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SU needles https://www.ausmini.com/forums/viewtopic.php?f=2&t=13313	Page 1 of 1

Author:	J_A_M [ Sun Nov 20, 2005 7:31 pm ]
Post subject:	SU needles
Not a questkion, but rather a comment.... Last week I changed my SU needles (Twin HS2's) to M's. Today was the first BIG drive with these needles, and I used half a freakin tank of juice to drive about 20km! (on the motorway too - non stop driving!) I played with the mixture, making it leaner....but I can tell when it's at the point of being too lean.....so the mixture felt OK while it was chewing up my juice. Needless to say as soon as I got home I put my AN's straight back in. That's what I have been running since JAM was registered. Here's a question about SU neeldes though......2 AN needles, but different lengths. From the base of the needle taper there was about .100" difference in length. What the?!?!?

Author:	drmini in aust [ Sun Nov 20, 2005 7:36 pm ]
Post subject:
I'd say one has been chopped... is it really marked AN? Slow down, it'll use less fuel....

Author:	J_A_M [ Sun Nov 20, 2005 7:41 pm ]
Post subject:
nah...not chopped....both have the same point at the end....and yes, both marked AN......i can read

Author:	TheMiniMan [ Sun Nov 20, 2005 8:32 pm ]
Post subject:
It`s really not a matter of how "long" they are as the carb doesn`t ever see the very bottom of the needles anyway,,,so any extra length basically has absolutely no bearing on the quallity of the mixture the M`s are just obviously too rich for your engines state of tune with a slight lean-ness , the engine "WILL" feel it & so will you, (cought splutter, blow back) BUT!!!!!!!,,,a slight (or even more than slight) richness & the engine won`t be bothered too much at all,,,, it`s when it`s WAY rich that it`s noticable & also the plugs begin to foul with soot so,,,if you can understand what i`m saying here,,,a little lean & it`s not real nice,,,but a little rich & it`s ok-ish,,,just chews more fuel than it needs to & can "Dry" out the bore a bit & also can shred/wear the valve guides prematurely too i`ll shut up now cause i`ll type about this sh!t all night otherwise

Author:	Mike_Byron [ Sun Nov 20, 2005 8:39 pm ]
Post subject:
Anton I would be looking at other things as well - such as the bell springs, damper oil etc. BUT, the needles haver to be identical. well maybe not but it helps for your type of setting up. I have a good little program that gives a good idea on what needles could be used for various engine specs. I can't openly offer you a pirated copy of the program so PM me with your address and I will see what I can do. The program is called WinSU. I also have a colourtune kit but its here and staying here.

Author:	drmini in aust [ Sun Nov 20, 2005 8:45 pm ]
Post subject:
Mike, Anton's already downloaded WinSU... Anton- you really need to put an A/F meter on to get it accurate. I'd either go see GR, or put it on the dyno at MRC Castle Hill.

Author:	aaron [ Sun Nov 20, 2005 9:24 pm ]
Post subject:
Do MRC have the needles to rejet the SU's with? Cheers Aaron

Author:	h0nk [ Mon Nov 21, 2005 4:48 am ]
Post subject:
Anton I'm running the same size engine to you (except I've got a crappy stock 998cc head, and no RE13 cam) and I'm using M needles in my HS2's.. They don't seem to use a great deal of fuel to the previous needles I had in them. That seems strange to me that yours uses a lot more.

Author:	drmini in aust [ Mon Nov 21, 2005 6:09 am ]
Post subject:
In the past, I've found twin HS2s go very well on modified 1098s using either M, or AH2 needles. No MRC don't.... but they are close to you- if you run it up there you can at least see if it is rich or lean. Or take it down to Mini Classic's dyno, I'm sure Greig has heaps of SU needles.

Author:	J_A_M [ Mon Nov 21, 2005 7:53 am ]
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What I might do is change my exhaust this week to a twin box RC40 and see if that does anything. The current 2 inch exhaust is too big, and the straight through muffler has shot baffles. This 'might' have an impact on economy. I am going to get my brother to send me the HIF38 I bought a while back. It's sitting in his flat in London. I will rebuild it and run that to see what it is like. Then I will make a decision about keeping that, OR putting the twins back on and getting Greig to tune them properly. I hear he is VERY good with twin SU's.

Author:	Mike_Byron [ Mon Nov 21, 2005 8:03 am ]
Post subject:
I dont think you will be sorry with the HIF series. It will run a 44 just as well as a 38. What manifold do you intend to run. ? Make sure you get your brother to send over a HIF throttle cable as well as it has a little plastic pre-tensioner do-dad on it - makes mounting so much easier and its dirt cheap.

Author:	J_A_M [ Mon Nov 21, 2005 8:24 am ]
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i have a cast iron manifold....didn't buy it....it came in a job lot that the inlaws bought. it will do for now....

Author:	poeee [ Mon Nov 21, 2005 8:39 am ]
Post subject:
Talking needles... i've got a pair of AH2's coming (they should arive at BMC today) to go in my beastie, to see if it gets better ecconomy off them. It has 4's in it at the moment, which aren't overly much richer than AH2's, but we'll see how they go!

Author:	J_A_M [ Mon Nov 21, 2005 10:54 am ]
Post subject:
what are they going in chief? the LS?

Author:	poeee [ Mon Nov 21, 2005 5:49 pm ]
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J_A_M wrote: what are they going in chief? the LS? Correct. I got them today, put them in to see how it went. It's running like a 1/2 dog, 1/2 Mini (not a complete dog, hehe), but that was only cause nothing else was done other than the change of needles. The rest will be done later this week, or next week. HOWEVER! I noticed a power increase! It wasn't much, but even a little is great! Hopefully it will improve more when it's done properly. I'll be putting the old needles back in untill the tune, can't be bothered playing around with the jets to only have them done again within a week!

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