41 replies to this topic

[uksurvivor]

but as one i am doing now is blow through fitting inter cooler

Care to share any build photos? Do you have a project link????

[Prawn]

I don't know what kind of dump valve you did use. Mine is a forge with a spring in it. The biggest issue is to get the right tension in the valve. You can change the springs and work with shims to setup the correct tension. The dump valve should open when there's a vaccuum in your inlet manifold. When the spring is too strong, the valve doesn't open and your rmp will rise very quick. If the spring is too soft, the valve will not close and you lose air and so you lose power. I found it not very easy to setup, it has to work perfect.

Sorry to bump an old post, but I've been thinking about different ways of blow through supercharging, and came across this this morning and had an idea....

Rather than using a conventional style piston bov, where the boost pressure pushes against the bottom of the piston, and it relies on spring tension and the smaller charged feed on top to remain shut.

Why not try using a forge recirc valve like the 007p? my audi runs a 007p valve, and the charged feed from the IC pipework actully goes into the side of the DV, not the bottom. This means that on boost, there is no pressure trying to force the piston open. It still takes its feed from the intake manifold in exactly the same way, but the end result is, that a much softer spring can be used, giving a much quicker DV response.



In that pic, the piston runs from top to bottom, when fitted to the audi, I tried running the DV both ways round. With the charge feed in the bottom, the DV was forced open and lost boost above about 10psi. with boost comming into the side of the DV, it holds boost fine up to 22psi, and still works perfectly well with a softer spring, so reacts quicker than if I were using a really tough spring.


Would this setup not work fairly well on a blow through charged A-series? it'd mean quicker DV response when letting off the throttle, and no worries about loosing boost

Both feeds on the forge are also standard 1'' by the way, so it should replace any other DV you may currently be trying.

Edited by Prawn, 07 May 2009 - 01:56 PM.

[Prawn]

Or what about an HKS SSQV style DV? they don't relpy on a vacuum feed to pull the DV open, the vacuum feed just activates it, and it realies on a pressure differential to remain open, so only stays open for the shortest time needed.


I can imagine a blow through charged A-series must make some seriously strange noises on over run!

[dougie1142]

This is an interesting topic, Agreed that the plugs look harder to change with the blow through, but also agreed the performance with a blow through does seem to make doing it worth while.....hmmmm

[Prawn]

it's got to be worth it just for the extra boost you can run.

going from 10psi on a suck through setup, to about 14-15 (I think this is what the bini's can successfully run with an IC) would bring about a massive increase in power!

[NDT]

blow through useing turbo carb withm odified plenum and bmw supercharger

Many thanks Stig - just what I imagined (only neater!) is it / was it yours?

no not mine but doing a similar build at the minute but injected

How are you sorting the crank pulley for the supercharger?
Are you running the same belt as the alternator or doing something else?
cheers
Nick

[Prawn]

from what I've seen, using the same belt for the waterpump/alternator/charger seems to work pretty well. I can't see any good reason not to do it that way.

Apparently, according to Remko who posted earlier in this thread, he gets about 7-8psi using the MPI lower pulley and standard bini charger pulley.

[magicbunny69]

Awwww man! All this talk of forced induction makes me want it sooooo bad! Think i'll still be sticking with my plan tho Prawn

[THE STIG]

blow through setup seen at the imm

supercharger goes into a intercooler directly below supercharger behind the subframe then comes out around the rad in to a turbo carb

Edited by THE STIG, 12 August 2009 - 03:21 PM.

[BoboGib]

Damn, you Mr Stig,

Think I know where all my money is going now.

[Prawn]

That van belongs to Remko who's posted on page 2 of this thread. I've spoken to him at length and it sounds like a REALLY nice installation, which I'm trying to adapt and copy myself!

[rammie2000]

Hi all

i'm bit late to react on this topic but i'm building my dream mini round nose flipfront (steel) fortec narrow kit,....
part of my dream is building a blow trough supercharged 1340 engine for it. i have the engine bored and so on but now i come to the supercharging part... i can not find exactly what i need (size and stuff) to build a blow trough charger... i now so this topic... can anyone make up a scheme or drawing or part list what to get how to place it and where for me? i do have the skills to do it for sure (i build cars and custom bikes) but i don't get the charging thing. where does the blow valve go? what blow valve do i need? and so on. hope this is not asked to much.
also can i convert my normal hiff 44 to a hiff 44 suitably for charging? (turbo spec)

greetings from belgium.