loudazzrx7

iTrader: (6)

whats up mazda speed7 we should hook up and see what that n/a 7 of your can really do. 86 n/a 14.19 at 96mph --60foot 2.19 here---i hate going to the tracks and seeing n/a run high 16s and even 17s--check out the times at rx7.com--it gives you a list of some of the fastest n/a in the world.

Poindexter10thae

iTrader: (2)

Yes, you have to get all the fuel equipment. With this setup the S-AFC is absolutely useless. The S-AFC is a fuel computer that adjusts fuel/air ratio by modifying the air-flow meter/MAP sensor signal. Once you do the carb conversion you will no longer have a A/F meter or a MAP sensor, these things are only found in ELECTRONIC FUEL INJECTION systems, with a carburetor you are converting to a MECHANICAL Fuel system. The S-AFC does not control fuel pressure either, fuel pressure is determined by
1. fuel pump
2. a Fuel pressure regulator

It is absolutely essential that you switch to a low pressure fuel pump with a Carb. If you dont it simply wont work. It is similar in principle to some of the T2 owners in the forum rewiring a FD fuel pump in their T2.

Ryde _Or_Die

Do you have any idea approx. how much Hp could be made with the carb/header/true-dual exhaust/pulleys/etc? Basically everything you can do while staying NA. With that extra 30-40 HP seems like you can get up to around 210rwhp or so if my very quick guestimation is right.

Gimpdiggity

I'm gonna have to do that throttle body mod. That looks pretty clean, and cheap!!!

FPrep2ndGenRX7

I want to see some dyno runs of a 2nd gen with a stock port motor making the claimed 230-240 HP. That would roughly be 190 HP+/- at the rear tires? It just sounds to good to be true which I think it is. Now 190 HP stock port engine sounds possible with 160 HP+/- to the rear tires.

There are numerous people on the forum that don't believe those HP numbers are possible and we simply want proof. We've seen the proof for the 160 HP to the rear tires but not much more unless its ported.

mprime

What a great thread so far! I have always wondered what switching to a carb set upi would do and how much more HP it would give you.

I have for a long time been considering what it would be like when I need to replace my current engine with a street ported rebuild and an Atkins SC with the Holley carb running on my already oopen exhaust setup and intake.

But I was never real sure about the running a carb set up intstead of F.I. everyone I have asked has just said it not worth swtiching to a carb but never explained why. why stay with F.I. when I can run a SC ported rotory?

Also if that air chart is correct then those headlaight intakepieces are worthless.

My only thought is that drivability and fuel economy would drop straight through the floor.

wankelhead

hey roy-what mods did you run thet 14.19 with?
d

mazdaspeed7

What was your 1/8 time and mph for that run? The only track near me is an 1/8 mile. I havent been lately, but I think I will be hitting very low 9's. I think Ill go next week when I finish the Mustang MAF sensor conversion for my car.

NCsublime

I'm definitely not claiming to be the fastest NA. . .not even on this thread, but I bet I could give you guys a run for your money. I have a little tuning to finish up, but my major mods are already completed. I can run about a 14.5 sec. 1/4 mile. I have a Bonez intake w/custom cold air box, pacesetter header, bonez mid-pipe and apexi' n1 duals-10mm magnecor plug wires with NGk plugs. An 87' TII tranny and diff. with 4:30 ring and pinion, and have just recently completed the ATF cleansing in order to regain most of my compression. I will soon be adding an upgraded ECU, ignition amp, pulley set, and TII fuel pump. I think I also may do the TB mod and remove some emmissions equip. that I'm not using. I haven't done anything to remove any weight yet. I've also got some 16" chrome wheels that I'm looking to sell so I can get some 17" alloys (maybe white ones to match my car). I have bonez cross-drilled rotors (which BTW have NO cracks whatsoever and I've had them for over 3 years) and SS brake lines and aftermarket pads. That's most of my mods. My suspension needs replaced pretty bad, and I'm planning on getting a whole suspension kit with strut bars, springs, etc to replace my stock stuff. Anyone have any suggestions?

Good luck guys-Peace,

Derek

PaulC

I can belive it My best (and most perfect run that I will never duplicate) I ran a15.0 at 86mph and a 1.84 60'. I was also ina completly stripped down car and had mounted a well used pair of 245/50 nitto's on my rims. Im averaging 15.8-15.9 at 85-87mph with the interior back in (and stereo)and my new Kuhmo's.

How ever I just sold the T2 drive train I had (guy offered twice what I paid). So I want to build a bad NA now. the T2 conversion just looked problimatic.

wankelhead

hmm..i was pretty sure that all t2 rear ends where 4.10...am i incorect?

http://www.mazdatrix.com/g5.htm

NCsublime

No, you are absolutely correct. I originally had a 3:90 final gear ratio when my car used to be an automatic with the stock diff. Then I bought a used TII diff before I started my auto to manual tranny swap and had 4:30 gears that I bought from Mazdatrix compressed into the used TII diff. That make sense?

Speed Addict

Have you considered a ported Fuel-injected SC rotary? SuperchargedRex runs 209 RWHP with his setup (hmm, more than a stock TII, way more ~255HP at motor), He only runs 8-10 PSI boost.

I plan on upgrading my fuel injection and going for 450+HP from a EFI SC setup w/a half bridgeport motor. (I don't think you can get that much from a carbuerated set-up).

Sorry to burst the bubble, but...
Have you ever seen a carbuerated VIPER or Late model Ferrari (I don't meen a drag-only car either)?
Carbs are a thing of the past. Mazda's 4-rotor that won at LeMans was Fuel injected. The Carb setup may be cheaper, but I think you would sacrifice future upgradability by switching.

mprime

"Have you considered a ported Fuel-injected SC rotary?"

Sure but Who makes one no one I know of anymore

"I plan on upgrading my fuel injection and going for 450+HP from a EFI SC setup w/a half bridgeport motor. (I don't think you can get that much from a carbuerated set-up)."

That would be sweet!

"Carbs are a thing of the past."

Sure I realize that but it's fun to speculate. Believe me I would love to get a FI SC system that would bolt on like the old Paxton but unless you know of someone thats making them in secret what other SC is out there?

peejay

(watching with interest, planning my FC)

One nice thing about N/As is that they don't self destruct when you run 'em lean. I remember making many 1/4mi passes with the O2 meter reading dead lean through the traps... and I'd driven that way 'round a track before I had the O2 hooked up... and then there was the time it was fuel-starving so badly it wouldn't even maintain 55mph, drove it spitting and bucking at full throttle most of the way home, the exhaust was so hot it burned out the Mazda exhaust manifold gasket (YES that insanely beefy gasket burned out!) but the engine didn't detonate once. (And this same engine survived dozens of detonations, too... )

Rx7dOoD

do you bye any chance have the pre 89 i think it is 6 port actuator problem? u said you were still runing lean at high R's, get a electronic 3 way valve, some hose, and a RPM activated switch tap into the oir pump which u dont have, to the inlet on the switch, then one nipple on the switch dumps and the other goes to the 6port nipple, the rpm switch makes the air pump open the actuators at what ever RPM you set it... i had this problem with my 88 because of the exhaust i went with borla cat back, high flow cat (philly cops impound yah without cats) and long headers i had made, after doing the 6port rig i dropped like .7 on the 1/4 my best time ever was a 14.6 @ 90 or 91 mph with a 1.9 60 ft on yokohama A520 205 40 17's with exhaust, K&N filter cone, home made ram/cold air intake, and a electric fan, but that was with 2 12" mtx subs, 4 6x9's, a spare tire, complete interior... i bet if i took the time to empty it out, lighten it up and all i could have seen low 14's, 2 days before i totalled it i got a NOS system with power shot and purge solenoids, and a 100 shot jet, the car was nuckin futs with spray, would grab and spin 3rd with a pepboys clutch, the next day i upped to a 125 shot went to work sprayed it real quick on the 95 comeing home, buryied the speedo and then got hit bye a drunk driver a block from my house, the car was totalled he caught me at the passenger side front tire and destroied the front end and then ran he was later caught and i got screwed royally dident even get half of what the car was worth

mazdaspeed7

Im sorry about your car man...that really sucks.

My car is a 90 GTU, and I dont have the 6 port sleeves. Not wired, completely removed, actuators, sleeves, everything. Recently, for some reason I cant explain, my car has been running richer. I put in a test connector a week or so ago, and I included the O2 sensor in that. My car had been running fine, mixture-wise lately. And its running the best it ever has.

Last wed, I had 2 races, each with someone riding with me. First was a 95 Z28(LT1) from 80-110. I started in 4th when I should have been in 3rd, and he pulled until I got into the powerband, then I started reeling him in. I didnt have enough time to pass him though, there was too much traffic. Later that night, 97 or 98 Mustang GT 5-65. I was behind him, and I had to let off at the top of 2nd so I wouldnt rear-end him. He then got off the road. I would have walked on him if we went a little higher.

mprime

Hey MSpeed7 hows the daily drivability with your 5th and 6th port sleeves pulled out ?

mazdaspeed7

The drivability is awesome, and the power is absolutely sick. When its raining, driving in 2nd gear, The tires break free any time you floor it, even at 2K rpm. If I let it get enough traction to accelerate hard, the tires still break free once I hit the major part of the powerband at 6K rpm. Thats 50 mph for me, the tires will be barely holding on before that, but once I hit that, they just light up. And my car pulls like mad to 8500 rpm.

Heres 2 threads you should look at about removign the 6 ports.
https://www.rx7club.com/vforums/show...threadid=19552
https://www.rx7club.com/vforums/show...threadid=20389

Node

iTrader: (1)

14.190 96.07 9.21 2.149 FC3S 13B Roy Baber 10/6/00 Crofton, MD

14.388 93.82 9.161 74.97 1.9652 SA22C 13B Craig Nishioka


Nice job "Roy". What mods you have, and how much HP/Torque do you have? Very nice job.

Speed Addict

Granted, no one advertises a bolt-on system. Design Energy still advertises that they do supercharging on rotary engines. When I have the funds I will just check around with shops to see if they can install the SC I want. The paxton SC seems to be very good, but I believe there are better ones available. Most Centrifugal SCs would work, but would require custom install. If you are going to spend the money, why not do it right?

Carb & SC from atkins ~$2800-3000+Install. I would guess a Centrifugal SC w/custom install would run ~$4000 [SC=2100 Install=1900 (that's my guess 1200 for parts +700 labor)]

pp13bnos

iTrader: (1)

I talked to Rob at Pineapple the other day. He says that on a car with moderate mods, 6 ports are a weak point, but not the major plug up. The lower manifold is. But anyways, he went on to say, that he's having around 100 6 pineapple racing 6 port (I call em PR6S) made hopefully by X-mas. And these will make more power than a engine with the 6 ports removed, along with better drivablilty. I allready have a set, but if 10 or so people where interested, he might do a group buy or something. CJ

Node

iTrader: (1)

A guy I met at SevenSpeed (keith) is installing a roots type supercharger, I think its from atkins.

88 vert

my car is in the shop now the original plan was just racing beat exhaust but once i got it down there i decided to go with the full exhaust from header to exhaust tip K&N filter and a 91 NA intake with new injectors well while doing the intake he found the actuators for the ports were frozen stuck solid so he recomended to just take them off and the smog pump and also the fuel rail so all i will have is a fuel line and return line and the lines to the charcoal canistor at first i had doubts but this guy is supposed to be the best around here so i said go with it im supposed to get it back the beginning of next week so ill let yall know what its like im expecting a big difference since im doing all these mods at once he said i wouldnt believe the improvement so i guess i will see when i get it back by the way is anyone else having problems posting when typing my letters just dont type write but it only happens on here oh well might be my big *** fingers well keep posting guys i have learned alot of new things about mods that can be done and the different gains of them i still want a SC kit though but dont want the one from atkins dont want a V8 carb on my rotor might start knocking and blow up just joking, Dave

mprime

Aww cool! screw it Im taking the things out just to see. I can always put them back in. Plus I know my 5th port works but Im not real sure about my 6th I think it only come open a little. I was looking for something to do today anyway:-) Also you can remove all the air pump and ACV crap to !

Ya when it's raining my 7 breaks free like that also!

I have a wide open system from my intake to my race headers and the chambered mid section then to an Apexi N1. I have been looking to get more power without laying down some cash and this may be it. :-)

I noticed you mentioned something about the MAS being really restrictive on the thread you posted and I completely agree with you the 86 has the big metal housing with the metal flap door in it and I hate that I would love to find out how to replace that.