Porsche Enthusiasts Club Forum

Hi All

This is a post with a LOT of pictures about my recent 3 days in Doncaster having my new REVO system installed at Wizards of Nos...

I will post ALL of the pictures as they are in sequence but warning there are a lot...

I do NOT want this thread to become controversial, therefore I will ONLY answer technical queries from 928 owners or other Porsche owners that I KNOW actually own a Porsche !

All the best Brett

PICTURES...

BEFORE...

At WON (Wizards Of Nos).....

Stripping out old system and Plenum and Spider legs...

Rebuilding legs etc....

Legs with 8 more Venom Injectors drilled in underneath.... total Venoms now 16...

Next.... Before Nylon pipe...After A/N Braided...

Next..New X10 Pulsoids....plus the REVOS (silver oblong boxes)

next....final pictures including REVO control box (front centre...








I have some final wiring tidying up to do, but the system is tested and all working and its TOTALLY amazing to use

For those interested the cost was a little more than a 928 Supercharger kit would be...that includes all the parts and labour though.

As this is the first REVO system on ANY road car in the world, I will be VERY carefully increasing the power through the Revos a tiny step at a time....

All the best Brett

I'll put my head on the chopping block here having been openly sceptical of the claimed power of this system, possibly through ignorance of exactly how Nos systems work, but if you don't ask you don't know. I'm assuming the additional injectors(?) are there to allow the volume of nitrous to be increased and thus increase the benefits in terms of horse power.
I take it that the Nos is pressure fed being stored as a liquid but burnt as a gas so the intake side probably needs little if any boosting, but will the available power ultimately be restricted by the volume of gases the engine can flow? I'm not sure I'm explaining that very well but assuming that the intake side is under pressure, the higher the pressure or longer the duration of the injectors opening the more gas you can get in and theoretically increase the amount of HP produced. Does there come a point at which irrespective of how much you can feed in the size/lift/duration of the exhaust valve cannot cope and you reach a point of diminishing returns? Presumably you'd reach a similar point wth a forced induction engine as well.
Whats the difference between the blue and red pulsoids and why only 4 Revo's, what ever Revo's are, on an 8 cylinder engine.

Hi

Well at least you had the intelligence to ask all the correct questions

Which I will answer in this thread.....I have already said I will no longer post in the other thread, and I ALWAYS keep my word....

Ok...to answer your questions...

I will have to get pretty basic here so please forgive me if it sounds simple or condescending.... it is not intended to be...

Ok... an engine needs 3 things, Fuel, Air and a spark....

A Nitrous system needs Nitrous, EXTRA fuel and a spark

This is the difficult bit....you combine those two statements above and although they WILL run together, they CAN run separately...

Think of it like this.....obviously a normal combustion engine can run without a nitrous system...but a nitrous system can also run (almost) without a normal combustion system...

Therefore to some degree they run separately ....

Now back to your questions...

ALL the pictures you can see are parts of the Fuel system for the Nitrous...red pipes and Pulsoids = Fuel by the way...Blue = Nitrous

What you can NOT see is the Nitrous injection...which is deliberate as the Pro Race system is still fairly secret....

I can describe it though, at least roughly....it consists of some stainless/brass pipes drilled through the plenum from the underside and going straight across the interior of the plenum into the OPPOSITE side spider legs...

So if for example you sliced the plenum halfway down on the horizontal plane you would see 8 pipes going from opposite sides with some rather fancy ends, so the Nitrous when it is started by the controller...STARTS in the plenum legs directly...well past the MAF etc...

Regarding Nitrous, yes you are correct, it IS stored in my twin 15 lb bottles as a liquid at high pressure (950 psi) which when it is activated it changes to a gas (phase change) and releases the Oxygen into the cylinder at around 2.5 to 3 times the percentage of normal air, which is why the normal air entering the air filter, maf and engine is totally immaterial...

So to make my Nitrous system work in the cylinders, you NEED ....a LOT of Nitrous, a LOT of EXTRA fuel and a spark....and thats where the EXTRA power (hp) comes from....


Apologies if I simplified that too much but please ask any question on anything I did not explain well or at all lol....


Oops forgot to add... REVO = Rotary Electronic Variable Orifice ... think of it as a perfectly smooth electronic tap that can be turned on a little or a lot but absolutely smoothly...


All the best Brett

Thanks Brett, I think i almost understand the priciples now, look forward to seeing the results on a rolling road

Are you going to pay for it Lindsey? Might struggle to find a dyno that would put that on. If they would they would want a lot of money. Most dynos will only run up to 90mph & do power runs in 3rd. You can't run that sort of power until your in top & even then wheel spin will be a problem. I think the power will be limited by what you can put down. That means LSD & sticky tyres. Then you can have clutch slip/drive shaft failure. It's not that easy. The systems 2000hp capable. But what can you put down??????? Well maybe Brett cant answer that one yet as it's only just fitted. May need a taller diff. Should be fun finding out though.

Hi J.J

You have a very good point, locally to me there is only one dyno and they refused to run my previous 1000 hp capable system, they "said" that if anything hits 1000 hp the dynojet dyno redlights and shuts down to prevent damage.....I dont know how true that is but they will NOT allow me to run even when I offered to turn down the power to a couple of hundred hp over standard

I may well have to dig out my old G-Tech meter (not used for a couple of years) assuming it will work in Windows 7 lol.

All the best Brett

All the dynos I've seen have done power runs in 4th or 5th & Bretts car is Auto so only has 3speeds anyway. Certainly I've seen much higher speeds than 90MPH, the 7 was around the 140MPH mark on the rollers at Progress. The problem you'll have is A. Traction especially if the torque is spiky & B. given the toque peak getting enough load on quick enough as the power rises. This is a common problem with turbo type motors. Simon who dyno'd my 7 had a Lotus Esprit Rover V8 twin turbo on the dyno just before mine & every time the revs hit 2,500 the thing just lit up the wheels. Even with a cargo strap across the roll cage & a set of fork lift prongs on the back it still couldn't get enough traction on the rollers. At a guess this was around 350ish BHP, the problem gets worse with higher power.

Hi Jim

Mine is a 4 speed auto by the way, and it doesn't change into 4th until around 120 mph....if I hit the Nitrous at 120 mph its going to hit 160 plus VERY quickly
Maybe thats why they wont run it...

All the best Brett