Dan_s_young

iTrader: (1)

Ok just did a vacuum test on the fitting that is on my intake manifold, and its getting a steady 15-16" HG at idle with the 60f9's. So that seems to be in a good range. I with carb cleaner to spray around the intake, and carb to find a leak but didn't have any luck... Im running out of ideas, the car runs pretty decent with only a slight sputter with the 60f9's I would just like to get the fuel economy, down and the car running even better... Last time I drove it I got 100-150 km's on a tank of gas haha now hows that for fuel economy?

Is there any other offious places I should be looking for vacuum leaks? I have my car basically down the bare essentials. Only thing run off the intake manifold vacuum is the brake booster, and hose is not cracked or anything. And like I said all of the gaskets are new so I doubt the problem is there. I also made 100% positive that the jets idle jets ive switched between are the 55f8 and 60f9.

One thing I did notice for sure is when the car was maybe at 1200 rpms, I opened up the (cold start assist lever?) manually and the header seemed to slowly go back to a NON-cherry red colour. Its offious the car is running lean, I just can't believe it won't run at all once I change the idle jets...

perfect_circle

um, what do the numbers represent on the idle jets. i hav a stock port 12a and the idle jet is a 65 f9 , i have f11 e-tubes, 180 fuels with 180 air correctors.

juantii

Hello Robert, I have a problem with a 1988 rx-7 turboii with stock injection and turbo, the problem is that the car stumbles(hesitates) bounces back and forth as if it wants to regain power just after it starts to stumble, I hope you get the picture, it does this at 6500rpms. with the stock boost(6psi.) but I just recently installed an HKS fuel cut defencer and the boost is now at 12psi., but the stumbles now begin at 5000rpms and it goes back and forth until it reaches 6000rpms, but it does not get any farther than this on the rpms.
please reply with some ideas on what should fix this problem

thanks in advance

Michael_Rudy

Hey Robert! Well i have been trying to find out what size turbo i should use on my Peripheral Port 12a. The housings are MFR housings porting remains stock on the intake, and that ehaust port has been opened up a fair bit. The goal is to get around 10 hp per cubic inch, so i am shooting for around 700hp. So running around 25-27 psi when racing, and 16-18 psi on the street. What would you suggest? I would like to keep the revs under 11,000 so it it started to make boost around 7,000 that would be fine.

Also is this turbo to large? http://cgi.ebay.com/ebaymotors/ws/eB...MEWA%3AIT&rd=1

Thanks, Mike

680RWHP12A

sounds like a fun project.. 700 hp is achievable, but not a simple task
that turbo will not wok, thats a straight diesel turbo, you will need a custom b/b unit to work properly... pm sent

sand121

iTrader: (3)

Hello, I've got a question, what size venturis on a mikuni 44phh would work best for a streetported 12a with a S4 turbo running around 8-10 lbs of boost. Right now I've got 39mm and I think that will be a little too big. I can get 34mm and 37mm. Also you wouldn't happen to know what would be a good starting point for jetting? One more question about the turbo. The are four openings in the center of the turbo I know the ones on the top and the bottom are for oil, but what are the ones on the sides for? coolant?

Thanks in advance
Caleb

680RWHP12A

go with the 34 venturies(fror lots of low end, or bigger ones foor more top end, depending on what your looking for) with 180 to 190 fuel jets that should run good.. the other holes on the turbo are for water,(the ones on the sides) not really nessisary, just let the car cool down after hauling *** before you shut it off :O

perfect_circle

...

TimsR1

Please help.

What exactly is needed to connect a wideband o2 sensor to a datalogit and powerFC?

Is it necassary to purchase a full wideband controller setup or just the Bosch wideband itself?

The datalogit shows info within the monitoring part for air fuel ratio, where is that info derived from?

If I'm posting this question in the incorrect section please refer me to the correct placement for these questions.

KnoxSe7eN

680RWHP12A PM sent

Thanks for the help

drew109

i have a 1987 rx-7 and its havin some electrical problems. the car was having problems and i took it to a mechanic who told me there was a bay fire. he said he fixed everything up but apparently he didnt. there is a fuse under the hood, a 30amp fuse that blows almost right away whenever i turn the key in the on position. im not sure what the fuse is for but it says EGI COMP. on it. i couldnt find anywhere that told me what that was or what would be causing it to blow. any help on this would be greatly appreciated. thanks. drew.

680RWHP12A

the problem is in the engine wiring harness, where, is beyond me.... i would need the car to diagnose exactly where the wiring fault is...
the easiest way to fix the car would be to replace the engine wiring harness all together, since your mechanic cant fix the existing harness..

680RWHP12A

its a pretty lengthy explination, i will send you an e mail this week

here is the short version

the big # , 55, 65 etc is the jet size,(hole on the bottom) the f# like f4,f5,f6 etc. its the air bleed hole(smaller hole on the side of the jet), this determines how weak or strong the signal to the larger hole(the jet size)is...
so a 55f9 will be richer than a 55f8.. a 65f6 will be leaner than a 55f9.. make sense? its basically a way to fine tune your idle circut and make the transition to the main circut as smooth as possible..

KnoxSe7eN

I sent you a pm but decided to post it here. You can disregard the pm now lol.

What blow thru carb and manifold would you recommend for a large street ported 87 13b(s4 turbo 4 port in a 87 Turbo 2 FC3S). I am shooting for 400-600rwhp. Anything in that area I will be happy with.

I have heard good things about Holley's but wanted your opinion.


Thanks for your help its appreciated.

KamakazieX

ive been looking everywhere for some help getting the right jetting info for a 45 dcoe on a 13b 6 port with a pierce manifold and rb true dual setup. i sent a pm.

wReX

iTrader: (6)

Well first of all, thank you Rotary Shack for starting this tread to help answer questions. I have read every single page and picked up quite a bit of knowledge.

My '93 has been running flawlessly for the past year; I had almost started to wonder why nothing was breaking, lol. Well, jinx, I think it's finally my turn to ask a question.

The car:
'93 5spd
Race port
non-seq twins(14psi)
Power FC(Tuned by Steve Kan)
850cc/1300cc
supra pump
MSD 6a on leading
#9 plugs
Profec B
intake/full exhaust/pullies/greddy smic

Scenario: Wanted to get my A/C working(has never blew cold air since I purchased the car). I wasn't having the Power FC related A/C issues so started to look the the AC system itself. Freon level was still good so I started to look over everything and noticed that the A/C Compressor wire was unplugged so I plugged it back in. AC still didn’t kick on so we tried to use a jumper wire to hot wire the compressor straight to the battery. This seemed to free up the compressor clutch and it started blowing nice freezing R12 air. In the process of removing the jumper wire though my friend arc'ed the **** out of it when he accidentally touched the jumper to the intake piping. I scolded him, lol but we shrugged it off and plugged the compressor wire back in. The A/C started to work but was acting really funky, ie compressor would stay on at idle but as soon as I put it in gear and took off the compressor would shut off. Watching the Power FC on the 'sensor' screen I could see the AC light keep coming on an off.

That is not the problem though, just what we did leading up to it. We finally gave up on the AC, I was set on taking the car to a local rx7 guru to take a look at to see if he could get the AC going as I had to leave out of town that night. I unplugged the compressor wire to leave it how everything was.

The problem: When I first started the car after playing with the AC I noticed it seemed to have an audibly different exhaust sound/note/pitch, it seemed 'deeper' in tone than normal, idle was very smooth though. Also, as worthless as it may be, the 2-wire Autometer A/F ratio gauge that’s in the car was acting oddly. Before it would just idle and the AF gauge stayed solid in the green(rich), maybe moving around slightly but not much. Now it is all over the place at idle bouncing from rich down to lean and back and fourth. Took the car out for a spin and noticed it was hesitating/bucking while say cruising at 2k RPM in 2nd gear down the road. I gave it a little bit of gas to see if it would even make any boost, from a stop I started moving with around 30% throttle... at around 2500rpm the boost was already instantly shooting up to 14+psi on the boost gauge so I let off. The car was not accelerating at all though.

For some reason I am thinking the Power FC has lost it's tuning somehow and resorted back to a base map or something. Maybe it has just gone into some kind of limp mode with really retarded timing or something. My PFC knowledge is severely lacking but I flipped through a couple of the screens and noticed minor things like my preset idle RPMs were changed, use to have it at 950rpm, now it's 1000rpm. The injector settings are still showing the 850 primary and 1300 secondary though. PIM votage is 'normal'. Other than that I'm at a loss with what to try now.

Any tips? Thanks in advance for any help. Take care. -Mike

BlownPickl

iTrader: (1)

I want a side mounted 13b to be front mounted. I have tried a 12A cover and that does not work. I believe it is the oil pump that interferes. Does a GSL-SE cover have the clearance for a newer 13B?

Final question! If I buy a $100 GSL-SE cover can I reuse it on newer 13B motors?

REV_HARD

wHAT TYPE OF POWER SEEERING FLUID TO USE IN 85 GSL-SE PUMP.

680RWHP12A

any power steering fluid will work fine

Ballin_is_a_Habit

what is best size exhaust to get power gains out of an na fc

2 1/4 ? this is what i have heard recently picked up some exhaust but it is clearly for a turbo

southernrunner

I have a s5 na engine and it doesnt have exhaust sleeves but I have other housings. How do I take the sleeves and and put them in my engine?

perfect_circle

ok, well after weve talked about the chokes. and the jetting, what do you propose i do to fix the stumble??

680RWHP12A

drill out the roll pins on either side of the rotorhousing (next to the exhaust port on either side) and the sleeves will fall out.. you will need to install new roll pins ...

680RWHP12A

i dont know, i can only do so much without tuning the car myself...
you can thank cp for your wonderfull carb..

680RWHP12A

for the best power gains n/a, i would run dual 2" pipes frrom the header to the rear wher its collected into one 3" pipe then into a straight through muffler...