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After staying up for two nights straight I've decided I'm going to finally finish the turbo project I dreamt up years ago.
my plans are basically to copy jeff20b's setup.
-stockport 12a
-sterling nikki(we'll get to this)
-s5 turbo
-stock psi
-custom manifold(2" sch 40 els mild steel tube)
-3' rb downpipe
-gonna hang on to the mindtrain as long as I can(2.5in)
-AEM UEGO
-no I/c yet
-walbro 255
-Mallory 4309
-1/2 fuel return?
-3/8 feed? or 5/16?
I have everything but the turbo manifold. the aem, carb hat, and jets, lots and lots of jets.
a few questions. these are essentially aimed directly at Jeff20B but I figured I'd do it in a public forum so if I can learn, maybe someone else can.
-any reason not to use a sterling? I was thinking of buying a spare and hogging/boost prepping it via jeff20b's layout as best I can. then if that works. maybe duplicating it on my sterling. from what I understand its throttle plates are machined down but the AP mod is too long(from what I've gleaned)
-how far back should the 02 sensor be? the bung is only a few inches behind the turbo.
-do you think ill be able to get the pressure low enough with the Mallory on the walbro if run a 1/2 inch return line?
(I ask because I know that people have had difficulty with them. but I purchased them years ago and would prefer not to have to make another unnecessary purchase.)
-should I increase the size of the pick up inside of the tank? or modify that in anyway? I'd like to have as little rubber as possible in the fuel system(potential e-85 down the road, but now as I'm saying that, I'm concered about the floats and rubber bits in the carb..)
anyway thanks everyone. hopefully I'll have a build thread started soon.
Stockport 12A. That's a good place to start. I assume your intake manifold is ready for boost. No rat's nest. Semi-locked dizzy. Light steel or stock flywheel. Avoid aluminum flywheels with turbos. A waterpump with water fittings for the turbo, if you chose to allow it to be water cooled. Some of us, including me and Jobro, don't.
Sterling. As far as I know, no Sterling carb has ever worked with boost. Carl and Sterling tried their best about ten years ago and it failed miserably. But there's hope! Because a Sterling carb is basically like any other hogged out Nikki, if you follow a basic air bleed and jet re-think, for lack of a better term, it will work. I know it will. I'll cover the specifics later.
S5 turbo. It's all I've used up to this point. Just tested a retro-fitted late model S4 CHRA into S5 exhaust housing yesterday and it worked perfectly.
Stock psi is 5.5 for the S4 and S5 wastegate spring. The S5 had a solenoid that would allow boost to rise to 9 psi or something like that. No need to worry about that because with a 3" DP it might creep to 7psi like mine does. Up next I'm going to try one of those cheap ball and spring NXS manual boost controllers from eBay. I just swapped some better sized 1/4" brass fittings into it yesterday. They all come with sharp barb 3/16" fittings. I'll swap it in when I'm done testing the S4 into S5 turbo and go back to my other S5 turbo.
Custom manifold? Do you really need that? I got away with a 7/16" steel spacer and the stock manifold with a set of FD studs swapped in. Of course it all fits really tightly and required a lot of rotor head thinking time. It was less straight forward than a custom tubular manifold, but also less work in the end.
3" RB downpipe will spool the turbo faster than a 2.5" DP. Watch for boost creep.
The mindtrain can work because it is 2.5". It is ok to run a 3" DP into a 2.5" exhaust according to j9fd3s. I plan on doing something like this eventually.
AEM UEGO is what I have; the 4100 and 4110 versions.
no I/C yet either
walbro 255 might work if the send is squeezed down from the walbro's 3/8" outlet into a 5/16" line leading up to the fpr. But I still recommend an MSD 2225. My walbro didn't go below 5psi when I had it with the wrong size send and return lines. The MSD worked, just barely, at 2.5 to 2.75psi minimum. Then I corrected the lines and now the fpr reads as low as 1.25psi. I only have a 3/8" return line under the car that squeezes down to 5/16" when it goes into the tank.
Mallory 4309 is correct
1/2 fuel return lime? Why not decide to swap to the correct fuel pump? 1/2" diameter line contains a lot of fuel that needs to go back to the tank quickly. I'd rather follow Mallory's instructions and go 5/16" send and 3/8" return.
My GSL-SE tank has a 1/2" send line from the tank, then I contract it down to 3/8" with a filter before it enters the MSD pump. The MSD has a 3/8" inlet and a 5/16" outlet making it perfect for our cars.
You might not need lots of jets. I would also avoid the crappy holley air bleeds Sterling would use as jets, if you can help it. The only real practical solution is to get a set of micro drill bits and start drilling your own stock jets if you have an adequate supply like I did. Lots of old 92 jets allowed for some test drills. I eventually settled on... oh wait I'll get to tuning later.
I can't think of a reason not to use a Sterling, but only if you are willing to undo all of his jetting and air bleeds, plus some other changes. The AP mod the way Sterling does it, for example, is wrong. It will need correcting, but the length of the extension is not at fault. It is the size of holes he drilled. No one needs .050" holes in the nozzle, not even me! And especially not a stock port 12A. I use a 118 drill bit or .0465" but a metric micro drill bit around 118 will work. My set has a 119 in it (1.19mm). But you also need to understand that Sterling needed huge drileld holes because his jetting and air bleed tuning was based on Yaw's methodology, which is incompatible with boost tuning. For boost since yo have abundant air, you are required to use very small air bleeds and with smaller air bleeds, you now need smaller fuel jets. Seems wroing with boost, right? Not really seeing as the increased air makes the carb work essentially better, or at least it's different enough that smaller everything is required. I'll post a best guess bench tune for turbo use with a Sterling at the end of this post.
They're machined throttle shafts, not plates, but as long as the butterflies seal well when closed, mainly the secondaries, it should still work. Oh, avoid the flip-o-matic. It is a stupid mod that needs to be undone. What it causes is the secondaries to open over 100% which hurts power. Take a look for yourself if you have the flipant mod and put it back to stock. Then weld the linkage instead. Or at least wire tie it if you need it to be reversible. Or at least the one I saw on a god-awful SR Nikki I corrected as much as possible over the weekend,. What a terrible carb. Everything that could be done wrong to a carb, was done wrong to this carb. I feel sorry for all the sap suckers who bought damaged carbs from that idiot. At least now it can finally idle on its own. Bent shaft and all.
My O2 sensor is under the car. I don't believe in putting it close to the turbo.
You need an MSD fuel pump. I bought a walbro years ago and it was way too much pressure so I bit the bullet and got an MSD. I've been happy ever since. Karack said the walbros have something like 60psi base pressure. Who needs that much?
I would avoid E85 because I don't understand it, and I don't want to ruin fuel system components. Plus I don't know of any stations around here that even carry the stuff. Plus don't you need to fatten up everything just to run it? Like a super rich tune if pump gas = fine for E85? I guess I don't understand. Heck I get 92 octane and ran 13 accidentally during tuning on the wideband and it didn't pop my engine so I could probably get away with 89 octane running 11 AFRs. I guess I don't see a point to E85. Maybe you can educate me.
This is your build thread, right? Maybe it should be. You already got the ball rolling.
Ok, my best guess bench tune for boost on a Sterling carb with 22mm venturis will want:
primary slow short bleed: drilled 118
primary slow long bleed: stock 46
primary main air bleed: stock 70 or in your case H27 (H=Holley air bleed) .68mm
primary fuel jet: H45 or 115 or 1.15mm
secondary fuel jet: H55 or 140 or 1.40mm
secondary main air bleed: stock 92 jet or .036" or H36 (any nearby size will do)
secondary slow long bleed: solder filled
secondary slow short bleed: solder filled
Of course this is just a bench tune. Any actual tuning must be carried out in a careful mindful way, but this should be enough to get your Sterling up and running with boost. Oh if only we all had this information ten years ago.
pro-tips:
•Take out the nickel plated 60s and drill to 118 and swap into the primary side.
•Take out the brass 170s and fill with solder, then swap into the secondary side.
•fill the secondary long slow bleeds with solder. Be careful because it likes to flow right out of the little holes near the bottom.
•DO NOT TOUCH the primary long slow bleeds. The tiny 46 hole at the bottom and thus idle quality is insanely sensitive to its size. I've found differences in stock ones cause an idle tune to go from 11 on the wideband to 13 just by changing these from one carb to another. And these are factory! Do not change (enlarge) the size of the tiny hole at the bottom. If you do I'll come to your house. And you don't want that. Er I mean the carb will never idle right again.
first of all let me say thank you so very much for being such a gracious human being with all of your knowledge. If I had tickets to heaven, I'd give ya one. Now I'll get off my knees..
-intake manifld should be good. No rats nest. I have a fully locked dizzy. But im going to opt for your partial lock dizzy.
- no coolant to the turbo. Oil feed is coming fron the sending block. Gonna tap the return into the front cover.
- I did not anticipate that the Sterling carb would work out of the box(with boost) but I figured with your modifications it might be okay as long as there isnt anything I'm overlooking. I did forget that sterling has the carb setup for Holley jets (just the air bleed right?). Its been re-tapped correct? Unless some other jets can use holley threads i dont see how not to use holley bleeds.
- do I really need the tubular exhaust manifold? The answer is no. but this is my moby dick. I have a series 5 turbo manifold and the 1/4" spacer/header flange that I was going to use. But i just dont like it. It would be the simplest for sure. But i am compelled. I may fail and revert to a modded stock manifold. But i really like how tubular manifolds can relocate the turbo.
-eugo 4110 it is! (its got a bigger number)
-msd pump it is 5/16" feed, 3/8" return. (I thought that a 1/2" return would evacuate enough fuel to allow the mallory to controll it. And I have some already laying around. I will concede however)
-I've read through both of your boost prepping threads a handful of times. I have some knowledge about how carburetors work, I've rebuilt them and worked on them. But I feel like I would get less lost if I had a carburetor in front of me as I was reading what you were typing. that's why I was considering starting with a blank canvas of a stock Nikki and following your steps so I might have a more intimate knowledge of it more in the realm of yours( which would ideally pay off when it comes time to tune)
-I will have to weld my 02 bung closed and relocate that.
- I really doubt I could teach you anything about e85 I just know that it runs a higher octane(like over 100 but dont quote me) and is corrosive to standard rubber parts(alcohol/meth content). I I know it's gasoline with methanol added and that people use meth injection on top of a high powered turbo system when it starts to run on the wragged edge because it cools the charge and increases the octane.
[conjecture]
I was thinking once you got a baseline tune going and then you could crank the boost up and then once the air fuel ratio started to lean out if you went to e85 it would bring them to a safer level because it's a higher octane [/conjecture]
We have an e-85 station in Marshall, MI. A town with horses and buggies still.
Its all along I-94 coming out of detroit! Gotta test them new cars.
-This can totally be my build thread. If perhaps a mod could so kindly move it?
-I'm going to have to print off all of your posts and invest in a new soldering iron and get to work.
just having a place to start when it comes to tuning it is immensely helpful. I'm sure this isn't the last Nikki related question you'll hear from me. but I'll do my damndest to do the research first and not just ask you nooby noob questions.
- I won't touch the primary long slow bleeds, but if I do I'm going to buy some beer first so you won't be totally disappointed when you get here. (thanks for the good chuckle I got from that too!)
Yep, semi-locked is the right way to go. It is at 0 degrees at idle and then advances to only 10 or 12 degrees. It starts and runs and drives way better when it can idle at the timing it likes best, which is zero degrees. Then it advances like it's supposed to but can't go above a set limit. I've not found any issues while in vacuum with a semi-locked dizzy.
I used an RB blue anodized pressure and temp sender for the turbo oil feed. The return line fitting was added to the front cover before the oil pan went on. The plan was to always turbo this engine when I built it in early '13. Took a year to get the turbo on it. Now two years later it's doing great!
Only the air bleeds are machined to accept Holley air bleeds. The fuel jet locations are still stock. The standard thread pitch will fit in the metric threaded holes. My advice is to try it both ways in the jet holes. I say this becasue I have limited expereince with holley air bleeds used as jets. I don't like them because the shape isn't as funnel-like as stock jets so they won't be as effiecient at high flow rates. It could change what you see in the wideband slightly. I saw a different of 12.something with stock jets vs 13.something with some old school shallow funnel jets from a 74 hitachi carb. The Holley aier bleeds are somewhere in between in their funnel size/shape. Both were drilled with the same micro drill bit at 1.30mm I believe. Used as secondaries. This is why I recommend 1.40mm as a starting point. Then go slightly smaller until your wideband shows 11.something which is ideal for boost. 11.5 to be exact? Maybe. Do some research to be sure.
I may want to buy your S5 manifold if you don't end up using it. I need one. Or will need one soon.
4110 is the newer one with the updated connector and 6 wires. I don't like it as much as the older 5 wire version. However the newer one is faster I think.
Yeah, I would just go with 5/16" send and 3/8" return. Seems like less headaches down the road. I wish I would have known sooner.
You coud start with a blank canvas. That's what I did. I hogged out and boost prepped four 81-85 Nikkis in a row last year. Each one was slightly improved. When an issue would pop up such as a leaky baseplate gasket, because the new ones in rebuild kits are way too thin for some reason, I had to start making my own out of the thick blue paper that comes in gasket paper kits from the auto parts store. Or I could double up or tripple up the thin gaskets from the kits. I like th eseingle thick blue paper better. Plus you can tell at a glance that the carb is boost prepped.
However if you start with the Sterling, it is already half way boost prepped right out of the box. Of course this assumes it's not one of his later carbs that were notorious for running badly due to increasingly sloppy work due to ever increasing demand and his one man operation. Well, Carl was involved but Sterling took most of the blame whenever he sold a bad carb. Things like crappy aftermarket seats would cause major unsolveable flooding problems, for example.
When you prep your spare blank slate Nikki, leave the stock seats alone. It's ok to swap in new needles, but do not install the badly machined new seats from the rebuild kit.
Pro tip: grab the OEM seat with a vice grip gently but firmly. Don't crush it! Give it a single smack with a hammer and it should loosen. This lets you unscrew it and remove the little filter strainer on the inside tip. If it's not there on 81-82 carbs, check up inside the air horn. You will notice the aluminum crush washers are VERY crushed from the factory. It's like they use way too much torque when they install them. Replace the crush washer with new ones from the kit and install the original seats using a wide screwdriver. Don't overtighten because it can strip the slot. Same goes for trying to loosen the stock factory installed seats. I speak from experience.
One difference to be aware of when comparing a Sterling carb to a stock one, is the size of the venturis. Stock will be 20mm and Sterling will be lathed out to 22mm. Supposedly Sterling's cuts were efficient but I gotta say a recent teardown of the worst Nikki in the world, built by that CobraStngSVT guy back in '11, who copied everthing Sterling did, but in such an incompetent way it;s way beyond laughable at this point, revealed cut venturis that were so far are of whack they didn't draw enough vacuum for the carb to even run on them. Something like 9mm below the bottom of the booster which is completely wrong. The only way it ran was from the accel pump that I had to redo from his crappy over-drilled one, following Sterling's advice. Uhg. I used some of Sterling's recommended techniques as well as some I pioneered myself, and the accel pump is great. Anyway whatever you do, if you hog out the venturis of your stock carb, cut from the bottom up. Don't change or modify the upper part of the venturi above the narrowest point. It has a slight curved shape there for a reason. I leave that part alone on my venturis and only open them up until I get to 24mm or 25mm so they work on a 13B. There's way too much to type but you get the basics.
I'm running a AN-6 return line, I think that converts to 3/8", and I don't have any issues returning fuel to the tank. I welded a plate on the tank to shoot the fuel strait back into it. I can get any pressure from 1-14 #s out of my Mallory. BUT your e-85 thing kinda negates doing this.
I'm using the big factory hard line (I think its 3/8) as my send line; backed by the wholly obnoxious Comp140 fuel pump.
But that's about as much info as I have on the "Jeff turbo" cause that's as far as I've gotten. Aside from semi-locking my distributer which is a hella easy task.
because we have decided that this is going to be my build thread I'm going to update it with other non 12a turbo stuff well sorta. I just picked up a set of virtually new rims and tires with adapters for a reat deal from an awesome seller (thanks XLNDRVR) my raw steel came in for the tubular manifold (just need to mill the s5 turbo flange.) and I just ordered a set of camber plates and coilovers.(thanks highnitro12187)
I did find out though that in order to use my Tokico iluminas on the re speed camber plates that they need to be machined down just below the threads in order to fit into the camber plates.
my understanding is this that because the suspension is so much lower that you're losing a bit of travel with the shocks themselves because they're nearly fully compressed.
so let's say I've already got them in the lathe then I just machine off like an inch and a half or two from the end and then rethread the end. would this increase the ride quality and keep the shock from bottoming out without changing the dynamic of the shocked too much?
also this is another brains storm i had. I was thinking about using the stock blue air cleaner and sealing it off at the front and all the ports on the bottom and around it and then using the 1& 1/2-2" inlet at the bottom that's for the old emmissions system as the inlet. Nice and discrete and retro. Terrible idea?
Edit: also here's another tip for cleaning carbs Jeff I noticed you were using some really corrosive carb cleaner I learned from the bike guys they all use Pine Sol I guess it cleans just as good without destroying the rubber bits. and it smells way better.
I also forgot the pictures.
Last edited by perfect_circle; 05-30-15 at 02:37 PM.
^^^ YOU BOUGHT MY WHEELS.... GRRR What offset are they?
I thought about that stock air cleaner lid idea. I tried sealing all the holes, but like Admiral Ackbar said, "THERES TOO MANY OF THEM!!!". And the charcoal canister (if your lid has one) is a major flow restriction. I had a plan to use a TBI intake pipe from a dodge Dakota and hide it inside of the stock lid, but I ended up going with the Nikki and droping the edelbrock. So that plan died.
I cut up a spare lid and I plan on using the lip as either a place to clamp on a 90 degree elbow from an intercooler piping kit or welding a hat on there like Jeff did.
^^^ YOU BOUGHT MY WHEELS.... GRRR What offset are they?
I thought about that stock air cleaner lid idea. I tried sealing all the holes, but like Admiral Ackbar said, "THERES TOO MANY OF THEM!!!". And the charcoal canister (if your lid has one) is a major flow restriction. I had a plan to use a TBI intake pipe from a dodge Dakota and hide it inside of the stock lid, but I ended up going with the Nikki and droping the edelbrock. So that plan died.
I cut up a spare lid and I plan on using the lip as either a place to clamp on a 90 degree elbow from an intercooler piping kit or welding a hat on there like Jeff did.
I may switch rims down the road. You can have first dibs. Im not guaranteeing there will be rubber left though
I saw your thread now that you say that that's probably where my inspiration came from. when trying to seal it were you welding it?
Originally Posted by ray green
I totally agree with all of the above. Nice wheels!
With me or with the too many holes? And thanks!
Last edited by perfect_circle; 05-30-15 at 09:39 PM.
A couple of corrections. Use a propane torch, not a soldering iron. You'll be there all day.
What corrosive carb cleaner? I used the chemdip stuff on one carb. The parts all came out looking brand new. No damage to any metal. Makes me think I should have soaked them all, but it's a lot of work to deal with that stuff and it smells wonderful. The little nylon things under where the boosters sit are just fine after their soak.
A couple of corrections. Use a propane torch, not a soldering iron. You'll be there all day.
What corrosive carb cleaner? I used the chemdip stuff on one carb. The parts all came out looking brand new. No damage to any metal. Makes me think I should have soaked them all, but it's a lot of work to deal with that stuff and it smells wonderful. The little nylon things under where the boosters sit are just fine after their soak.
Propabe torch done. I was told the chemdip and other chemical carb cleaners can break down the rubber o-rings. I dont know about the nylon stuffs. I do know that pinesol cleaned my suzukis mikunis very effectively.
I may switch rims down the road. You can have first dibs. Im not guaranteeing there will be rubber left though
I saw your thread now that you say that that's probably where my inspiration came from. when trying to seal it were you welding it?
I tried brazing them with a propo torch, but the gaps in some areas are so large. And I tried crimping but it looked shoddy. Then I started to just plug them with goobers, and I'm not the goober type of guy so I threw the idea out.
If you have acces to a TIG and a good certified welder (or if you are a certified welder) you can probably stick it all together, But for me it seemed illogical. That metal its made of is SUPER thin and difficult not to burn through.
I think a header pipe might be too thin. I didnt want it to crack. In my research aaron cake reccomended searching for weld els sch 40(schedule 40(wall thickness) which is about middle of the road between 10 and 70. There are several vendors were reccomened (mcmaster carr, mcjunkin redmen there are more but i dont recall.) but i found mine on ebay for 25$ for the 5 90° bends at 2". I still need a straight portion.
i don't know anything about nikki/turbo setups be we recently switched the race car to E85.
it works just like gasoline. it is higher octane, plus there is some "heat of evaporation" going on, so even on a non turbo miata, we gained 10hp, which is a lot on that car. turbo would probably be in the same boat, but you should gain some safety margin too, which is nice.
we changed the fuel filter, but left the fuel system as is, although its a newer car (99), and we run a lot of fuel through it.
the only sticking point, is that you need more volume with E85, the miata actually has enough headroom that we didn't need to change any hardware, just a remap. the carb will need to deliver more fuel all the time, and that might be hard with the nikki
we also found that it didn't want any more timing than what we were already running, and it was happy at about same lambda number too, so we we not really missing any HP on gasoline.
since E85 varies between E85 and like E65, i think i'd tune it at like E65, i think that would give the most margin
Now that j9fd3s explained it, I bet I could use E85 no problem.
I run very small jets in my Nikki on pump gas with small air bleeds and boost. Sounds easy to just throw in some bigger ones.
As for fuel delivery volume, I already get plenty with pump gas. I think it would work ok with E85 too.
Your thoughts?
the EFI turbo guys go nuts with the fuel system on a rotary, so i'd be cautious, but then again the EFI turbo guys go nuts with the gasoline fuel system too.
E85 needs something like 30% more fuel, so if you can do that, you'll be fine.
b) try it. you probably want to change fuel filters, and then let the gasoline get really low, and just put E85 in, and get tuning
Soaking the carb in pinesol undilluted really loostened most fasteners!
I did use a wire brush after the toothbrush wasnt cutting it. Chemdip might have cleaned it better.
Msd 2225 pump
Dissasembled. Still a little rusty.
My "work bench" coffee table.
Do you think the "JB weld steel stick" will work as well as the quick steel?
I was mistaken about the complete awesomeness of my wheel deal. And I had to buy these from ezaccessory.com @ 1$ per. and some lug nuts
Soiled pinesol.
/IMG]
I searched high and low for a washer the same diameter as the venturi and I couldn't find one, however I found one that was rounded and I thought that it might center the rounded surface of the venturi. so I placed the carb body on top of my toaster oven at 400 for a while I don't know exactly how long it was on and off all I was figuring it out, it was just warm to the touch maybe ~102°f and then I sprayed it with compressed air to cool the venturi and tapped the venturs out.
My diagram. Not a great refference for anyone but me, just showing my work.
here are a few more pictures for reference, some of them before it was cleaned. Also I used books for holding up my carburetor instead of wood. I thought that was clever me improvising but now as I'm typing this it sounds condescending. I don't mean for that
Also did the stock needles have rubber tips?
P.S.S. I've come to the conclusion that I cannot shorten my shocks because the adjusters are on the top of the Tokico illuminas. however I might still be able to thread them down further and get an inch and a half or so extra room of shock travel. bill just stick out of the top of the camber plates and look goofy I can go as low as I can clear the hood.
Edit: i only got one check ball out of my carb. I fear i lost one is there anything that would work in its place
And the machine shop has my turbo manifold to make me a flange, they're also making mounts for my coil overs.
Last edited by perfect_circle; 06-08-15 at 11:22 PM.
05-28-15, 12:24 AM
Beating a Dead Zebra? (12aturbo questions again.)
I'll cover the specifics later.
is there anything that would work in its place
