Declutch, measure coast-down loss then add to the wheels figure to get flywheel. The dyno guy that operates the one I use has run many engines on an engine dyno then installed them in cars and run them on the chassis dyno. The numbers always come out close. ]]> John Dixon 2009-06-07T04:06:17-08:00 http://forums.nicoclub.com/zerothread?id=427730;postid=4814974#4814974 but how can they kQuote, originally posted by John Dixon Yes, it's crank HP, I never quote wheel HP, it's meaningless. Changing tyre pressures, running in different gears, strapping the car down harder can all change the wheel HP figure significantly but if you do coast down properly you'll always get the same crank hp figure.but how do you calculate what is being lost through the drivetrain the measurement is still being done at the wheels... Quote, originally posted by John Dixon raquo;
Yes, it's crank HP, I never quote wheel HP, it's meaningless. Changing tyre pressures, running in different gears, strapping the car down harder can all change the wheel HP figure significantly but if you do coast down properly you'll always get the same crank hp figure.

but how do you calculate what is being lost through the drivetrain? the measurement is still being done at the wheels... ]]> Aus450zx 2009-06-06T23:59:39-08:00 http://forums.nicoclub.com/zerothread?id=427730;postid=4814621#4814621 i had been told in past that the plenum of the engine should always be double the engine's displacement...dunno how true that is with ITBs tho. Carl H 2009-06-06T21:24:29-08:00 http://forums.nicoclub.com/zerothread?id=427730;postid=4813747#4813747 The injectors are Bosch 440cc top feeds (type 3 multi jet).Yes, it's crank HP, I never quote wheel HP, it's meaningless. Changing tyre pressures, running in different gears, strapping the car down harder can all change the wheel HP figure significantly but if you do coast down properly you'll always get the same crank hp figure.Cheers for the pics on the intakes. I'm actually going for something similar to either the LT5 pic or the VG30DETT setup depending on what intake lengths turn out to work best. I'll change it all when the new 52mm throttles go on. I'm hoping most of the restriction turns out to be in the 2.5" ducting feeding the box as there is a resonable x-section area inside the box its self. Yes, it's crank HP, I never quote wheel HP, it's meaningless. Changing tyre pressures, running in different gears, strapping the car down harder can all change the wheel HP figure significantly but if you do coast down properly you'll always get the same crank hp figure.

Cheers for the pics on the intakes. I'm actually going for something similar to either the LT5 pic or the VG30DETT setup depending on what intake lengths turn out to work best. I'll change it all when the new 52mm throttles go on.
I'm hoping most of the restriction turns out to be in the 2.5" ducting feeding the box as there is a resonable x-section area inside the box its self.
]]> John Dixon 2009-06-06T14:19:14-08:00 http://forums.nicoclub.com/zerothread?id=427730;postid=4793639#4793639 bhp = brake hp = crank hp.impressive numbers none the less. impressive numbers none the less. ]]> Carl H 2009-05-30T07:37:41-08:00 http://forums.nicoclub.com/zerothread?id=427730;postid=4793599#4793599 Nice thanks for reminding me, the GTiR would be a good start but the Corvette style plenum would be ideal for John to clear the hood/bonet Bart 2009-05-30T07:04:27-08:00 http://forums.nicoclub.com/zerothread?id=427730;postid=4793076#4793076 Quote, originally posted by Bart Gee mate it sounds great. I can certainly live with that noise for a while.Yeah the air box does look restrictive, you could go for a twin plenum set up similar to what the straight 6 GTR's use. (but the GTR uses a single plenum of course) kind of imagine 2 GTR plenums with 4 intake tubes on each side.Have you seen the factory intake setup on a Nissan Pulsar GTIR It's pretty much like that too... (but obviously sized for boost) You'd build a setup like this much with a wider plenum to fit between the V. Check out these pics:Then I remembered the Corvette LT5 engine and this engine's intake design wouldn't work too badly designed for ITBs: Quote, originally posted by Bart raquo;Gee mate it sounds great. I can certainly live with that noise for a while.
Yeah the air box does look restrictive, you could go for a twin plenum set up similar to what the straight 6 GTR's use. (but the GTR uses a single plenum of course) kind of imagine 2 GTR plenums with 4 intake tubes on each side.Have you seen the factory intake setup on a Nissan Pulsar GTIR? It's pretty much like that too... (but obviously sized for boost) You'd build a setup like this much with a wider plenum to fit between the V. Check out these pics:

Then I remembered the Corvette LT5 engine and this engine's intake design wouldn't work too badly designed for ITBs:

]]> Mettler 2009-05-29T22:23:33-08:00 http://forums.nicoclub.com/zerothread?id=427730;postid=4792592#4792592 Gee mate it sounds great. I can certainly live with that noise for a while.Yeah the air box does look restrictive, you could go for a twin plenum set up similar to what the straight 6 GTR's use. (but the GTR uses a single plenum of course) kind of imagine 2 GTR plenums with 4 intake tubes on each side. Yeah the air box does look restrictive, you could go for a twin plenum set up similar to what the straight 6 GTR's use. (but the GTR uses a single plenum of course) kind of imagine 2 GTR plenums with 4 intake tubes on each side.

]]> Bart 2009-05-29T19:57:33-08:00 http://forums.nicoclub.com/zerothread?id=427730;postid=4792307#4792307 its worth at least 10HP if you drive on the right hand side of the carPretty impressive numbers... 450HP should be EASY, maybe you'll be knockin on 500's doors... I would say most of that comes from the cams...What size injectors did you go with, if I recall you went with some top feeds. Pretty impressive numbers... 450HP should be EASY, maybe you'll be knockin on 500's doors... I would say most of that comes from the cams...?

What size injectors did you go with, if I recall you went with some top feeds. ]]> elwesso 2009-05-29T17:43:53-08:00 http://forums.nicoclub.com/zerothread?id=427730;postid=4791872#4791872 Quote, originally posted by DriftingisLame Man that is awesome, but how are you coming up with a BHP figure This is on a chassis dyno is it notGood work!-MaxBecause the "b" is for British Horse Power, duh! Quote, originally posted by DriftingisLame raquo;Man that is awesome, but how are you coming up with a BHP figure? This is on a chassis dyno is it not?

Good work!

-Max

Because the "b" is for British Horse Power, duh! ]]> SuperHatch 2009-05-29T15:14:59-08:00 http://forums.nicoclub.com/zerothread?id=427730;postid=4791362#4791362 Man that is awesome, but how are you coming up with a BHP figure This is on a chassis dyno is it notGood work!-Max Good work!

-Max ]]> DriftingisLame 2009-05-29T12:22:46-08:00 http://forums.nicoclub.com/zerothread?id=427730;postid=4791263#4791263 Managed to get a quick trip to the dyno today to sort some running in mapping but unfortunately my clutch release bearing siezed on one of the run downs so had to cut the session short.Didn't even get any mapping done, just enough runs to establish 2 things really: First that the fuelling is still too rich but OK to run for now.Second that the airbox/intake hose combo I have is too restrictive. Didn't manage to isolate which part due to the problem above, very frustrating.Results so far, with air box lid on, ~350bhp. With lid off 420bhp @ 7.5k (on the current rev limit). Not too bad for such a rough, guesstimate tune, hopefully a bit more to come.I think I may have been a little conservative on the cams, at 2500rpm it's making 300ft-ibs :D Didn't even get any mapping done, just enough runs to establish 2 things really: First that the fuelling is still too rich but OK to run for now.
Second that the airbox/intake hose combo I have is too restrictive. Didn't manage to isolate which part due to the problem above, very frustrating.
Results so far, with air box lid on, ~350bhp. With lid off 420bhp @ 7.5k (on the current rev limit). Not too bad for such a rough, guesstimate tune, hopefully a bit more to come.
I think I may have been a little conservative on the cams, at 2500rpm it's making 300ft-ibs :D ]]> John Dixon 2009-05-29T11:45:07-08:00