1981 freshly rebuilt Streetported Nikki carb Turbo 12A
 

I rebuilt my 12A engine with fresh internals and drove it for about a 1ooo miles, three days ago i installed my turbo and my engine has been acting really weird !!!



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do you have the carb setup for a turbo or is it still in the N/A setup?

I would bet that would be why its running funny, especially if you havent supplied extra fuel for the extra air the turbo is now pumping.

:iwstupid: you can't just whack a turbo on a carby and expect it to even run, let alone get better results.

If it does end up working for you I'd be interested in what mods you did to the Nikki to handle the boost.

it's supposed to be a boost prepped nikki carb from racing beat ! how could i know ?

Here's the video, listen to the engine !!! it works amazingly good in first and 2nd.

http://vids.myspace.com/index.cfm?fu...ease=104441061

HERE'S the Video=====> http://www.facebook.com/v/566690795223

Sounds like either fuel or ignition. What have you done to both those systems to prepare them for boost? We need more info about you setup.

I did a lot of research on this subject the nikki carb is tuff to boost prep.

it simply cant put enough fuel to boost, unless you re jet it and pump more fuel to it.

If you say it works well in first and second is that with full RPM band or just to a certan RPM if its a fuel issue you tell reall easy by the RPM band the more RPM's the more finiky it gets the it fuel delivery if its at low RPM then it may be geting to much fuel at low RPM and cause bogging.

We need a lot more info befor we can really help

1. was the carb boost prepped with bigger jets and air tight seals
2. was the ignition system upgraded like better coils or 2nd gen direct ignition
3. was th fuel pump upgraded to deliver more fuel for the consumption
4. how much boost are you runing doea it have a controller
5. did you pressure test the turbo to carb hose's to make sure your not leaking?
a. did you rubber gasket the intake to carb area to make sure your not leaking there?
( i noticed you have the stock intake to carb plate with vacume lines are they all blocked off and again did you rubber gasket them?
6. if you remove the turbo and run engine doese the problem still happen?
7. what kind of exhaust system are you runing?
I would start there if you can get us more info we can help more

sounds to me like fuel or vacume/pressure leak res

1. was the carb boost prepped with bigger jets and air tight seals - the person I bought it from said it was.
2. was the ignition system upgraded like better coils or 2nd gen direct ignition (it's all stock)
3. was th fuel pump upgraded to deliver more fuel for the consumption. (It's STOCK NOW but I did put the pump that came with kit and I connected it to the fpr incorrectly and it leaks through the carb !
4. how much boost are you runing doea it have a controller. (Unknown boost, turbo had no shaft play)
5. did you pressure test the turbo to carb hose's to make sure your not leaking? (No, but I am sure I would notice that)
a. did you rubber gasket the intake to carb area to make sure your not leaking there? (No)
( i noticed you have the stock intake to carb plate with vacume lines are they all blocked off and again did you rubber gasket them? (I think they are blocked and no I didn't rubber seal them)
6. if you remove the turbo and run engine doese the problem still happen? (No - in third 4th and 5th under full throtle it kind of hesitates !)
7. what kind of exhaust system are you runing? ( NOTHING AFTER DOWN PIPE)

1. do you trust this person do they have a reputation, so far i have heard of only 2guys who can boost prep a nikki carb atkins rotary and queen street racing from AU

2. get some blaster 2 coils you should do this anyway better for the engine turbo or not.

3. if fuel leaks through the carb it IS NOT boost prepped the correct seals for this preperation would hold the extra fuel pressure and send it right back to the tank via return

4. GET A BOOST CONTROLLER

5.the smallest pin hole will effect your boosting very much so with a rotary needing to be sealed 100% no leaks of any kind past what pressure your running so if you boost 6psi it should hold pressure to 8 psi without befor it leaks any air.

5A.VERY IMPORTANT: you must rubber gasket ALL the intake parts to preserve the boost pressure.VERY IMPORTANT

6. you know its not the engine then it must be associated with the boost !!!! FUEL or BOOST PRESSURE so that narrows it down.

7 you good on the down pipe i only asked because it could have been a clogged CAT

I would assume its the carb you should run a 55LPS fuel pump to assure your getting enough at the carb its cheap i think i paid 198.00

here is what you do buy this intake it a holley intake for 79-85 12a street port it bolts on and looks nice Racingbeat has it $262.00 part number 16464

http://www.racingbeat.com/FRmazda1.htm

Then buy this carb.ask them to have a holley !!!!IMPORTANT!!!!550 or 600 cfm blow through!!!! it ranges from $700.00 to $900.00

http://www.houseofboost.com/store/su.../prod_801.html

for just over $1,000 you could boost your 12a streetport to about 10 lbs
Note with this set up you will shoot flames like a DEMON from hell make sure you dont have strick local laws.

anyone can buy this set up and strap it to thier engines and have a turbo 12A its just not as cheap when you have to buy the rest of the junk


if there is anything else just ask.
I myself went with a 13b T2 12a after that much money just didnt put down enough power unless its a bridgeport

racing beat does not sell boost prepped carbs i dont think they ever have. i hate to say it but i think you got ripped off!

we should get this archived so people can search this info this is the ump teenth time i have had to post this info!

Thanks so much for all your help. I will post more pictures and videos of the trouble shooting. I know for a fact that the reason the carb leaked was because i did not have the return line connected to the FPR !!!!!!! does that make sense ?

As for the person i bought it from, he had issues with this turbo setup and switched to Supercharging his 12a????

If you need to know any info on building a 12A blowthrough with the Nikki carb, just check my build thread when I was running a boosted 12A. I was making about 250 RWHP at 15 psi. Car ran great. Drove great. Just have to know what your doing :D

My build thread https://www.rx7club.com/build-threads-293/project-updates-553481/

Will do, thanks.

I guess I will give rexy a break until I have enough time and $,$$$

WOW, that is so awesome... I love the little Nikki and to see one with a turbo on it.. omg :shocking:

you can trust Bad83 with any nikki blowthrough advice, he's been down this road on his own and I have heard from others he helped. Excellent resource!

Where's the fuel pressure reg, I don't see one under the hood. You need a reg with a vacuum/pressure port to increase fuel pressure with boost. 6psi fuel pressure and 8psi boost means the boost overpowers the fuel and shoots it back out the carb, fuel pressure needs to be 5psi higher than boost pressure.

The stock ignition can work, you just need NGK B8EG plugs gaped to .010 and they'll still foul out eventually.

Make sure all extra vacuum ports are blocked off and put hose clamps on EVERYTHING or they will blow off.

Thanks for the kind words.

Actually the base fuel pressure the Nikki stays the same as factory. 3.5 psi. You need a Walbro 255 fuel pump. It can be placed in the factory location. You will need an Aeromotive rising rate fuel regulator (1to1 ratio) that will need it's own seperate return line to the fuel tank. I just drill and tap the top of the fuel tank for the regulator return. The dizzy needs to modded and locked at 10 degrees with a 10 degree split for the trailing. There is quite a few steps to modding a Nikki for blowthrough.

Just a piece of advice. INTERCOOLER......

I will have to give the mallory 4309 fpr i have a try as well as the Bad ass fuel pump
{ i have that made my pipes swell like a balloon} before i buy anything else, i have a 1 month old babe and two year old to tend to, not to mention my other half that come first on the spending's and i don't mean rexy.

In those pictures i took the fpr off to trouble shoot !!! and then i drove home carefully BURNING OUT in 1st and 2nd :) .....

Does any one have any used turbo parts that i need like the intake and carb ?

What about demon carbs ?

I really don't understand some people..... you spend all that money to rebuild your engine and then you're going to blow it up by slapping a turbo on and not doing any homework before hand. I watched the video and can tell you that 2 things are going wrong.... your carb is NOT boost prepped.... and you are starving the engine of fuel.

Lean Mixture+Boost=Detonation...... so long apex seals.

I guess if you really want to go through the trouble of sourcing a decent set of 12a housings when you grenade your apex seals into the housing wall, then keep doing what you're doing.

Demon carbs are great but not boosted.

Trust me man you asked for help i gave it to you, IF YOU WANT IT DONE RIGHT AND SAFE LISTEN TO THE PEOPLE WHO HAVE BEEN DOWN THIS ROAD!!!!

as for Wides comment, its his car if he wants to blow it up he can do just that.

Thanks for your concern wide, no worries i am not driving the car at all, in fact i stopped it in my garage until i obtain all the mentioned above parts. where can i buy the stainless steel braided lines for the fuel lines ? and does any one know how long it is from the fuel tank to the where the fuel pressure regulator should be ?

tape measure buddy lol