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Rotrex C38 on my 5.4L RV8
Posted: Fri Dec 23, 2011 8:39 pm
by daxtojeiro
Posted: Sat Dec 24, 2011 11:45 am
by ChrisJC
Looking forward to seeing the plumbing!
Chris.
Posted: Sat Dec 24, 2011 2:37 pm
by SuperV8
Nice, which trim c38 did you go for? are you going to intercool it? how much boost are you aiming for?
tom
Posted: Sat Dec 24, 2011 2:52 pm
by daxtojeiro
Its the 81 trim, so it should be ok for low levels of boost. 6-8psi, which should give me 450-500BHP quite easily.
Im going to be fitting a charge cooler. I want to make up some cardboard templates today to see if any that are available will fit in the engine bay.
Will just have to see how much pressure I can give it without detonation, as my compression is 10.44.
If I run into problems I will have to put a thicker gasket on it, but Im hoping it will be ok at 6ish PSI.
I will have to get a few pulleys for it so I can start off slowly and see how it goes.
Phil
Posted: Sat Dec 24, 2011 3:31 pm
by sidecar
Posted: Sat Dec 24, 2011 4:50 pm
by Cobratone
Two things Phil,
1, It'll all go horribly wrong!
2, It'll all go horribly wrong!
What are you doing about your clutch? Are you keeping it std or uprating it? I'll probably give you a call after boxing day and see how you're getting on,
Merry Xmas

Posted: Sat Dec 24, 2011 9:07 pm
by daxtojeiro
The clutch was all been sorted when I upgraded the engine.
The only weak part is the LT77, but if it breaks then I will get a T5 or Getrag slung into it.
What could possibly go wrong?
Please ring me Boxing Day, I will be round the Mother-in-laws

Phil
Posted: Sun Dec 25, 2011 11:17 am
by Eliot
Indeed. Although Phil knows how to creep up on a tune.
Get yourself a Bosch PCA12 for the chargecooler pump - fitted on all manner of cars, including the F150 lightning. I spent months pontificating over the best one to get and settled on the bosch.
http://www.mez.co.uk/turbo13.html
This is a fair price of ebay for one:
http://www.ebay.co.uk/itm/Ford-Focus-RS ... 2eb99b48ab
Posted: Mon Dec 26, 2011 9:27 pm
by daxtojeiro
I will sneak up on it quietly! Been reading your site for a while, will indeed be using one of theose pumps, thanks for the resource,
Phil
Posted: Mon Dec 26, 2011 10:07 pm
by Eliot
If you can possibly figure out a way of fitting an intercooler, then do it.
Chargecooler only any good when constrained by packaging.
You can see the many pages of struggle on mine. I found it difficult to get good info on core design and layout. Ironicaly I met the bloke who designed the jaguar XKR chargecooler setup after i had removed my one!
I didnt rate the knowledge of the people who supplied my cores, although the cores themselves were fine from a manufacturing point of view.
Posted: Tue Dec 27, 2011 9:45 am
by daxtojeiro
I really dont think I can get an intercooler past the rad to the front of the car, I will try with some pipe today.
So I've been looking at the ones available from ebay:
http://www.ebay.co.uk/itm/110601037754? ... 1423.l2649
or
http://www.ebay.co.uk/itm/Water-Air-Int ... 19c20e28a3
what do you think?
Phil
Posted: Tue Dec 27, 2011 9:07 pm
by Eliot
I dont know - and thats the problem; i haven't established what characteristics makes a good a/w cooler. My instinct suggests they are not that great though.
I would replicate or obtain a cooler that is shown to work effectively at your power level - by that i mean properly measured, not just some one-off pull on a dyno which is meaningless.
I found that a 10 second burst of boost would take several miles to get the water back down to normal. (of course all measured using temp probes in the coolant circuit). Big rads on the front didn't make a huge difference, but again, i may of made a mistake on the design.
The main thing i couldn't find out was what is the optimum design for a core - longer rows or the quantity of rows.
Posted: Tue Dec 27, 2011 10:51 pm
by SuperV8
Do you really need an intercooler if your planning on just 6psi with an efficient suppercharger?
Tom.
Posted: Wed Dec 28, 2011 9:59 am
by Eliot
SuperV8 wrote:Do you really need an intercooler if your planning on just 6psi with an efficient suppercharger?
Tom.
I would say yes, here's a graph from my turbo setup. I had temp probes on the turbo outlet and of course manifold inlet and ambient temp
At 13' ambient:

You can see that the turbo outlet was between 60-80'c (Yellow Line) and temps after the cooler between 35-45.(purple).
The top blue line is absolute pressure, which at 140kpa is indeed around 6PSI.
With 10.5:1 compression, you dont want to be force feeding hot air into the engine.
Hopefully phils supercharger should be inherently cooler, but my advise is to do something rather than nothing.
Posted: Wed Dec 28, 2011 10:26 am
by daxtojeiro
Yeah, I definetly want to add some cooling method this time. Ive done 8psi on an old 3.5 at 9.75:1 years ago and I didnt have anything on it then.
These days with EBay and the info on the net theres no reason not to have one. They are relatively cheap to buy too, its just getting it right thats going to be a pain! I may simply buy one and see how it goes, at least that way I have something to modify or to compare it all to. For the sake of £1-200 a throw I can get another one if I find its restricting or if its not efficient.
The trouble with designing my own is that theres not enough info on how they need to be designed as you say. The Americans seem to have been doing this for a long while, hence why I looked over there,
Phil