Jeff20B

iTrader: (13)

At last count that is two carbs out of three that have been tuned but will need further work when some parts arrive. As for the third carb, I wonder if I can tune it all the way without having to buy anything.

25.15mm carb:
pri air: 60
pri fuel: factory 120
sec air: 105 (need to be smaller as there is a 1/8 second delay)
sec fuel: factory 155 (need to be smaller as it runs really rich)

Result: The primaries are pretty good. Lots of grunt and starts easily. Around 13 at part throttle cruise. Primaries had some drilled 118s that were a tad richer than the factory 120s in there now. The secondaries had 118 air bleeds at first and would spike to 12 during a delay/bog, then would go to 10.0 on the wideband. Then swapped to 105 and the delay was reduced a little and spiked not as lean. Still more tuning is required but over all a pretty good carb. Could be used as a daily right now except for one thing...

This carb wants to flood easily due to needles and seats that aren't "burnished in" yet. So will probably retune for NA use and put a few miles on it before returning to boost. Also don't have enough tuning parts for a proper boost tune on the secondaries right now anyway. Oh well.

wankel=awesome

Your carb that has the lean spot, we could hit this from both sides.

If fattening up that idle circuit made it go away, were on the right track. But theres such a thing as too much of a good thing, which you saw with the super rich idle circuit (ala RB 465).

SO, now that we know it certainly needs a fuel cover, dial that pri slow air bleed to the smallest you can that the car will nicely idle and cruise with.

After this, reduce the size of your primary longs and main air bleeds to make the circuit come online sooner.

If theres still flat spot up there AFTER a deep tip in (not slowly accelerating) you may need even more accel pump work. (slightly larger nozzle, although this may hurt your secondaries response time!)

Fattening up all of these circuits a little bit should give you coverage from multiple places without sacrificing too much drivability.


I know it CAN be done now that you eliminated it with a fat tune. It'll just take some time and testing to figure out where we can get the fuel it needs.

I base the low speeds and mains as the culprit, because as the nikki primaries get bigger, it has seemed to be linear in needs to richen certain circuits. What youre seeing is what you SHOULD be seeing when a small carb gets big, so youre on the right track in my opinion.

Jeff20B

iTrader: (13)

Yes, let's hit this from boith sides. Glad to know this carb is in familiar territory.

90 is too small for it to idle well, so we know 90 is too small and we know 118 is too big. Didn't test cruise but I did slowly rev to keep the accel pump from coloring the results. No lean spots. Around 5 or 6 grand is where it wants to boost on primaries only so it started coloring the results. No lean spots with 90s but it has a couple misses here and there. By a couple I mean few and far between randomly at any RPM so not a big deal to me at all. I think most carbed rotaries do this as the Hitachis did it too.

I wish I could reduce the size of the primary longs. 42 is the smallest I have. I might look into smashing a lead pellet from an airgun into the top to block off the .42mm orifice and just let the slow bleed flow perpendicularly into the opening in the side of the long, then down in the transition circuit. Would this make it come online sooner?

Curious how a bigger nozzle would hurt secondary response time. I think I've got plenty of pump shot already when they open, but of course I could be wrong. Gonna get a pack of tiny metric drill bits and try different sizes bigger than 118. See if the secondary bog can be gotten rid of with a bigger nozzle.

I like the idea of fattening up everything. Sounds like they all need some small tweaking, and that it's doable. The drivability of this carb is already not as nice as some others, probably due to the lean areas, so I've got little to lose. Might as well go for it. Anything it takes.

Hmm, I might get some 80 and 85 weber jets to fit in my modded secondary air bleeds. Or maybe I'll drill and tap for the nickel plated 60 thread pitch & diameter so I can start as small as 60 and work my way up in .05mm increments. That would save some cash but would take more time to set up the machine etc. Sounds like it's worth it though.

Yeah, the main bleed sizes I tested were 60 and 70. The 60s ran worse and still had the 1500 to 2000 lean spot. The 70s ran a lot better. Lean spot still there but you can drive it ok. Seems like the lean spot is mostly in the slow bleeds.

Jeff20B

iTrader: (13)

piercemanifolds has a wider selection of weber jets than I thought. From 40 to 250. Every size we need!

Product Index

The jets we can use start at 73801.040 (scroll down a bit). 73801 is the jet type and .040 is the orifice size.

wankel=awesome

My theory is that when you mat it for the secondaries, some fuel from the pump shot is still flying out and helping to cover that transition. Making the pump nozzle bigger makes it go through its supply of accel pump diaphragm faster, meaning if it were too large it would dump it all before they opened...

Jeff20B

iTrader: (13)

Good thing I have a few spare stock nozzles to try.

Update: The tiny drill bits have been ordered. I got them from here:
Drill Bits and Pin Vises

Scroll down to "Metric 15 Piece Drill Bit Set 0.30 to 1.0mm" and the one below it "Metric 15 Piece Drill Bit Set 1.05 to 2.00mm" and then look for the pin vice(s) they recommend.

Qingdao

iTrader: (3)

Haha, I have "Pin vise and drill bit set". That's how I made my 118 holes. I got mine through ebay though.

I wish it came with a pouch with individual numbers written on it. Because I have a dickens of a time figuring out which bit is what size.

Jeff20B

iTrader: (13)

I'm sure I'll have a dickens of a time remembering which drill bit I used on which jet. But it does seem like the most economical way to tune when jets cost around $4.30 each. You can only get eleven pairs for a hundred bucks.

I was thinking about getting some blanks and drilling my own but was like hold on, why get blanks if they costs the same? Why not get some weber 40s instead? The existing hole will help center the bit making hand drilling that much easier. Then if I need an 85 as an air bleed, it's easy to do. Or a 125 fuel jet. Or like wankel=awesome was saying, a short slow bleed smaller than 118 to get rid of the Nikki off idle flat spot.

Jeff20B

iTrader: (13)

The 40 air bleed under the air horn over by the altitude compensator has direct communication with the primary air bleed circuit. This should be blocked off when you boost prep because it lets in too much unwanted air. Study how and where it flows to see what I'm talking about.

I blocked mine off today with a spare brass bolt from the power valve area of a spare carb (it covers a long brass weight). The results were predictable. I knew I would need to turn the mixture screw and throttle stop screw a little to account for 40 less air coming through the idle circuit (20 per side), and I was right.

The carb I tested this on is the 25.4mm. It has a less pronounced 1500 to 2000 rpm lean spot than the others. What you see is 12.something as you start reving it, then it goes to 13.something through the lean spot, then back to 12 briefly around 2000 which then hovers in 13 territory as you continue to rev it all the way up. It will go to 6 grand on primaries cleanly, then when you floor it there is a tenth of a second hiccup as the secondaries open and it goes to 8k fine. Also saw a fuel pressure spike to 14psi on the gauge installed on the mallory.

Then the engine returns to idle like nothing happened. Fuel pressure back to 2psi (was starting to get lowish on gas so didn't drive it, but usually runs at 2.5psi with more than 2 gallons). Didn't flood, which is nice.

I'm going to up the primary fuel jets just a little. Also need to test drive on the new secondary tune. Check it out and let me know what you think.

25.4mm carb:
pri air: 70
pri fuel: drilled 118 (will swap to 122 or 125 next)
sec air: 94
sec fuel: 140

Does it look like the secondary air bleeds and fuel jets are too small?

Qingdao

iTrader: (3)

Looks like you got a numbered pouch to keep your bits in. Mine all go back into the vise itself and jumble together in one place, its a nightmare of anti-organization. When I did motorcycle carb tuning with that blue drill bit kit I showed you; the plastic kit kept the bits organized. Organizing the jets was a simple as scores along the side of the jets. I only messed with four or five different sizes so it was easy to keep track of with tick marks. If a jet missed the ticking process I could see the difference in jet size. You'll be VERY impressed with how accurate your eyes are at determining small changes in orifice size. I could tell the difference between a 115 and a 112 mickuni jet when I was doing the bikes.



Alright, I'm starting to understand the Nikki (in my defense I haven't given it too much thought until lately). But now I'm getting it so I can chime in.


As I understand it the Main Air Bleeds work across the board. The Slow Air Bleeds affect partial throttle. But my confusion is why are there 2 sets of Slow Air Bleeds? Does one start sooner than the other?



Jeff, if I may suggest blocking off the Accelerator pump until you have a tune for the rest of the carb. The accelerator pump should be used for transition to a different throttle position, and it just seems to be confusing things at this point.

Jeff20B

iTrader: (13)

It's my understanding the short slow bleeds affect idle and partially affect transition. The long slow bleeds affect transition. The main air bleeds partially affect transition and anything above.

There is one more air bleed circuit that affects idle and to a lesser extent transition. I mentioned it yesterday. The tall 40 air bleed up under the air horn over by the altitude compensator communicates through the holes that lead down into the lower area of the main body. It splits apart in the air horn so it feeds an additional "20" of air to each idle circuit. Not much, but it didn require me to reset the idle mixture screw and throttle stop screw.

I skipped over it during my initial hogging out process because I didn't understand it, and it didn't seem to do anything. I guess I figured it was blocked off by the aluminum plate when you delete the altitude compensator. For NA it doesn't seem that important but for turbo and fine tuning, it's best to block it off.

Same thread pitch as a short slow air bleed. I'm sure you can find something in your collection. I found a brass screw cap as mentioned above but a solder filled brass slow bleed could work.

I guess I'd be worried about it coming loose; either the solder glob or the bleed itself. Probably why it is so tall, so if it does loosen up, it can't fall in the carb. Hmm, maybe some red loctite or tap a couple of spare accel pump steel ***** in the holes in the main body. That's what Yaw did.

Now you have me worried about it. I'll probably use some red loctite because I don't have enough steel ***** and don't know how well solder would work with such a tiny amount up on the threaded end of the tall 40. I suppose if I filled the whole thing and it came loose, it couldn't fall out.

Maybe I'm overthinking things. I'm sure some red loctite on the short cap screws will keep them in place.

Jeff20B

iTrader: (13)

So I used some red loctite on the short brass cap screw. When I removed it to apply the loctite, I got to see the friction pattern created by the cap screw against the air horn metal. It looks pretty good with nearly full coverage. I'd think this metal on metal contact and the threads together create a good air tight seal. Also with a head this large it should have enough friction to keep it on without ever coming loose by itself. Think about it - they don't come loose when installed in the main body. But I applied loctite anyway as there is no need for these to ever come back out of the air horn. Even a simple degreasing/washing shouldn't require this screw to ever come back out as long as you have compressed air handy.

A good reason to block this air bleed off is in how it affects the primary air circuits. It affects whicever circuit is active at that time the most. So at low RPM all of its air is going through the idle circuit. Then at transition it is affecting the transition circuit and the idle circuit somewhat. Then it affects the main primary circuit when that circuit is active. But at higher RPM like that, its influence is less noticed. It really only makes a noticeable difference on the idle circuit because a small change down there makes a big noticeable difference.

If you look here at the two green circles:


These are the holes leading from the tall brass 40 air bleed in the air horn down into the primary air bleed circuit in the bowels of the carb (I said bowels, not bowls). Allowing the 40 bleed to remain open lets in 20 worth of unwanted air per side.

I hope all this makes sense to you guys. Even if you don't understand any of it, go ahead and block off the tall 40 because leaving it open affects your primary air bleed circuit in ways that make air bleed tuning more difficult as the results often don't match the theory and you'll be chasing your tail like I was for a long time.

If you don't have a spare cap screw like this one (circled in green) to install in your air horn:


You can still fill your stock tall 40 with solder. You're going to have to fill your primary short brass bleeds and secondary long bleeds with solder anyway, so have them all out and ready when solder filling time arrives. I'd recommend filling the tall 40 to the top and recut the screw slot with a hack saw blade or whatever. This makes it less likely for the solder slug to fall out or come loose in service or when you're tightening it back into the air horn. You must use lots of torque as you'll discover upon initial removal. No other air bleeds in the carb are this tight. As this is the original part for this hole, I'd say loctite is optional but only if you reuse the orignal bleed. The factory didn't use a thread locker here.

Again this thread isn't about holding anyone's hand through the boost prepping process, but because this is a new mod, I felt it deserved adequate attention due to how potentially important it is.

Jeff20B

iTrader: (13)

Adding more info to this thread.

I just looked through this https://www.rx7club.com/1st-gen-arch.../#post11407754 and feel it is a great place to start for anyone who is kind of a noob at carb work. You gotta start somewhere, right? This tutorial is pretty good. He gets most things right on. Other areas can use some work such as filling the ACV port with quicksteel and how he got the choke shaft out, but it's definitely good enough to reference.

I think the tutorial, together with this thread and some forum searches, covers everything pretty well. Now you guys need to pick up the ball and run with it! I'm getting bored over here!

Jeff20B

iTrader: (13)

The micro drill bits arrived so I got to measure them and tried a few already. Turns out the 1.25mm bit was actually 1.22mm which is what I needed for one of the carbs. Perfect!

Some bits are pretty accurate while others are off by just a little. I was able to check the ID of some old Hitachi 140s and turns out they were drilled a bit bigger than 1.40mm. One set was about 1.41mm and another set was about 1.42mm. Just guessing as the drill bit came in at 1.39mm and was quite sloppy.

A set of factory 150s were tested with a drill bit that turned out to be 1.46mm and not 1.50mm as advertised. The factory 150s are probably around 1.47mm.

Just a note on tuning: I went from the undersized 150s to the over sized 140s but only reduced the actual orifice size by 5 numbers (147 - 142 = 5) which is exactly what I was looking for.

I think the carb is 100% tuned now with 122 primaries and 142 secondaries. How's that?

Most of the air bleeds were a bit more accurately drilled from the factory and some of the drill bits in these sizes were also pretty accurate. Rather amazing day getting to see what the actual orifice sizes are.

This is for wankel=awesome. The carb that had the lean spike at 1500 to 2000 got a set of short slow air bleeds drilled to 105. Think this will fix the lean transition? Think the mixture screw will still do something? Still within its range?

It also has the rare 42 long slows and the altitude compensator 40 air bleed has been blocked off. I've maxed out or rather minimized all air bleeds on the primary side as small as I dare go. Think this will reduce the secondary delay as well?

Speaking of secondary delay, this carb has the smallest jets being used as air bleeds I have, a set of factory 91s which I tested with a .90mm drill bit that turned out to be .89mm. This bit will not fit making me think the jets are actually more like .88mm or .87mm. That is pretty small for secondary air bleeds, is it not? Or do I need to go smaller if I still have a delay? Am I on the right track? Thanks.

wankel=awesome

I think the long air bleeds are the primary air source for the transition circuit after studying mine. I think those getting smaller are the key to the covering the gap until the mains come online.

Seems simple enough, just go down sizes on your long air bleeds and log the changes. Its an extra point of tune we havent really played with much yet.

Jeff20B

iTrader: (13)

wankel=awesome, as usual something you said clicks and now I know what to do next.

See this tool I posted earlier?


The end has a nice inverted cone shape. I think if I set the little pointy end of a long slow bleed in there and tapped on it, it would drift the drilled orifice smaller.

Now that I have a set of micro drill bits all the way down to .30mm, I can check the orifice and keep drifting it smaller until I get it to the desired inside diameter.

It might not be the best tool for this, but I don't know of anything else right off hand. I think if I lube it with WD40 it just might work. Your thoughts?

wankel=awesome

Go to a sporting goods store, and buy some 1mm lead shot. one bag should last you a lifetime. Tap the 1mm sphere into the orifice until it smashes flat, (I use the backside of a dull drill bit, they come in many sizes so its a nice tool for this) Then drill the smallest one you can, and try it. I'm pretty certain this is the missing link.

Its an area that at the very least works towards transition, that is left stock most times.

If the Slow air bleed and the High speeds needed to be smaller, it stands to reason this component should be too.

Jeff20B

iTrader: (13)

The hole at the top of your typical 46 long slows are around 65 (tested yesterday with the .65mm drill bit) so I can see how adding something like lead shot and drilling it smaller could help. However it will still get air from just under the threads from the short slows. Take a look at yours to see what I'm talking about.

The calibrated 46 hole is at the bottom. This is what I was talking about "drifting" smaller with the nail punch tool. But I understand how making the hole at the top would be a good thing too.

Speaking of which, I have a set of old school 50 long slows. The hole at the top appears to be 50 and the hole at the bottom is kinda big looking. I think Nikki updated these to move the calibrated hole from the top to the bottom for some reason. I might try "drifting" the bottom holes of these down too. They're 50s. Way too big. What have I got to loose?

wankel=awesome

Nothing, try it. Thats how this stuff gets figured out haha

Jeff20B

iTrader: (13)

Disappointing news about the long slows. I spent several hours on them and tried everything just short of hammering them down, and nothing worked. Then decided to go for broke and began hammering at about a 45 degree angle which was the only thing that made the hole any smaller than .50mm, but now it looks terrible and I don't want to try it in the carb anymore.

I'm open to suggestions.

After today's failure I tested the 42 long slows in the carb instead. Here is the full list of mods followed by the results.

25.6mm carb
Primary list:
105 drill short slow bleeds
42 long slow bleeds
70 main air bleeds
blocked 40 tall slow bleed under air horn
factory 130 fuel jet (about 1.27mm)

Secondary list:
91 main air bleeds
factory 140 fuel jets (About 1.41mm)
solder filled long and short slow bleeds

Result:
The 105 short bleeds required the mixture screw to be cranked in a bit, as predicted.

The 1500 to 2000 glitch IS STILL THERE and is more noticeable when the mixture screw is adjusted around 12.2 on the wideband. The glitch is less noticeable when the mixture screw is at 11.something. Seems like it wants to be richer. The drilled 105 short slows didn't really do much as the mixture screw sort of negates their effect. I'll probably keep them though.

The only conclusion is I need smaller long slow bleeds. Any ideas to neck down the tiny hole at the bottom?

Then I tested the carb in NA mode with the carb hat removed. What is happening in the carb when it's having its lean glitch? Strangeness. First fuel starts emitting from the front booster, then stops and switches over to the rear booster, then both emit fuel and the engine runs smooth as you slowly idle it up. WEIRD! Why would it flow from one, then stop and jump over to the other? Seems like it's sharing a vacuum signal somewhere, to just jump around like that.

I think it is the altitude compensator holes in the main body because they're Teed together up in the air horn. Things follow the path of least resistance so I think once they're blocked off in the main body, then the carb has no more excuses. It will either even out the transition or it won't, but it eliminates that as a possibility. Thoughts?

Oh but the good news is it revs quite well and the mallory responds like it should (saw a pressure spike past 14psi ). The carb returned to a nice idle too. Compared to a year ago, this is a major improvement. The primaries used to hate reving past 5k and the secondaries would have a really long delay. Now when you free rev it, it just revs.

Jeff20B

iTrader: (13)

Here's a crazy thought. Do we really even need the long slows? Can't the short slows and the idle circuit cover the transition? Will the transition circuit go super rich if the long slow's tip is pinched off? Do we want that?

I only ask because blocking off both slows on the secondary side did lead to a dramatic improvement in the delay time from 1.5~2 seconds on average down to 1/4 to 1/2 second average. That's a big deal! The forced air coming in was killing off whatever vacuum the secondaries were trying to make under boost so it took a while to get going. And of course there usually will be boost present whenever the secondaries open, so you see my point.

So what about on the primary side? Some major idle problems we reduced dramatically by going from the original 170 short slows to the drilled 118s, but didn't improve much with the drilled 105s. It seems only going way beyond the usual idle tune of 12.2 into pig-rich territory of 11 and even 10 gets rid of the 1500 lean spot. The only problem then is the idle is so rich it doesn't run right at the lowest RPMs anymore. But that 1500 glitch is gone!

So there's gotta be a way to keep the happy idle but get rid of the glitch and the only thing coming to mind is to reduce or block the long slow bleeds.

wankel=awesome, you've said when making a small carb big, it wants you to reduce the air bleed circuits. In my case I had to totally block the secondary slows and reduce all the rest. It makes sense that the last hold out to a happy carb is the one area which we haven't addressed yet; the primary long slow bleeds.

Idea time!

Since one of the 50s is kinda ruined, I won't be using them for this next idea. I do have one spare set of 46s, so I think I'll try smashing their tips and testing in the carb tomorrow.

Do you think this will make the mains come online sooner? Will it be soon enough?

Jeff20B

iTrader: (13)

Turns out we do need the long slows. With them crushed, the carb complains. A lot. Sure it starts and you can keep it running with your foot, but it runs really rough and the wideband is all over the place. It's also hard to keep running. The behavior is a lot like when I recently tested the carb without main primary air bleeds. Practically identical behavior.

Next test was to just try the 50 long slows. Because one had a necked down tip, I was expecting the booster on that side to emit fuel earlier in the RPM range than the other with the stock 50 sized hole. Also I was expecting the idle to get really rich because the holes in the tops of these old school 50s are actually .50mm unlike the modern 46s that are closer to .65mm. Expecting this richer idle, I swapped the 118 drilled nickel plated 60s back in.

The result was as expected! Gee maybe I am beginning to understand this carb tuning business after all. The idle was way rich at 11.6 and the engine brapped most of the time. Lol fake bridgeport for the win? Also as expected the side with the necked down air bleed did emit fuel earlier in the rev range. Infact the other one took a really long time to start emiting fuel due to being .50mm at the bottom, not the more common .46mm which emits fuel earlier. So if this doesn't tell you anything, go back and rear this entire thread.

Just to make doubly sure, I swapped positions of the long slows and sure enough now the other booster was emiting fuel early and the first one was now absent until a higher RPM. Looks like I'm on the right track.

So I figured I could neck down the tip of the remaining 50 and also drill out the top to .65mm. I got familiar with the pin vice and tiny drill bits. I drilled in steps from .50mm (just to make sure), then .55mm, .60mm and finally .65mm. Then as I was hammering the tip, it cracked and split apart slightly. Great. Why didn't it work this time? It worked well enough yesterday.

So then I grabbed a 46 long bleed and started hammering it. All was going well until it cracked as well. Ok, I guess these things don't like hammers today.

At this point I have no more spare long bleeds to practice on. All the rest belong to a carb. Whatever I do next I have to be very serious. No more possibility of screw ups.

I came up with an idea yesterday to use an old chuck from an electric drill. I hoped the three fingers would come together and squeeze the tip down. I got a little experience with this yesterday when I crushed the tips of two expendable water damaged ones in a small drill press vice. I recall it didn't take all that much effort to get a good airtight crush.

So I grabbed the chuck today and got started. The three fingers would come together equally most of the time and did an ok job. Then I'd round the hole back out with a micro drill bit and crush some more. The end result is smaller than the smallest drill bit I have. So I had to grab a bit of electrical wire with thin copper strands. Tried .31, .25 and then finally found a .27 which had trouble entering one but went into the other well enough. So I took a single strand of coarse stainless steel wool and used it as a file until the .27 wire could go in this one as easily as the other.

After refining my crushing technique I now have two sets of long slow bleeds in .34mm. The drill bit is .34 and I cleaned up the triangular shaped holes with it. One set is still more triangular than the other, so there will be some swapping back and forth if necessary until the 1500 lean spot is gone! Either way they're only expected to pass air, so perfectly round holes would be nice but they're smaller than stock and that is what matters. I also look forward to trying the .27mm bleeds if the .34mm just don't quite do it for me.

By the way the necked down 50 from earlier is probably around .28mm or .29mm as the .27 wire had no problem fitting but the .31 wouldn't go in at all. It flowed like it had a healthy prostate so I know I'm in the ballpark. Just needed a bigger upper hole, is all. Don't we all?

Man it's nice to finally unshroud the mystery surrounding the long slow bleeds! Gaining a working understanding of what they actually do... I wonder if this is one of the secrets Robert or the "carb brothers" Carl and Sterling didn't want to talk about? Out of fear of losing sales? Nah, something tells me they never dug quite this deep into any of their carbs because the biggest venturis they ever did was only 22mm. And in Robert's case, his stock 20mm venturi carbs that were boost prepped wouldn't have needed smaller long slows either.

Heck I got this far having never modified any of mine, literally until yesterday and today. Took me about 24 hours, give or take, to figure out how to neck them down in a repeatable scientific (lol) way. Can't wait to test run them!

Jeff20B

iTrader: (13)

Turns out they don't work very well. Oh well.

Tried three different drilled sizes (including .42mm).

.27 result: did't want to idle, didn't really want to run at all as mains would come online basically at idle

.34 result: kinda could idle but mixture screw needed way backed out, ran poorly, mains wanted to come online too early just above 1000rpm and continued to 2000rpm.

.42 result: could idle almost normal, classic 1500 to 2000 lean spot was so bad I'd see 17 on the wideband and the engine would stall

Went back to factory 42 long slows and swapped 105 drilled short slows back in.

Result: So much better! The 1500 to 2000 lean spot is not very bad and the engine starts up easily and doesn't vibrate as much. Also drives really nice now. The best it ever has. You honestly don't encounter the lean spot very often and when you do, it's so minor it feels like an accel pump issue (which at this point I suppose is a possibility). Either way, I'm happy with the way it turned out. Just needs some minor fine tuning on the jets and main air bleeds and that's it!

There is still a secondary delay but it's only in 1st and 2nd gear now. For some reason 3rd doesn't delay anymore. Must be all the primary air bleed work I've done recently. So I think a slight reduction in secondary air bleeds. Maybe try 85 next from the current 92. Also the current sec fuel jets are 141 so I might try 135 next as the wideband still shows 10.0 in boost. The primary jets are factory 130 or around 1.27mm and seem slightly rich. I'm thinking 1.25mm would be perfect.

wankel=awesome, my part throttle cruise is around 12.something. Is that too rich? Do I want leaner? I'm thinking as the weather warms up I might want to jet it down (1.25 or 1.22). Correct me if I'm wrong. Thanks.

wankel=awesome

Shame on the long slows. Did you try just modifying the tops of the bleeds? Its its air supply after all...

I think 12 is way to rich for cruising. You should be cruising at around 13-ish for a performance carb. The OEM would be around 13.4-14 flat for gas mileage and all that.

So, youre very close. What is your WOT afr with turbo?

Jeff20B

iTrader: (13)

I tried the long slows with the .50mm holes in the tops and it made the idle too rich. So going smaller up there didn't work for me. They do get air from the short slows too. Take a look into both holes in the carb's main body to see the channel connecting them.

WOT is 10.0 as soon as the secondary delay is over.*

It kinda gets to around 10.0 even on primaries if I'm really getting on it causing the turbo to spool. Otherwise it's in the 12 or 11 territory. Sometimes I see 13 but it fluctuates a bit as you free rev it. But actual driving is usually 11 to 12.

*I didn't mention how short the delay is in 1st and 2nd now. It is really short, like 1/8 second or so.

Do you think a set of smaller secondary air bleeds would get rid of the delay once and for all? Current bleeds are 92. I'm about ready to fill a set of old 160 jets with solder and drill for 80 or 85.

As for primaries yeah they're so close! I think the only way I'll get to the magical 1.25 is to order a set of weber jets because the micro drill bits skip from 1.22 to 1.30.