Weber, Dellorto, Mikuni

[Fidelity101]

I have the mikuni 44PHH side draft carb on my S5 streetport and it is easy to change the jets out but the size is a little small but it still rips pretty good but with this cold winter air I am having a hard time adjusting the air because it leans out too much in the upper power band but it makes great mid range. Its hard because I hate dealing with wolf creek racing for jets, the guys is an ass hole. You would think you would be nicer to someone who is giving you money for relatively little work.

I cant afford a weber 50 DC SP unfortunately but thats what I need

I also run about 4.5psi of fuel pressure for the mikuni, it seems to like it.

they do make a mikuni 50PHH but you can only buy them in pairs

[TheBlack7]

Originally Posted by Fidelity101

I have the mikuni 44PHH side draft carb on my S5 streetport and it is easy to change the jets out but the size is a little small but it still rips pretty good but with this cold winter air I am having a hard time adjusting the air because it leans out too much in the upper power band but it makes great mid range. Its hard because I hate dealing with wolf creek racing for jets, the guys is an ass hole. You would think you would be nicer to someone who is giving you money for relatively little work.

I cant afford a weber 50 DC SP unfortunately but thats what I need

I also run about 4.5psi of fuel pressure for the mikuni, it seems to like it.

they do make a mikuni 50PHH but you can only buy them in pairs

what fpr are you running for 4.5 psi?

[Fidelity101]

Originally Posted by TheBlack7

what fpr are you running for 4.5 psi?

http://www.summitracing.com/parts/AEI-13301/

its the aeromotive 13301

I run a stock T2 fuel pump.

my FPR is about 10" away from the carb.

[rotaryracer]

This is a thread that I've been looking for. I bought a Mikuni (44) with 12a manifold. The folks that I spoke with said it was good to 200bhp. I plan on mating it to a 4pt Renisis. I'm getting good at building adapting manifolds and Carbs. I'll post picks in the 1st gen section. (it's going in a '79 SA)

[djmtsu]

Now I am looking for carb kits for an old school 13B 4 port.

I think jfaplanet has a Dellorto on his Repu, but not sure. It rips with that carb, so I was considering those.

However, a couple of locals have the RB kit and their cars run pretty damn good as well. Although, the Dell's look a shitload cooler

[730RWHP12A]

Originally Posted by Fidelity101

I have the mikuni 44PHH side draft carb on my S5 streetport and it is easy to change the jets out but the size is a little small but it still rips pretty good but with this cold winter air I am having a hard time adjusting the air because it leans out too much in the upper power band but it makes great mid range. Its hard because I hate dealing with wolf creek racing for jets, the guys is an ass hole. You would think you would be nicer to someone who is giving you money for relatively little work.

I cant afford a weber 50 DC SP unfortunately but thats what I need

I also run about 4.5psi of fuel pressure for the mikuni, it seems to like it.

they do make a mikuni 50PHH but you can only buy them in pairs

you should be able to get proper afr's with your existing carb. to richen up the top end try an emulsion tube designed to add more fuel at a higher rpm. or in the mean time try a smaller air corrector jet

[Fidelity101]

Originally Posted by 730RWHP12A

you should be able to get proper afr's with your existing carb. to richen up the top end try an emulsion tube designed to add more fuel at a higher rpm. or in the mean time try a smaller air corrector jet

I dont have the independent type jet block (e-tube) so I think I'm stuck with what I got but I did manage to get a smaller air jet. so whenever the roads are plowed I can take the rx7 out (with studded snow tires )

[TheBlack7]

finally got the new setup up and running. mikuni 44 w/ carter pump and holley 1-4 psi fpr and the car is unbelievable. shreds tires up through third gear! I love my mikuni! one question though, around 2k rpm it falls flat on its face HARD. above and below 2k it runs great though. u guys think its a fuel pressure thing?? or should i purchase some new jets?

[t_g_farrell]

Check to make sure your AP is making a good squirt. It should be part of what helps you get thru that progression from idl into WOT.

[dr.occa]

Originally Posted by t_g_farrell

Check to make sure your AP is making a good squirt. It should be part of what helps you get thru that progression from idl into WOT.

This is only my second post so apologies if it's a bit premature:

I've been running mikunis/solexes for years on my toyotas. I love 'em. What t_g_farrell pointed out is where I would check too: your accelerator pump sizes.

The size indicators can be a bit misleading. Just to give you an idea a 40 pump jet will squirt a larger amount at a shorter period of time over a 35. Make sense? So, it sounds like the progression from pilot to mains could be a lean bog due to either too short of a large squirt or to little of a long squirt.

I'd try going up a larger size though it'll be a shorter squeeze. It might be enough to straighten out that dip.

It could be balanced with a .5 step up on idles coupled with a step up on the pump jet.

[Fidelity101]

adjust your float level

[mattallac]

well i'v read all your posts and side draft carbs don't work well on N/A rotarys .44mm is to small for starters, 48mm and up .Down draft webers are some of the best carbs for drive ability and simplicity .Don't waste your time with side drafts the max performance will always fall short .I know you already own the side draft , they suck ......start with dyno runs ,holly will produce an average of 7 more hp over the down draft weber , but the weber is the better carb for corner carving (no starvation due to fuel slosh in the float bowl).Please sell your side drafts you will not get what you want in terms of performance.

[t_g_farrell]

Originally Posted by mattallac

well i'v read all your posts and side draft carbs don't work well on N/A rotarys .44mm is to small for starters, 48mm and up .Down draft webers are some of the best carbs for drive ability and simplicity .Don't waste your time with side drafts the max performance will always fall short .I know you already own the side draft , they suck ......start with dyno runs ,holly will produce an average of 7 more hp over the down draft weber , but the weber is the better carb for corner carving (no starvation due to fuel slosh in the float bowl).Please sell your side drafts you will not get what you want in terms of performance.

Your quite right on absolute performance but the side drafts with a wrap around
manifold gives you better torque down low for the street and makes it much more
drivable. Its all in what your looking for. You can't just say one is better than
the other, it depends on the uses and the drivers intentions.

I also agree that the 44 is a bit small for anything but a stock port 12A and even
then you will have some tuning to get it to a reasonable level. It will work but maybe
not as well as a 48.

[mattallac]

sure ,if you want torque a wrap around will sort of work , but in my experience tuning will never be right.I would rather use the stock carb and save my $.The wrap around is not that affective , if you want more torque just put spacer plates between your carb and intake ,the longer the runner the lower the torque curve.

[t_g_farrell]

Originally Posted by mattallac

sure ,if you want torque a wrap around will sort of work , but in my experience tuning will never be right.I would rather use the stock carb and save my $.The wrap around is not that affective , if you want more torque just put spacer plates between your carb and intake ,the longer the runner the lower the torque curve.

With a Nikki? I'd like to see that, post it up along with dyno sheets that show
how well it works that way.