Opinions/Knowledge on Triple SU's

[e_racer1999]

1-5-3-6-2-4

Therefore, if the carbs were labeled A-B-C from the front of the car you'd have ACBCAB instead of the normal ABABAB. Each carb would be used once, have a one cylinder gap, be used again, and then have to wait for 3 cylinders.

the article was from zhome.com:

http://zhome.com/ZCMnL/tech/TripleSUs.htm

what the article states is that it causes "flow reversal" because of dead usage spots...... it's in the article...

[beandip]

1999 , good call , this is what I was going to say. Its all about the sequence and the interupted flow of the air mixture that deminishes the charging of the cylinders. Insted of the mixture continuing to move in a direction of the cylinders and there fore , to a degree , packs or compresses before the intake valve closes . It is interupted and stops ,then has to start again , thus loosing the ram effect. Tripple Mikunis or Webbers on the other hand amount to having one carb per cylinder , and with the correct stack can maintain the volicity of the mixture to the cylinder. They would look cool though.

[kyteler]

I find it odd how people constantly regurgitate the info. shown on that website and yet, as people have mentioned, there ARE other Inline 6's that run triple SU's and some people even know other's personally that run them, it's a completely viable option. The GTR-XU1 Holden Torana's that ran them were not slow by any means.

I have a manifold that I would be willing to sell but it needs to be tidied up, as it's put together pretty shabbily and both int. and exh. manifolds don't fit on together due to the int. manifold needing a little bit shaved off it in places.

[Alan Pugh]

Michael,

I suppose the same old info is brought up all the time because it is accurate.

I owned an LJ GTR XU1 and contrary to popular opinion they did not come out with triple SU's they were infact triple Stromberg 175 CD carbs.

Yes the car was very fast new, and then I fitted a set of twin 2" SU's and got the full performance out of it. There was also some head, cam and exhaust work done but the twins do flow better.

If you want to fit a set of triples, fit a set of triples, but if you ask advice be prepared to read the responses you get.

Alan.

[kyteler]

Alan,

I have read the information before and I actually have a feeling either some of his thread is missing or perhaps it was also split into a series of threads. .. not sure.

This thread was actually created last year and today when the man from Sweden posted it spawned the replies yet again.

I understand that it may very well be accurate but by the sounds of most the responses in regards to this issue that I've read in several other places, they seem to essentially say "no, you cant do it because it doesn't flow right" and also certainly don't sound as though they're speaking from experience but more because they've read that website.

I'm not interested in running triples myself any longer, I got that manifold that's mentioned above for bugger all but it requires work taht I can't be arsed completing in order to be fitted and then tuned ontop of that, so I just held my breath and waited for a twin setup to come about, and about 2 months ago I picked one up complete with an N42 L28 for $300NZD .. not too shabby

Also, thanks for the clarification on the GTR-XU1, i guess that also goes to show you can't trust everything you've read or heard before, even if it isn't on the internet

[Alan Pugh]

Michael,

I should have looked at the dates.

I agree that saying it can't be done is wrong, it's more a why would you bother.

I suppose the triple issue is never going to go away, next time maybe everyone should answer yeah there great do it. Then you'll get a new thread something like, I've fitted triple SU's and can't tell the differece, WHAT"S WRONG.

Alan.

[beandip]

It is not the inline 6 it's the FIREING ORDER !!!!!! what works on another inline engine is of no reguard here . The tripples will work but the gain in minimal . I say go for it . Do it . but take the car to the dyno first then after the install and report back . They look good . run with out air cleaners and they sound good. Some people like the stainless buckets on the hondas too.

[kyteler]

:stupid:

The firing order has been discussed before also.

There's a thread here;

http://www.classiczcars.com/forums/showthread.php?t=13908&highlight=triple+SU

and another one or two floating around.

I fail to understand how another inline six that runs the same firing order (the 153624 that MOST inline sixes run) would be of no regard.

Nevermind, this is a waste of time. :ogre:

[Z Kid]

Just while you are on the topic of firing order, I would love for you to suggest a firing order that provides the required balance that doesnt end up with the same pattern as the L series/XKE engines in terms of carbs used/timing of firing. I have been thinking and thinking, and no matter what combination you use to get it to fire, in order for it to be balanced it has to have the same sort of ratio or carbs to cylinders and firing times. Incidentally triple SU's have an advantage over the webbers on other cars in terms of drivability because due to the venture style and lack of a pump type setup within the carb, when you put your foot down you cant really flood the engine unlike the webbers which can create a lot of popping and farting. I think well done with equal length manifold runners it could be a great conversion, and they really are a very simple carb to tune.

[e_racer1999]

why don't we just do 6 SUs and call it a day!

[240znz]

Not such a silly question considering that individual flat slide mukuni's are used on motorcycle engines with great results. I wonder if it has been done on a L series engine? But what a massive PITA to set up, just imagine the linkages....OMG :stupid:

But as Michael says, he has twin SU's now, so he'll just use them and to hell with the exercise and self emptying of wallet.

[e_racer1999]

i've heard (from here or hybridz maybe?) of somebody doing that but with bad results...... from what i've heard they wont idle under 3000 w/o popping and stuff......... anyway, i've been considering doing some research on that and thinking it would be cool as heck!

anyway, i'm sure someone will let us know....