blown 87

Yes, a lot of us have,some big time blower explosions, but how many have you seen that were dry types superchargers?

On a port type fuel injection motor with a supercharged running gasoline, how many of these have you seen explode?





Darg racers can break almost anything, you know that Brett, we are talking about a street car here that is stock with just adding N2O and nothing more.


What i have found out for myself, and what I have seen is that N2O is by far the biggest engine killer of them all. I have ran both and ran both hard.

I wish you all the luck in the world with your try at 1000 HP and 200 MPH, I hope you make it.

But there is no way that N2O is safer on a 928 than a twinscrew, centrifical, or a turbo.

Greg Nettles

mark kibort

hp for hp NOS is much safter than a blowers. NOS can give you the same Mass flow into the cylinder heads, and matched with fuel, you get a combustive force, of equal force as that created by a blower.

The big difference is that NOS is very cold, so you dont have the high temps, which in turn, can INCREASE detonation chances. nitrogen in the NOS, acts as a coushion and the combustion charge propagates at a more controled rate.

people blow motors when they make the engine do what it is not designed to do. Ive used NOS at rates well in the range of safety for the 928 engine. all of us know, all the stock components can handle HPs of near 500 at the rears without issues. any more than that, blower, NOS, ..... take your chances.

Getting mixture wrong is just as likly with a blower as it is with NOS. Way lean, is not an issue. in fact, thats how many aircraft decrease EGTs and CHT's. stoich is where you get big temp problems and likely, detonation. Its a pretty narrow range around 14.7:1

MK

mark kibort

hackers right about the dangers of unsafe or use without proper precautions.
the guy in the maxima was a fool, but we all can do stupid things. His design was bad all power to the system should have turned off with the ignition. a renagade bottle heater ,with the valve closed is a big deal. and his blow off valve didnt work either, (usually will blow before the bottle does at near 3000psi)
I think the danger we all face with NOS, if we use it, is a bad fuel mixture. in fact, full fuel loss for the NOS system will just make you have a rough running, lean engine which will have very cool EGTs and CHTs, especially with a high HP NOS setting. the main danger would be with a mild NOS shot, but the temp of the NOS could keep the combustion gases cool enough to run at Stoich without detonation . (calculated assumption) .

Mk

mark kibort

OMG!! just watched that video HACKER!! wow. what an idiot. what was that a fogger that was ported at the MAF, or just a big 200hp fogger that was going to the intake. intake was probably real hot, and when the fog hit the intake, it just exploded. i think this is proof that with big HP adders, you better do port injection of fuel and NOS.

Hacker's right. when you are talking foggers placed at the intake, bad things can happen. I was talking of only engine safety for the power added. I think the only way to avoid any of the chances for these types of bad things to happen is to run the NOS fogger like i did. with a dead pedal switch. that way, its not just activated with stagnant air just because you floor it! also, you got to get this fogger placed as close to the intake runners as possible. the 2 valve plennums are good for this. The vet is a little interesting, as the intake is usually plastic if i remember correctly. however, if the back of the valves are hot, and the charge can be ignited, it could go boom before the gas and NOS plus air, enter the cylinders.

good cautionary post. port NOS, or dry NOS systems probably are the only safe ways to do big HP shots.

off to watch the others!

pretty spectacular!

mk

Imo000

I blew my old Mustang, and '88, engine apart with a Paxton (9 years ago)! But I don't think it was due to the SC but maybe it did. The crank went downwards ripping the timing chaing apart, the SC pulley got under the car and lifter it twice before exiting at the back. When I pulled the engine half the main caps were ripped out of the block and I could see the treaded holes all busted up where the main cap bolts used to be. Also the block cracked in half and was held together by the engine mounts, heads and the lower intake manifold!


I would love to see what Brett can do with NO2 and a 928. Heck a replacement engine would cost less than set of pistond on a real dragster.

Imo000

NO2 can be dangerous cause it is contained in a pressure vessel. I bet you would find just as many occurences with natural gas or propane powered vehicles.

mark kibort

you know im a NOS fan, but i have to say, you dont have too many propane bottles with a bottle heater wrapped around them

Mk

Imo000

Doooh, you are right!

However as a kid in Europe I wathced my relatived every year during annual "pig slaughter" warm the propane tank with the torch to bring up the pressure in a half empty tank!

mark kibort

And then there is the story of the local nor cal shop guy, washing engine parts in gasoline and he is now dead! This car stuff can be dangerous..

Mk

hacker-pschorr

It's nice to see this stayed civil after Mark showed up .......j/k mark

I'm giong to talk to Tim and Todd about our next project:

7 liter with custom steele cylinders
Mark Robinson mid/rear/under/?? turbo feeding the inlet side of Twin Turbos from John Kuhn blowing into a Murf928 supercharger routed into a 928 Motorsports positive displacement blower.

Under Dave's blower will be 8 NOS injectors.

$5 says if we try hard enough we can blow a cylinder head clear over Lambeau Field from my driveway.

I say we fly in Randy to let him enjoy the initial test drive.

mark kibort

can i drive it once around laguna, just to put that evo in its place?

mk

Brett928S2

Hi Mark

Excellent posts from you

Its nice to see someone that actually understands how Nitrous works (cooling effect etc)

The bottle heater problem has been solved by Wizards of Nos ...they have designed an SPRV valve (Safe Pressure Relief Valve)....the way it works is that as the bottle temperature is raised and the pressure increases...the valve is set to vent small amounts of nos when an unsafe pressure is detected (normally 1050 lbs)...this is assuming the normal pressure switch has failed to cut off the bottle heater...
I KNOW this works as like an idiot I bought a NOS heater blanket and temp switch....it wasnt until I suddenly heard the gentle hiss as the SPRV was activating that I reasised the temp cut off switch was only working about one in 10 times
So rupture discs that were used in the past and emptied the whole bottle if overpressured are no longer used in the UK...
The SPRV just lets out small amounts of NOS until pressure is back within range

Hacker....you didnt answer...how are you getting round burning out clutches at a huge rate with a blower ???
Or are your 928 clutches different to Adrian Clarkes ????

All the best Brett

hacker-pschorr

I don't understand the question since I know people with stock N/A 928's that burn through clutches.
Actually it is, 1978-1986 928's have different clutches (superior performance) than the 87-95 clutches. So I guess if you are actually looking for an answer to your question, I would contact Dave Roberts, Tim Murphy or Carl Fausset.

The clutch in my race car is the original at 65,000 miles. These clutches are quite strong.

John Speake

[QUOTE=BRETT AINLEY]Hi

Regarding superchargers...Adrian Clarke in the Uk (who has a blown 928) has enormous problems with it blowing clutches...how do you cope with clutch burnout in the US ??
QUOTE]

Adrian overheated one clutch with some poor starts at the Pod.

Since fitting another more robust clutch no problems, even now having increased boost to 10psi

Hardly "enormous problems.".....

hacker-pschorr

Even been on a fishing trip? "Enormous" can vary quite a bit.