How Much RWHP is too much???

onerareviper

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Viperholics,

On the street, with street tires, how much RWHP is 'too much'? I have a '98 GTS with 440 RWHP and 3.73 gear. I feel I am at the HP limit with the 3.73 gear (and still hook up). What do you guys think the limit is using a 3.07 stock gear? Are these 600+ RWHP Vipers usuable on the street, or is it just massive wheel spin? I know they kick as* at a 1/4 mile track, but what about real world driving? Power is useless unless you can plant it!!

Thanks for any opinions......

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tattooed

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hahah. you can never have enough.

i suspect that it would be tough to build a *streetable* engine/car putting down more than 1500rwhp though.
 

treynor

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Gross oversimplification:
Because street traction depends heavily on weight transfer, the answer is it -really- depends on the shape of your torque curve. A relatively smooth, upward-sloping torque curve is ideal -- you get weight transfer in time to supply the traction you need. NOS and turbos are hardest on traction, because they tend to deliver large torque increases all at once. Certrifugal superchargers work really well on the street. On the dragstrip, running slicks, big low-end torque is best because it helps you launch. There, NOS or big displacement is king.

As a data point, I was able to get traction through 1st gear on my RT/10 when it had 515 RWHP/525 RWTQ. However, with a 100-shot I'd spin in 1st and (usually) 2nd.
 

MES

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Treynor is right, but it also depends alot on the temperature. This is what I have found. By easing into the throttle, trasfering weight to rear and not going WOT before 20 MPH:

below 50 deg my tires spin in 1st with just the motor no matter how softly I ease into the throttle

70 deg no tire spin in 1st with motor but I get alot with nitrous

85 deg no/minimal tire spin in 1st even with nitrous

When I say tire spin I don't mean 10 feet or a chirp. I mean tach jumps from 3,500 to 5,000+ RPM and car goes sideways weeeeeee
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I can also spin in 2nd (about 100 feet @ 65 deg) with nitrous but only with a hard shift. Without a hard shift I don't spin at all in 2nd and this is with 580 rwhp.

So I would say on a hot day 80-90 deg the limit is 550-600 rwhp in 1st gear with proper driving. You could do some calculating (using 550-600 rwhp in 1st as a base) for the gearing ratios in 2nd-4th and determine the max HP (torque really) for the higher gears before loss of traction. Or better yet, modify your car and find out for yourself
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BTW this is with a stock 3.07 and I have no wheel hop
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MtHam ACR

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There was a world-class race driver (sorry, his name escapes me) in the 70s who said he'll have enough horsepower when he can lay rubber from one turn-exit to the braking-zone for the next corner ;-) (or something along those lines).

Eric
 
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I have around 550 to the ground. It is streetable, but can get silly real quick if you are on street tires. First and second is a joke if going WOT. 3rd gear has a little spin or wheel hop, but if you can learn to drive the car, it is a lot of fun.
 
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onerareviper

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Viperholics,

Thanks for all the replies - keep'em coming. I like what Treynor said about the Torque curve - nice and smooth is best to keep wheels planted (Weight transfer). Looks like 550-600 RWHP with stock gear is do-able (traction wise) on the street (Warm/hot days). IMO, 0-100 MPH is where your at 95% of the time on the street, and why waste thousands of dollars if you can't hook up until 80 MPH+? (For street drivers like myself). If you can't go WOT until 3'rd gear, you are only utilizing most of the high $$$ HP from 3'rd gear forward when WOT. What about suspension mods? What mods can be done to help plant the rear tires? Seems like that would be money well spent.

P.S. - With the extreme price of mods, I can't afford experimentation.
 

TOOOFST

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A good question.The quality answers given get you to better questions like How fats your wallet? and How fast you need to go?
If you haven't got beat on the street,and don't hang around with Supra guys,a 440rwhp Vipers all you need!
 

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