Thanks Jason...my numbers were from your session.

That was with a damaged compressor wheel on your car at the time, right?

 

Nocab72:
On my old car, my Turbo II with a "big street-port" series5 engine with the Wolf3D I would run as high 16-18 degrees degrees full advance on leading with 15 degrees split @ 24-25psi with 116 octane. I tried dropping the split to 10 and it lost peak power(~25hp) *but* it did pick up hp at peak torque.
On pump gas (93-94) I would limit it to 18psi and would run 12-14degrees full advance depending on outside temps. A/F were allways kept in the mid 11's.

On my FD (stock engine & turbos) motor is happiest with 0 split during cruising and up to "0" boost.
At 16 psi it responded best with a 12 degree split and full advance is still low...I believe ~10-11 degrees.

On the PowerFC you could easily back off/add timing on one of the pages for the whole map and on the dyno it's easy to see where the motor is happier.

Just need to be careful with negative split numbers.

Good Luck.

 

Boostn7 check your PM.

 

how come increased split increases hp at high rpm's? shouldn't decreasing split at higher rotor speeds net more power since the rotor face spends less time around tdc?

 

for some reason (in my experience) the Wolf system does not make more power with decreased split. i had wolf before so i know first hand, but i know for sure that on the haltech and PFC decreased split makes more power at high rpms. FDracer you are right typically a decrease in split makes more power under WOT.

MWW

 

With my PFC, on my stock motor, I saw gains in hp down to 8 split... began loosing hp when I dropped to 6 split. Didn't try 4.

Rumored that there are additional gains @ 4 split and less, but I didn't have the ***** to try it on my motor...should have, was the last day the motor was in my car, new Pineapple engine came the next week...

I felt safe with 8 split and had picked up about 18-20rwhp dropping from 12 split, so I was happy.

K

 

>>I felt safe with 8 split and had picked up about 18-20rwhp dropping from 12 split, so I was happy<<

Hehe....you mean there's more power to be found in my stock motor/turbos !!!!

It's been a 12 and haven't had a chance to lower the split since I was waiting to jump on the dyno.

Nocab72: at what boost did you find that gain? what was your advance on leading?

Thanks,

 

Boostn7 - My timing was tested first on the street using the Blitz PowerMeter, then on the dyno to confirm the results.

At 10psi I picked up 7rwhp going from 12 to 10 split.
At 10 psi I picked up another 7rwhp going from 10 to 8.

At 16psi I picked up 9rwhp going from 12 to 10split.
At 16 psi I picked up another 10rwhp going from 10 to 8.

For those tests, Leading was a max advance of 18 degrees @ peak torque @ 10psi and a max advance of 14 @ peak torque @ 16psi.

Just a reminder this was on a (worn out) stock block with GT35/40 bolted to it.

K

 

NICE !!!!

I see 10's on stock motor and turbos.....and slicks

Thanks Nocab72

 

i don't understand how you can start losing hp at a certain point of reducing split. did you guys tune your split vs. rpms, or was it constant throughout? i could understand how more split at lower rpms could result in more complete combustion and hence more power. but as rpm's increase, gradually reducing split should net more power. the way i see it as rpm's increase the rotor face sweeps through the two plugs faster and faster, thus the need to reduce split at higher and higher rpms. what is going on mechanically that i'm missing, where increasing split actually gained hp?