Sorry, been off the net for about two weeks. Anyways, I was looking through the old messages, and saw your response where you talked about your power to the wheels, saying 80-100. Was that in KW or HP?
HP. The 80 was taken on a portable water-brake style dyno in Riverside CA. the 97 JIS HP reading was from a stationary Bosch Eddy Current Dyno. It gave a reading in KW, which was corrected to standard conditions and to JIS HP. I think Japanese Horses are smaller, though. ;-) After looking at the conversions, though, I noticed the Dyno operator took a point below where I was making top KW, and if he had taken that, I would've run 101 JIS HP (On a 2 litre Fairlady Z!) His comments were that they normally come in around 70-80 JIS HP, stock. This was also the comment I heard in the states, that stock 240's run around 80 HP at the rear wheels, stock. This number really gives credit to guys who legitametly have a rear-wheel number above 150, as this truly represents a DOUBLING of available HP! Remember that I said the number was not as important as the RELATIVE CHANGE you see. Many people have the misconception that the REAR WHEEL HP on a 240 was 150, and it's just not the case. A car with 100-120 RW HP is healthy! More than that and you can actually SCARE some benchtop racers! I've had guys tell me that my HP has to be OVER 200 (HAAAH!) to get acelleration like I have. They REFUSE to believe it's "only" making 80, 120, 175, etc.
After you hang around and see the numbers a paradigm shift occurs. Ok, I've gone over the edge again. Sorry! Hope I answered your q!
RE: we always have long winded responses on HP....
Actually, I can shed some light on 240-280 stock hp at the wheels, as well as modified. The readings you were getting had to be something different from SAE HP ratings. But what I don't get, is a HP is the same no matter what, anyways, I don't know. A stock 240, in good tune, will put 110-120 to the ground, through the wheels that is. These figures were measured at the former Performance Chassis Dyno in Greenville S.C.,(now closed). If you look on zhome.com, under the modify for hp section Keith Thomas,(I think that is who it was), anyways, he did some comparison of headers with a stock spec 240 motor, and came out a right near and slightly more than what I said above, but those were engines getting ready for ITS racing, ie in a perfect state of stock tune, with an free exhaust.
A 280 motor, in the Z body, will put about 125-135 to the wheels. Sometimes more, but usually with mods. Now, the mod category, gets up to 200 for NA, and 450 for turbo,(the owner of the dyno, Dave, 19lbs boost, hi octane gas, ~350 on pump and less boost).
Since yours is a 2.0 fairlady, it seems reasonable to get right near 100 at the wheels. but only if it is a really good stocker. if you have done some work to it, i would say you should get more. Mine is putting about 175 to the wheels, and traction is a problem. in a 2300lb car, it is a lot of power, and outruns about everything on the road. i am in the process of putting a suspension from a former ITS car under it so it can turn like it can accelerate.
Thanks for the response, I was just wondering. 80hp is too low for a stock 240. it should see at least 100-110.
yes, even the dyno operator said there was a problem given the readings on the 4-gas. I changed the pump position and never dynoe'd it again, but the difference was dramatic: Pulled clean to 700 rpm after repositioning the pump, where before it would start to stumble at 5500. I guess I should've mentioned that. Most of the dyno guys I talked to referred to daily driven stock, bring-it-in-off-the-street 240's with tired motors. Something else I should've mentioned. This leads to the engine "freshening" argument: take a beat stocker, do a stock rebuild and find more performance. Not many people I know have a fresh 2400 to start their plans with, it's usually beat. Your numbers look reasonable to me, given fairly recent rebuilds and proper break-in. I still stand by my general premise of baselining the motor and then comparing 'before' and 'after' readings for a 'relative' improvement comparison. It's the only way to see what's helping or hurting, like in the link you mentioned.