A mate is interested in setting up a 1600 with EFI for khanas/rally. Of course it's a budget thingo. Lots more HP for no $$$ as per usual.

I'm currently looking into throttle bodies (TB) at the mo. The cheapest usable factory throttle body is a 40mm unit off a hyundai excel. They are around $50 each, so looking into the different in performance between singles and quads makes a lot of sense to see if we can get similar results with a single TB. Some tech advice on plenums would be nice too.

Is there a good EFI site somewhere with a writeup about these things?

Also, I'm interested in figuring out the difference between injector positioning in terms of valve back VS throttle face.

Any ideas would be great.

Pete

Hi, Pete's mate here who unreasonably wants more HP in Gwendolyn for less bucks. Here I was just waiting till the money tree grew a few more leaves, and meantime Pete's trying to get the whole thing sorted for $2.63!! Pete, the esteem in which my wife holds you is rapidly rising thanks to these efforts.

As I'm a complete mechanical novice, I'll look forward to Pete translating your responses for me

There you are at last my friend. Nice pic. wonder who took that. lol.

BTW, for those interested I found this thread on shoptalkforums...

http://www.shoptalkforums.com/viewtopic.php?t=111649 

Seems quite cheap to put honda TBs on.

BMW bikes have a good setup as well....not sure of the model though??? Was there a post on here about this????

can you post a link to it Mick?

I can post a link....just remember the "search" button at the top of the page....I'm sure there has been more talk on the subject...most of it is excellent reading!!
http://forums.aussieveedubbers.com/viewtopic.php?tid=66946#pid628114 
Try that one for starters.I think it's what your looking for all in one post!!! Welcome "Pete's mate" !!! Welcome to the nuthouse....

you dont need quads only more things to go wrong this is what i did works well


http://forums.aussieveedubbers.com/viewtopic.php?tid=63561&page=1#pid624099 

vw54, we're looking for throttle response and the best possible breathing for the least cash. I had a look at your system. It's very well crafted. I'm just not confident that we could produce something as good as that on a budget and I'm also not confident that it would breath as well as quads. I know that single or double TB systems can get very close to individual TBs, but they need to be properly designed and extensively tested. Obviously we don't have the time or cash for either of these two things.

Mick, you don't still have that EFI system do you? If you did and were willing to sell, what sort of $$$ would you want?

BTW, thanx for the link. That thread is excellent. We'll definitely check out the gotech.

Nah...my kit went with the 1916 when I got the Subi in. The only kits I have here are Kombi 2L and a waterboxer system with aftermarket ECU which I'm keeping...

vw54, do you still have the spreadsheet that was mentioned in the thread you posted??

There's nothing wrong with runnng a single throttle body...like Dave said,it will work fine!! Quad throttles are %80 wank factor anyway...and noisy....K>I>S>S principal comes into play here...Keep It Simple errr..."Sir"/Stupid

Hi

This is a single throttle body system on Leigh Harris's bug prior to turboing the car. He went from using quads to a single and found only a very small power drop at higher RPM.

Its hard to see but he mounted a WBX throttle housing and used pipes to take the intake air to Berg manifolds.

Steve

No worries Dave, I plan to race with what I have until I can afford to get it right, I don't want to waste more money than I have to. Budget isn't even the secondary goal, but if there's ways to do things that work (with the emphasis on 'work') and are a bit cheaper then I'd be nuts not to do it.

BTW what are people's experiences with the various brands of after market ECU???

Cheers

Hi

I'm a fan of Autronic, but they are not the best when using a TPS (throttle position switch), they prefer MAP sensor input.

Steve

If its a 1600 then stay with carbs...................efi won't give you any more HP.

HeHeHr...thats the "wank" factor I mentioned earlier...The engne you do will still have 4 inlets,nicely provided for by a plenium chamber...If it's a nice torque curve you're after as well as top end revs then a longer intake is your answer to maximise your available torque.I have no problem with quad boddied injection,I've used both systems myself. A single throttle body is just a lot easier to do and faster to tune.

if torque is what you r after sorry to say.single is best. we have done so much testing it sux.
i am not going to get wrigth into it but the cfm of the throttles is the important thing to consider.
good luck i look forward to seeing some progress

be interested in talking about how to work it out westi. is there somewhere to look it up?

with some of the throttle bodys that you can buy some quote cfm figures,but not many.
for us it was trial and error.but in saying that there wasn't much error.no backward steps.overal power was down but the torque curves were always higher.
i will see if i can find some dyno runs to show comparisions.i can remember a few of the top of my head.
basically you are making an extractor in reverse,so that each port is helping the next to draw in it's charge.ie. 1 into 2 into 4.different lenghts of primarys and secondarys give different torque curves.
research wise we have had to do it all with dyno testing.as there is nowhere to find anything helpfull.
we started with a car that use to run quad 50 throttles,it had no torque or divability until 6000rpm.
we knew that the 50mm throttles would out flow the head because we had flow figures.cfm wise.
all tests were on the same engine
4 x 50mm throttle bodies.172kw @8600 107 mph on a 12.7
we went 76mm throttle it made 157kw but injectors maxed out.@7800. 109.9 12.4
next one was a 83mm throttle same plenuim with new injectors 157kw @7000 111mph 11.97
there are many different way's to aproach it.we just went back to basics.bigger is not always better.they were perfect (quad 50mm) for 8600.but your not driving at 8600.the engine didn't have the draw in standard form.without cams ,valves and compression.etc etc.
the car when driving before was horrible until around 6k then it came on slowly like a turbo car until the rite rpm had been reached.after the single was put on i can not describe the amount of torque it produced,but the car now fry's 5 out of 6 gears in the dry.he doesn't drive it over 2000 rpm in the wet.
the best way to have a go with a vw is to buy some pvc and plumbin two cadrons together.make them knife egde where they join like and extractor.
you can only learn so much with this ,but you can play with lenghts and pipe diameters.
with the honda's it was a new manifold each time.
we are about to start all over again now with a few more ideas in hand.
i hope this helps alittle.
and i hope it makes sence,i am pretty tired.
i will have a look see if i can find some pic's.

thanx mate, that's what I wanted to know.

I'd love to see some pics if possible.

I'd also love to know how you calculated the length of your primaries and secondaries.

What exactly do you mean by "knife edged joins"?

As per our design I was thinking belmouthed primaries running into a large plenum that goes across the top of the fan housing. What do you think of that idea? Am I completely off base?

no plenums.
as the air comes in it looses speed.
use a tapered cone.

here is one of the very first.


i will try to find some pic's that will help.
these are the knife edge.

Pete yr talking about CHEAP and then yr talking about Quads they dont mix
Quads is 4 times the price and the advantage is small

I mean i am the cheapest buggar in the land I like cheap i even used a S/H throttle body and gotan old magna dissy cut down I did used some new components but these are expected

So whats the car / engine yr building I think u will be more than happy with a single

Trust Brads ( Westie ) advice hes got lots of experience with making stuff he did most of my welding and fab i did the time consuming stuff like gringing n fitting your going TOO much into the science of it all

I do advise to buy the best putor ( ECU ) you can afford

http://www.maxracesoftware.com/pipemax36xp2.htm 

Get your self one of these and it will calculate the intake and exhaust lengths for you.,
and it even has some interesting dyno and 1/4mile simulation extras(although the power numbers are high)

$$$ will be spent on putors. no doubt there. Just trying to avoid wasted $$$.

I'm open to single. However, as I said before, everyone in competition is using quads on custom built NA systems. The only exception appears to be V8s at the drags, but they're mostly dinosaurs anyway.

The car in question is an Lbug. It will be used for khanas and possibly the odd rally. The idea is to get as much value out of a 1600 as possible so the owner (gwendolyn's master) can stay in the 1300-1599cc class and have fun but still maybe get a class win. Hence the need for good throttle response and a broad torque curve. BTW, he did his first handbrakey on the weekend and almost has the hang of it, too!

Thanx for the heads up on the program dangerous. I knew you had some tricks there.

Westy, thanx for the pics and the advice. It's fun coz it seem to be counter to what every manufacturer is doing. That said, the reverse collector/extractor design makes perfect sense. Keep it coming.

thanks dave
just got it.program.
haven't had a crack at it yet.i will wait for lunch.
any more like that out there.