weird numbers, backpressure?
Thread Starter
TECH Resident
Joined: Aug 2008
Posts: 910
Likes: 0
From: Dubai
weird numbers, backpressure? Well I wont even mention the number "yet" lol, but I dynoed my TT 427 with 7PSI of boost (wastegate spring) and got a funny number.
Its worth mentioning though that:
- they were back to back runs,
- weather was hotter than I expected (mild sandstorm)
- non synthetic oil, im guessing synthetic itself should add a few ponies.
- engine had almost no break-in miles before this.
Numbers were still low. I knew before getting the car on the dyno that my exhaust is messed up, like it makes a funny (damaged?) sound and I never had the chance to swap it out.
Trashed that custom exhaust, and im running a stock Z06 exhaust for the time being (did not dyno with this exhaust), however im wondering how much of a difference could a PROPER exhaust do in my set-up say at 7PSI over the stock z06 exhaust.
FYI, turbo downpipes are 2.5" then step up to 3" and narrow down to 2.5" before entering the rear Z06 mufflers. Looking for a true 3inch exhaust.
Power gains? Examples?
Its worth mentioning though that:
- they were back to back runs,
- weather was hotter than I expected (mild sandstorm)
- non synthetic oil, im guessing synthetic itself should add a few ponies.
- engine had almost no break-in miles before this.
Numbers were still low. I knew before getting the car on the dyno that my exhaust is messed up, like it makes a funny (damaged?) sound and I never had the chance to swap it out.
Trashed that custom exhaust, and im running a stock Z06 exhaust for the time being (did not dyno with this exhaust), however im wondering how much of a difference could a PROPER exhaust do in my set-up say at 7PSI over the stock z06 exhaust.
FYI, turbo downpipes are 2.5" then step up to 3" and narrow down to 2.5" before entering the rear Z06 mufflers. Looking for a true 3inch exhaust.
Power gains? Examples?
I d want more info before going further.
Fuel, used, timing?, injectors size(duty cycle), pump(s), air intake......are you sure its not closing up? intercooler, ater/meth, auto,manual, gear used, dyno used.
Fuel, used, timing?, injectors size(duty cycle), pump(s), air intake......are you sure its not closing up? intercooler, ater/meth, auto,manual, gear used, dyno used.
Thread Starter
TECH Resident
Joined: Aug 2008
Posts: 910
Likes: 0
From: Dubai
fuel: 93 octane
timing: 15degrees (we can go two more degrees before it sees detonation
injectors: 95 pounders, no idea what the duty cycle was
bosch 455 pump
air-air intercooler
manual
can't remember what gear was used, but im kinda certain its not the 1:1 gear
dyno dynamics (although its calibrated to read high numbers)
timing: 15degrees (we can go two more degrees before it sees detonation
injectors: 95 pounders, no idea what the duty cycle was
bosch 455 pump
air-air intercooler
manual
can't remember what gear was used, but im kinda certain its not the 1:1 gear
dyno dynamics (although its calibrated to read high numbers)
TECH Apprentice
Joined: Mar 2006
Posts: 361
Likes: 1
From: australia
Back to back pulls, shouldn't change the output data,
if it does, some think wrong with engine or dyno...
It's notif this engine is a comp , race engine that needs time to cool down, ( ie, solid heads or block)
hotter air means the power will drop off a bit, but the correction factor with change it , and can show what it would make , in better condiftions...
what is the correction factor used ??
what was the a/f ?
synethic oil playing up?
your joking right ? in high powered N/A engines i see 10- 15 hp from say 20w - 50 oils back to 0w-30 syn oils
if you have tooo much oil , not enough oil, wrong sump , that may play silly buggers with you.
that "funny damaged" sound... where is it ?
not a turbine wheel damaged ???
not some junk left in the exhaust manifold ??
that engine, did it go more than 600 hp ?
will be sweet to see it under full power side ways up the highway...
if it does, some think wrong with engine or dyno...
It's notif this engine is a comp , race engine that needs time to cool down, ( ie, solid heads or block)
hotter air means the power will drop off a bit, but the correction factor with change it , and can show what it would make , in better condiftions...
what is the correction factor used ??
what was the a/f ?
synethic oil playing up?
your joking right ? in high powered N/A engines i see 10- 15 hp from say 20w - 50 oils back to 0w-30 syn oils
if you have tooo much oil , not enough oil, wrong sump , that may play silly buggers with you.
that "funny damaged" sound... where is it ?
not a turbine wheel damaged ???
not some junk left in the exhaust manifold ??
that engine, did it go more than 600 hp ?
will be sweet to see it under full power side ways up the highway...
TECH Apprentice
Joined: Mar 2006
Posts: 361
Likes: 1
From: australia
agree
hard to fault find with out more data..
backpressure, boost ,ignition etc, etc
DynoDynamics are very stingy dynos for bragging rights. Was it in "v8 turbo shootout" mode? If not the ramp rate for a turbo car can kill the reading. Also was the rpm taken from the roller or the sparkplug? That also can make a huge difference in the hp reading. Lastly is tire slip...hope the operator was well trained as a DD has a very different set-up for vehicle strapping...rear tires have to move up and into the small roller for traction. Great machines...but very "different".
