUDES: fuel pump, injectors, modifying manifold w/injector bungs, wiring harness, computer, AND the hardware necessary to program the computer (need laptop? that's part of the system IMO as otherwise I don't need one) cost less than a carb setup, it ain't happening! Carbs have specific advantages over EFI. They're not perfect, but they're plenty good enough.
I contemplated switching to an SDS computer. This would have cost me a minimum of $1000 with accessories and this is probably the cheapest EFI solution on the market, both because it's affordable on the surface and because it doesn't require I spend more money on a laptop so I can tune it.
Even if I'd bought the most expensive carb setup, and an assortment of jets and air bleeds in the ranges I'd need, I doubt I could spend over $1000. MAYBE if I bought that sweet TWM dual 40DCOE carb setup, which is $950 out the door if I'm not mistaken. But that setup is supposed to have more power potential than even a 51IDA while still maintaining good streetability! Knowing what I know about the mods needed to run a "normal" Holley on a rotary, a total carb conversion cost in the neighborhood of $300-350 is more like it. (Most of that being in the $230 intake manifold) The end result will totally SPANK what you could do with that for the stock EFI setup. You can pick up used carbs for $50-75, even the most expensive rebuild kits with goodies like reuseable float bowl gaskets cost $30. I was able to fashion a linkage for the stock throttle cable to a Holley carb for $2.99 - bought a GM linkage pivot and borrowed a piece off of a junk Nikki (1st-gen) carb. Done. I went so far as to make an adapter to mate a Holley to a stock 1st-gen manifold - cost was $20 in parts. Never got around to putting the carb on, however. (The carb I had, I got basically for free - grabbed it off of one of my cars before having it towed to the junkyard) I do intend on continuing my conversion at a later date...
#33
Originally posted by kabooski
Lets say 280 for a Holly Carb
and $880 (price given by HitMan (matt) F9A with 3 bar etc
does not include the price of a laptop
or it's tunning
Lets say 280 for a Holly Carb
and $880 (price given by HitMan (matt) F9A with 3 bar etc
does not include the price of a laptop
or it's tunning
proves you guys don't do your research why would you need a 3 bar map for an n/a?????
afc=$300
porting the intake=easy
removing the 6 port sleeve=easy
tunning= take it do the dyno (and you can see how much HP it makes)
Tunning is not that hard.......... when the pettle drops the bullshit stops
#35
Rotary Enthusiast
Joined: Mar 2001
Posts: 1,273
Likes: 0
From: Ft. Worth, Texas, USA, Earth, Solar System...
Originally posted by kabooski
you made the decision Felix to go with a webber setup
holly manifold $199-250
Holly 600 $225-280
Jegs/Summit
Lets say 280 for a Holly Carb
and $880 (price given by HitMan (matt) F9A with 3 bar etc
does not include the price of a laptop
or it's tunning
are not the SAME PRICE rx7_ragtop -not even close
I bet you all my cars that there are more people running carb set-up
in FC N/A's then there are people running stand-alones!
you made the decision Felix to go with a webber setup
holly manifold $199-250
Holly 600 $225-280
Jegs/Summit
Lets say 280 for a Holly Carb
and $880 (price given by HitMan (matt) F9A with 3 bar etc
does not include the price of a laptop
or it's tunning
are not the SAME PRICE rx7_ragtop -not even close
I bet you all my cars that there are more people running carb set-up
in FC N/A's then there are people running stand-alones!
Brad
#36
[QUOTE]Originally posted by peejay
dyno time = lots of $$$[QUOTE]
Maybe an hour or two just to get things running; typical prices are $30-$100/hour.  if you're bitching about that much money, you shouldn't be owning an FC in the first place.
Pretty big blanket statement...versus what?  A stand-alone?  Sure, on something that would cost 2-3 times as much, and 10 times harder to install.  The S-AFC does a fine job for MOST people.
-Ted
dyno time = lots of $$$[QUOTE]
Maybe an hour or two just to get things running; typical prices are $30-$100/hour.  if you're bitching about that much money, you shouldn't be owning an FC in the first place.
afc = very poor way of tuning EFI - only adjusts things two-dimensionally, so you end up with rich spots and lean spots
-Ted
#37
Originally posted by kabooski
you made the decision Felix to go with a webber setup
you made the decision Felix to go with a webber setup
Plus try autoxing with that thing and having the float bowls run dry
#39
Originally posted by rx7_ragtop
And that stock Holley is NOT going to work properly on a rotary... it needs to be modified. (idle circuit and enrichment curve...) I think you can still get one from Mazdatrix with the proper modifications already done. Not for $280 though...
Brad
And that stock Holley is NOT going to work properly on a rotary... it needs to be modified. (idle circuit and enrichment curve...) I think you can still get one from Mazdatrix with the proper modifications already done. Not for $280 though...
Brad
RB is really ripping people off with the Holley kits. I understand the need to recoup R&D losses, and that's all fine and good, have no problem with that... but they charge you $200 for "Race Float Bowls" that you can buy at any speed shop for $40-50. Hello MARKUP!!! Most decent Holleys already come with center-hung bowls anyway!
#40
Rotary Enthusiast
Joined: Mar 2001
Posts: 1,273
Likes: 0
From: Ft. Worth, Texas, USA, Earth, Solar System...
Originally posted by kabooski
it's clear your clueless on Haltech products ragtop
how much is the E6k $800???
HAHA!
Ask Jason how much the F9A is eh
or visit rx7.com
it's clear your clueless on Haltech products ragtop
how much is the E6k $800???
HAHA!
Ask Jason how much the F9A is eh
or visit rx7.com
Any more comments?
#41
sure $800
show me where
F9 basic is $715 F9A is more
plus map sensor
sensors etc
laptop $300 used
600 holly $250 new
6 port manifold J.W $199
$500 carb setup
$1,200 EFI
hmm got math?
performance = same (non-turbo)(non-road-race use)
show me where
F9 basic is $715 F9A is more
plus map sensor
sensors etc
laptop $300 used
600 holly $250 new
6 port manifold J.W $199
$500 carb setup
$1,200 EFI
hmm got math?
performance = same (non-turbo)(non-road-race use)
#42
Originally posted by peejay
dyno time = lots of $$$
afc = very poor way of tuning EFI - only adjusts things two-dimensionally, so you end up with rich spots and lean spots
dyno time = lots of $$$
afc = very poor way of tuning EFI - only adjusts things two-dimensionally, so you end up with rich spots and lean spots
I only said the afc because I thought it would be cheeper than your carb setup and would allow tunning. I never said it was top of the line but ,it is compared to a carb.
#43
Racing Beat said the carb will come jetted properly for my buddies set up. I think the whole setup costs around $850. They say just bolt on and do the final adjustments (mix and idle, I assume). At the same time, I'm trying to talk my buddy, Tom, into one of those seperate reservoirs with Royal Purple 2 cycle oil and a PCV Technologies electronic oil pump. Hopefully this motor will last a little longer and go faster than the last one.
Dave Seel
Dave Seel
#44
Rotary Enthusiast
Joined: Jan 2002
Posts: 975
Likes: 5
From: Puerto Rico Land Of The Fastest Rotaries
Look NZ... The carb conversion allows more performace with less money, If you want a reasonable argument check this out... How much money does it take to make a street F.I. rotary car run in the low 11's/ Don't answer.. the answer is A LOT!!!!!... My best friend has a 1985 100% street RX-7 with holley and turbo, he uses it everyday to work and it still makes constant 11:3's on the strip with the whole exhaust system installed. But since you don't sound to know much about the subject and heve no experience maybe just heard a lot but haven't done anything yourself, I will stop right here. By the way when I reffered to the 7 second car it was so that you would have no doubt about the power of a carburator, I guess the only argument you had was "so what" because you did not realized or analized what I was saying. By the way... How fast is your car?.... Ohh!!!! i forgot mine runs constant in the 12:3's so you won't have to ask... That is why Puerto Rico has the fastest cars!!!!! We do not think we know it all but we allways beat those who say they do.... Funny isn't it? I guess not for you... Where can I see that famous auzzie drag car??? links????
#45
The more I learn about these cars the more questions I have. We already took off the air pump, so this means his 6 ports aren't opening now? I thought it just fed fresh air to the cat like on my corvette. I did a quick search on this forum and the general consensus was take that POS off. I guess that is for the older cars. So with this new Racing Beat manifold and carb, that eliminates the need to wire open the 6 port sleeves, get a new actuator or get pinapple racing sleeves right?
Please help....Thanks for all the replies
Edit: I have been using the search feature a lot. I see air pumps have been discussed extensivly, but it is really hard to find answers relating to a carb conversion. Sorry if I am bringing up things you guys are bored with.
Please help....Thanks for all the replies
Edit: I have been using the search feature a lot. I see air pumps have been discussed extensivly, but it is really hard to find answers relating to a carb conversion. Sorry if I am bringing up things you guys are bored with.
Last edited by blackvette; 02-09-02 at 11:56 AM.
#46
Well, the manifold and carb won't be here for 2 weeks. So since the air pump is already removed, we wired open the VDI and just left the 5,6 ports closed. He says the car feels a little quicker at the high rpms and that was with me in the car.
He also ordered 2 MSD 6AL units.
Still, I am wondering what to do with the 5, 6 ports after the conversion. Should he order some new fixed sleeves or just remove them?
He also ordered 2 MSD 6AL units.
Still, I am wondering what to do with the 5, 6 ports after the conversion. Should he order some new fixed sleeves or just remove them?
#47
Originally posted by Angel Guard Racing Team
Look NZ... The carb conversion allows more performace with less money, If you want a reasonable argument check this out... How much money does it take to make a street F.I. rotary car run in the low 11's/ Don't answer.. the answer is A LOT!!!!!... My best friend has a 1985 100% street RX-7 with holley and turbo, he uses it everyday to work and it still makes constant 11:3's on the strip with the whole exhaust system installed. But since you don't sound to know much about the subject and heve no experience maybe just heard a lot but haven't done anything yourself, I will stop right here. By the way when I reffered to the 7 second car it was so that you would have no doubt about the power of a carburator, I guess the only argument you had was "so what" because you did not realized or analized what I was saying. By the way... How fast is your car?.... Ohh!!!! i forgot mine runs constant in the 12:3's so you won't have to ask... That is why Puerto Rico has the fastest cars!!!!! We do not think we know it all but we allways beat those who say they do.... Funny isn't it? I guess not for you... Where can I see that famous auzzie drag car??? links????
Look NZ... The carb conversion allows more performace with less money, If you want a reasonable argument check this out... How much money does it take to make a street F.I. rotary car run in the low 11's/ Don't answer.. the answer is A LOT!!!!!... My best friend has a 1985 100% street RX-7 with holley and turbo, he uses it everyday to work and it still makes constant 11:3's on the strip with the whole exhaust system installed. But since you don't sound to know much about the subject and heve no experience maybe just heard a lot but haven't done anything yourself, I will stop right here. By the way when I reffered to the 7 second car it was so that you would have no doubt about the power of a carburator, I guess the only argument you had was "so what" because you did not realized or analized what I was saying. By the way... How fast is your car?.... Ohh!!!! i forgot mine runs constant in the 12:3's so you won't have to ask... That is why Puerto Rico has the fastest cars!!!!! We do not think we know it all but we allways beat those who say they do.... Funny isn't it? I guess not for you... Where can I see that famous auzzie drag car??? links????
I'll be the first to admit the FC EFI is crap, but it's also 15 years old, dark ages in computer terms. That's why so many convert to Haltech or the like. I also never said carbs weren't cheaper, but for overall performance, EFI is worth the extra money. You say it cost alot to get an EFI car to do 11's. That applies to any car! By the time you have the hardware to do 11's, the additional cost of EFI compared to the total cost of the project is stuff all.
Last edited by NZConvertible; 02-10-02 at 09:08 PM.
#48
Originally posted by NZConvertible
You seem to be taking my comments very personally. I couldn't care less if you run a carb, but I won't. For the record, I never said my car was fast, or even implied it. Hell, it's basically stock at the moment. Some of us are on limited funds and work on daily drivers. But you would be very mistaken to equate this to a lack of knowledge or experience. You seem obssesed with drag racing and that's fine, but is hardly a logical place to compare carbs to EFI. WOT for 10-15 sec is a fraction of the tuning range for a street driven car. A carb doesn't "make" power, it's just a way of getting fuel into the intake air. Can a carb provide full 3D mapping of fuel and ignition, accurate cold-start enrichment, temperature and altitude correction, turbo boost control, electric fan control, data logging, blah, blah... Not even close. It delivers fuel, and not very accurately. That's all. It's a proven fact that if an EFI system flows the same amount of air as the carb it's being compared to (and is well tuned, same as carbs), there will be power and torque improvements throughout the rev range, only small up top but significant in the low-mid range, with improved driveability, simply because of the accuracy of the fuel injection and ignition timing. This is fact, you can't dispute it. Or are all the world's car manufacturers completely wrong?
I'll be the first to admit the FC EFI is crap, but it's also 15 years old, dark ages in computer terms. That's why so many convert to Haltech or the like. I also never said carbs weren't cheaper, but for overall performance, EFI is worth the extra money. You say it cost alot to get an EFI car to do 11's. That applies to any car! By the time you have the hardware to do 11's, the additional cost of EFI compared to the total cost of the project is stuff all.
You seem to be taking my comments very personally. I couldn't care less if you run a carb, but I won't. For the record, I never said my car was fast, or even implied it. Hell, it's basically stock at the moment. Some of us are on limited funds and work on daily drivers. But you would be very mistaken to equate this to a lack of knowledge or experience. You seem obssesed with drag racing and that's fine, but is hardly a logical place to compare carbs to EFI. WOT for 10-15 sec is a fraction of the tuning range for a street driven car. A carb doesn't "make" power, it's just a way of getting fuel into the intake air. Can a carb provide full 3D mapping of fuel and ignition, accurate cold-start enrichment, temperature and altitude correction, turbo boost control, electric fan control, data logging, blah, blah... Not even close. It delivers fuel, and not very accurately. That's all. It's a proven fact that if an EFI system flows the same amount of air as the carb it's being compared to (and is well tuned, same as carbs), there will be power and torque improvements throughout the rev range, only small up top but significant in the low-mid range, with improved driveability, simply because of the accuracy of the fuel injection and ignition timing. This is fact, you can't dispute it. Or are all the world's car manufacturers completely wrong?
I'll be the first to admit the FC EFI is crap, but it's also 15 years old, dark ages in computer terms. That's why so many convert to Haltech or the like. I also never said carbs weren't cheaper, but for overall performance, EFI is worth the extra money. You say it cost alot to get an EFI car to do 11's. That applies to any car! By the time you have the hardware to do 11's, the additional cost of EFI compared to the total cost of the project is stuff all.
you couldn't have said it better " A carb doesn't "make" power, it's just a way of getting fuel into the intake air. " yeah a pour way. it's like in cooking using a messuring cup or not. it's just not accurate.
#49
Junior Member
Joined: Aug 2001
Posts: 33
Likes: 0
From: Southern California
Originally posted by amemiya
you couldn't have said it better " A carb doesn't "make" power, it's just a way of getting fuel into the intake air. " yeah a pour way. it's like in cooking using a messuring cup or not. it's just not accurate.
you couldn't have said it better " A carb doesn't "make" power, it's just a way of getting fuel into the intake air. " yeah a pour way. it's like in cooking using a messuring cup or not. it's just not accurate.
How many of the bashers have ever attempted a carb set-up on a 6-port? Just curious...