think they'll be worth 15 rwhp??

noslow5_0

New Member
Nov 7, 2003
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dallas tx.
my current combo made 260 horse/ 290 ft. lbs. of torque and i was looking to make about 275-280 horse an about 300-310 ft. lbs of torque... so for a last attempt to gain a few horses before the power adder im gonna put under drives, electric fan an 1" intake spacer on it... think itll be attainable??
 
Intake spacer wont do crap except add another 1" to an alrerady long runner intake. Scratch that. U/D are work 5-8rwhp. Elec fan isnt worth much, maybe 2-3hp. I gained nothing with mine, but I didnt put it on to gain power. I think you should be at least 275rwhp. Is your tune off? Hows the a/f?

Mike
 
14 * i didnt wanna go any higher since its really hot out down in texas right now an detenation is no bueno... we did lean it out quite a bit from what i had it at... gained 10 horse an 15 ft. lbs. of torque from it...
 
Michael, I gained nothing on the dyno with an electric fan. Long story (and too lazy to type :)) but it wasn't a 100% apples to apples comparison, but close enough. Track showed no gains other than being able to keep it cool while idling waiting on line to make a pass.

noslow, so your a/f is 12.3:1 now after elaning it out and gaining 10hp? Lean it out a touch more then and try more timing and run 93. You'll need a 130a alternator and 4g wire/fuse kit also.
 
Potential gains on tuning depend on the a/f ratio associated with your runs. For most of the naturally aspirated set ups I've seen, each point richer than safe optimum (around 13:1) gained about 8-10 HP. So, if you were around 11.5-12:1 a/f and you leaned it out to around 12.5-13:1, you'd likely pick up 8-10HP at peak.

Grn92 - I know what you mean about apples to apples. Measuring the actual impact of any one change is definitely an art/science combined. It's really hard to do effectively and accurately. But all I have to do is hold that fan/clutch assembly in my hand and I know I'd rather not be asking the engine to spin it. But who knows. When I went back to the dyno to tune, I had removed the stock HO headers and added FRPP shorties, and I (for grins) dumped the dino oil, and added a crankcase of Amsoil. Ambient temps were almost identical - 40F and low humidity/high pressure. We lost 3HP. I think the moral of the story is that most dynos aren't able to achieve repeatable results with that level of accuracy. I've got a feeling, notwithstanding their advertising to the contrary, that if they're within 5% repeatable, you're doing great. Heck, I've seen tests where one click tighter on the tie down straps added 10HP to the readings. Well, with that kind of variability, when you're looking for 3 or 4HP, it's kind of like looking for the proverbial needle in a haystack. And they keep moving it in the haystack.
 
I'll send you $5 if you become the guinni pig to do a before and after test on an sn95 electric fan :D I know I didnt gain anything noticable, but like I said, I put it on as a cooling mod, not a feeble 3hp mod attempt :D
 
Michael Yount said:
Potential gains on tuning depend on the a/f ratio associated with your runs. For most of the naturally aspirated set ups I've seen, each point richer than safe optimum (around 13:1) gained about 8-10 HP. So, if you were around 11.5-12:1 a/f and you leaned it out to around 12.5-13:1, you'd likely pick up 8-10HP at peak.

Grn92 - I know what you mean about apples to apples. Measuring the actual impact of any one change is definitely an art/science combined. It's really hard to do effectively and accurately. But all I have to do is hold that fan/clutch assembly in my hand and I know I'd rather not be asking the engine to spin it. But who knows. When I went back to the dyno to tune, I had removed the stock HO headers and added FRPP shorties, and I (for grins) dumped the dino oil, and added a crankcase of Amsoil. Ambient temps were almost identical - 40F and low humidity/high pressure. We lost 3HP. I think the moral of the story is that most dynos aren't able to achieve repeatable results with that level of accuracy. I've got a feeling, notwithstanding their advertising to the contrary, that if they're within 5% repeatable, you're doing great. Heck, I've seen tests where one click tighter on the tie down straps added 10HP to the readings. Well, with that kind of variability, when you're looking for 3 or 4HP, it's kind of like looking for the proverbial needle in a haystack. And they keep moving it in the haystack.

Someone beat me to it on the fan clutch assembly. Think there is "nothing" to gain in a track run at the very least with the clutch fan spinning away compared to a pass without a fan running period? This is why electric fans are so great, they don't have to and don't need to run all the time. They normally don't run on the freeway which saves gas mileage and in the winter you get the advantage of a faster warm up which knocks you out of the "closed loop" method faster and the other benefits from that are already known in an economical manner.
 
got a heavy duty fan clutch with stock fan an shroud... alt. is going to be upgraded before i do the fan... 89 and 93 octane is all i run... depends on gas prices around here right now... 1.90 for 89 and 1.99 for 93 is gettin up there for a 17 year old high school student that works part time at a bank... and send the 5 buxs this way
 
Things like underdrives and electric fans don't add as much HP as they do help the engine rev faster, which in the low gears they make a very good improvement. A dyno run is usually done in a high gear where the enigne is not accerlerating as fast. Reducing rotational mass and slowing down the rest helps alot.
 
More stuff here -- "They normally don't run on the freeway which saves gas mileage and in the winter you get the advantage of a faster warm up which knocks you out of the "closed loop" method faster". I don't see it working this way. The t'stat staying closed is what allows for warm up to occur. Air passing over the radiator because the fan is or isn't pulling it, doesn't significantly slow or speed up warm up. Also, it's a common myth - but engine coolant temp has virtually nothing to do with closed loop entry. All that has to happen is the O2's have to warm up enough to send correct signals. On non-heated O2's it happens in 90-120 seconds; on heated O2's it can happen as quickly as 15 seconds - all this even in cold weather.

"Things like underdrives and electric fans don't add as much HP as they do help the engine rev faster" - Semantics perhaps, but if all that was changed was a fan, and the engine is able to rev faster than it was with the mechanical, it's because more power is available to move the car. So, motors rev faster because they're making more power.

noslo- don't know your combo, but can you run 87? If detonation isn't a problem there's no benefit to running the higher octane; some myth at work there too about it being 'better' for the engine - in fact, the 93 octane is harder to ignite and burns slightly more slowly. For the summer, cut the timing back a couple of degrees and run 87. Mine runs with 18 degrees initial/34 degrees total on 87 octane with no detonation at all. Lucky me.