TheSamba.com :: View topic - Supercharging my 1600, Twin single Blow or Draw?

Wed Aug 13, 2014 11:18 am

Hey guys.

So I have read up and searched before putting this, but I am trying to find a decaffeinate answer.

I am going to get an AMR500 Supercharger for my 1600 with a 120 CAM (Stock heads) but I am trying to fathom if I should go down the route of;
*Twin 34 ICT with a Blow through System
*Single (likely stock or single ICT) Carb Draw though system?

I guess if I go with an ICT system it would look 'cool' But would it have any major benefit?

My Concern is losing pressure front between the gaps in the carbs like the the butterfly bushing etc..

But a Single carb would be less economical and much harder to setup and get a good idle from.

Any suggestion would be greatly appreciated.

Wed Aug 13, 2014 1:30 pm

An AMR500 isn't big enough to do much on a 1600.

ICT34s would not be up to the task, and Roots don't work well if there is a large volume between the butterflies and the valves.

Wed Aug 13, 2014 1:55 pm

Quokka42 wrote: An AMR500 isn't big enough to do much on a 1600.

ICT34s would not be up to the task, and Roots don't work well if there is a large volume between the butterflies and the valves.

Apprently from what I have read an AMR500 can do around 7PSI on a 1600 which is fine for me. Obviously I will have to drive it pretty hard.

When you say Roots don't work well if there is a large volume between the butterflies and the valves, What do you mean by that sorry?

Wed Aug 13, 2014 6:05 pm

Quokka42 wrote: An AMR500 isn't big enough to do much on a 1600

Erm...

http://shoptalkforums.com/viewtopic.php?f=3&t=145433

Wed Aug 13, 2014 6:30 pm

Amr500 supercharger works well on a 1600 untill about 1700 maybe littlle bit more cc not sure i've used an amr500 made 103 hp at the wheels but i used rebuild 1600 dp eagle 110 cam idf 40 carbs the engine ran like a dream i only switch out as i want more hp

Wed Aug 13, 2014 6:31 pm

not carbs sorry only 1 40mm carbs 8)

Wed Aug 13, 2014 7:15 pm

You will probably find you need to go with a tamer cam, W120 is way too much cam.

when I supercharged my 1776 even with a cam closer to a w110 it was choppy as f..k down low, ran beautifully with a stock cam though.

Thu Aug 14, 2014 5:04 am

Thanks guys, I thought a 120 would be on the big side but didn't fancy stripping it down, I was thinking a twin Ict blow through May help stumbling ?
If not at least it will make good top end power with a single stock carb ?

Thu Aug 14, 2014 5:26 am

An AMR500 displaces 500cc, so needs to turn at 1.6 times engine speed just to keep up with the average intake of a 1600. Trying to make boost at a decent engine speed will exceed it's capabilities.

Roots type blowers are generally locked to engine revs, and while you can use a blow-off valve, that is extremely unwise with a draw-through system, and doesn't compensate for the mixture distribution problems you will have.

If you don't intend to rev past about 4500rpm and use a dual blow through or throttle body system, you can make the AMR500 work, but I think you will realise why they aren't usually used above about 1300cc. There was a guy a number of years ago who used two of them. Not sure how he compensated for the pressure buildup on the "idle" cycle, though (remember a VW fires 4,3 on one cycle, and 2,1 on the other.)

Sorry to upset the bullshitters with stuff like maths. Sure you can spin an AMR past it's recommended limit, but you can't expect it to live very long, and dyno's often don't demonstrate driveability.

Thu Aug 14, 2014 5:38 am

I will be putting an rpm limit on about 4500 -5000rpm.

The amr has a max continus rpm of 16k so I'll over drive it 2:1 or maybe 2.5:1 this should give some decent boost enough for what I want.

Big question is single draw through or dual blow through ?

Thu Aug 14, 2014 8:52 am

Quokka42 wrote: An AMR500 displaces 500cc, so needs to turn at 1.6 times engine speed just to keep up with the average intake of a 1600. Trying to make boost at a decent engine speed will exceed it's capabilities.

I just knew you were gonna come in here and spout off some retarded shit on a subject you clearly have no experience with. :roll:

First off superchargers are not specified to pump air at some multiple of crank RPM, they are specified to move a certain amount of air per supercharger revolution. Since most of them contain gearing that will multiply the input shaft speed, your statement bears no semblance to the reality of the matter. Quote newton if you like, it's still a bullshit statement.

Second, even if you were right about the speed, your math is all wrong...

Quote: while you can use a blow-off valve, that is extremely unwise with a draw-through system, and doesn't compensate for the mixture distribution problems you will have.

OMG this is almost hysterically funny. Draw through blow off valve: explain to me how this device works, should be a pretty hilarious explanation. :lol:

Quote: Sorryy to upset the bullshitters with stuff like maths.

That reason right there is the reason you will never really experiment with anything to see if it works or not, if it's not in a science book it must be impossible...

Thu Aug 14, 2014 9:04 am

I used a amr500 for 15 thousand km no wear to the charger that i can tell and the engine was still 110% so for life span of engine who knows? Know 1.2nd its been done 10000time superchargering with amr500 and sc14 chargers. :lol: at the end of the day keep it around 7 to 10 psi you should 't have any probs along as the engine is strong. If i was you stay to one carb alot easyer :wink:

Thu Aug 14, 2014 9:09 am

Oh and as for the smart commet of the dyno and it been streetable it was easy to drive then the 1200cc with like 30hp i started with so yea very drivable :twisted:

Thu Aug 14, 2014 11:29 am

I understnd the vintage angle of an AMR charger. But I would opt for an Eaton M45 for a 1600 instead. - been there done that- at least on the tuning side on a customers engine.
Bottom line is, it works great, after A LOT of R&D. Would I do it again (?) NO! I would turbocharge it instead, for several reasons. One of them being fuel consumption. The charger draws too much and makes the engine real thirsty even at cruise.
T

Thu Aug 14, 2014 12:59 pm

Thanks guys so single draw through seems the way forward.

What sort of carbs are you guys using please?

Also when you say its thirsty, how bad are we talking?

Craig

Thu Aug 14, 2014 1:15 pm

Poraga wrote: I used a amr500 for 15 thousand km no wear to the charger that i can tell and the engine was still 110% so for life span of engine who knows? Know 1.2nd its been done 10000time superchargering with amr500 and sc14 chargers. :lol: at the end of the day keep it around 7 to 10 psi you should 't have any probs along as the engine is strong. If i was you stay to one carb alot easyer :wink:
Hey
What carb are you running and whats the spec of your engine (cam etc)?

Sounds like you have nailed it!

Thanks

Craig

Thu Aug 14, 2014 5:04 pm

Alstrup wrote: One of them being fuel consumption.

Did it have the bypass valve? That takes pumping losses from the charger out of the equation, I'm putting one from a Mini Cooper on my T4.

Thu Aug 14, 2014 8:30 pm

Hey mate i used a single 40mm carb ,110 eagle cam.And an upgraded pulley system. That about it in the way of after market goes well new gaskets n seals to. Every thing else was recon stock pistons etc there strong enough thought .All so upgrade your clutch while your at it. I went Kennedy stage 2 with it to be safe. 10 psi it fun to drive it its very streetable. didt over heat, quite good on petrol 7km per 1 ltr of fuel odd thats not on the dot. I drive my gard 90% of the time.Still was like new when i pull it out and sold it. I got 2800 dollars aus went to my new engine . :lol: any ways just pm me 4 any questions

Thu Aug 14, 2014 8:31 pm

Oh and the compression was set a bit higher then stock :P

Fri Aug 15, 2014 12:41 am

miniman82 wrote: Alstrup wrote: One of them being fuel consumption.

Did it have the bypass valve? That takes pumping losses from the charger out of the equation, I'm putting one from a Mini Cooper on my T4.
Yes. The guy even made a throttle dependant bypass valve to make it even more efficient on cruise and smooth power, which it really is, but it is just bad on fuel. 10 MAX 11 km/l even with a very easy foot. We used a modified 34 mm Pict caburettor.
The same type of engine, turbocharged will do 14-15 km/l with an easy foot. Granted, the turbo engine will not have the same amount of tourquein the 1500 to 2500 rpm range as with the blower, but I can live with that.

T