The Cappa Is Back On Gas :-)

Post by **Coops** » Sun Apr 24, 2011 8:02 pm

installed all the nitrous gear back in the cappa today,
didnt have time to do any testing so fired a 100 jet into the nitrous pulsoid (50bhp) and a 35 jet into the fuel pulsoid,
quick trip up a local private road im allowed to use and Blimey it never pulled like that on a 50 shot before, made me

from ear to ear,
god knows what you did to the pulsoids Pel but shes a different car on gas now mate,
at WOT its running Rich which i think is the safe way to be at present (0.85 lambda on gas) im tempted to try a bit more gas, oh that was on a 1200psi bottle pressure.
how far before i need to retard and change plugs? didnt think i would like nitrous again

mgbv8 · Post by **mgbv8** » Sun Apr 24, 2011 9:30 pm

Well done dude!!

At that bottle pressure you are way rich.
What fuel pressure in the rail??

Drop the bottle pressure to 900psi for the next test so we can see how that changes the readings??

Make sure the bottle is as full as poss though so pressure drop does not come into the equation. Make sure you log bottle pressure before and after the test run..

On the 4.6 you can pretty much stay at stock timing for a 100 shot based on my own results. To be honest I can run a 300shot on 28 degrees btdc or 24 degrees btdc and still see the same track times..

That is something you will need to play with yourself.

Stock plugs will be ok (depending on your ign system) up to a 150 shot. Over that and you should think about B8ecs plugs.

Are you still running cast pistons??

Re the nitrous and fuel solenoids.!
All I did was build them and set them up as they should have come to you from the makers ?????

Pel

Post by **Coops** » Sun Apr 24, 2011 10:03 pm

Hi Mate,
cheers for the reply,

Fuel rail psi = 36psi (efi bosch 044 motorsport fuel pump)
ignition system: = fully mapped crank trigger ignition system with 8mm mallory pro sidewinder leads, ford coil packs x2 ngk stock rv8 plugs? 6's?.

yup still running cast mate cant afford forged ones

any other info you need?

stevieturbo · Post by **stevieturbo** » Sun Apr 24, 2011 10:52 pm

Is that sort of AFR considered safe for Nitrous ?

n/a it would be for sure.

With boost, no way would it be.

I'd guess Nos would be somewhere in the middle, maybe edging towards boosted AFR's ?

mgbv8 · Post by **mgbv8** » Mon Apr 25, 2011 6:10 pm

stevieturbo wrote:Is that sort of AFR considered safe for Nitrous ?

n/a it would be for sure.

With boost, no way would it be.

I'd guess Nos would be somewhere in the middle, maybe edging towards boosted AFR's ?

This is always a subject great debate Stevie!!
I tend to rely on plug readings as afr on nitrous can not be taken as gospel eh?

This is where the dyno can help iron out the finer settings on my carb setup.

As a side issue, what sort of afr would we be looking for with a blower on a 4.6 doing say 8psi ??
I need to learn about this stuff now I reckon

stevieturbo · Post by **stevieturbo** » Mon Apr 25, 2011 7:03 pm

mgbv8 wrote:
stevieturbo wrote:Is that sort of AFR considered safe for Nitrous ?

n/a it would be for sure.

With boost, no way would it be.

I'd guess Nos would be somewhere in the middle, maybe edging towards boosted AFR's ?

This is always a subject great debate Stevie!!
I tend to rely on plug readings as afr on nitrous can not be taken as gospel eh?

This is where the dyno can help iron out the finer settings on my carb setup.

As a side issue, what sort of afr would we be looking for with a blower on a 4.6 doing say 8psi ??
I need to learn about this stuff now I reckon

Depends on intake temps, compression ratio, type of blower etc

Not all boosted systems are as efficient as others. Generally speaking an efficient setup with relatively cool air, high 11's would be safe for only 8psi.

With a hot air rootes design...richer.

I run my own at lowish 11's or high 10's
Ive no desire to blow it up, and running leaner would have only a very very very small benefit on performance.

But EGT's and power may dictate different AFR's Only dyno testing would reveal the optimum.

I dont do dynos, so I play safe.

Post by **Coops** » Wed Apr 27, 2011 1:05 pm

Did another brief test today,
bottle pressure was just over 900psi, (not sure on weight yet have to remove the bottle and weigh it)
set the ramp time to 3 secs start at 25 shot building to 100% (50 shot)
car accelerates well from standing start, BUT as you get to 2.5k rpm it lights the street tyres up and spins em

also lambda didnt really change, stayed around the 0.85 range at WOT, and bottle pressure had dropped back to 900 psi when i checked,

Post by **Coops** » Wed Apr 27, 2011 2:40 pm

6lb gas in bottle.

mgbv8 · Post by **mgbv8** » Wed Apr 27, 2011 5:45 pm

You having fun mate ??

Post by **Coops** » Wed Apr 27, 2011 5:53 pm

just a bit

im tempted to up her to 75 shot

mgbv8 · Post by **mgbv8** » Wed Apr 27, 2011 5:56 pm

ADDICT ALERT !!!!

Post by **Coops** » Wed Apr 27, 2011 6:28 pm

I know mate its bad news,

how far can i push these NGK 6's?

kiwicar · Post by **kiwicar** » Thu Apr 28, 2011 9:24 am

"car accelerates well from standing start, BUT as you get to 2.5k rpm it lights the street tyres up and spins em "
Pull away in second???
Best regards
Mike