How fast/much power made on 3" downpipe? 4"?
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TECH Junkie
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From: Glen Burnie, Md
How fast/much power made on 3" downpipe? 4"? Wheres the bottleneck happen? I cant see being able to make more than 700 flywheel hp or so with a 3" downpipe. The small motors seem to wheeze out around there with the 2-3 L stuff
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TECH Junkie
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From: Glen Burnie, Md
If it was only that easy. I have several customers with 4 digit numbers that dont run those speeds in the 1/4. Just because you make a given HP number on a dyno doesnt mean Jack. Suspension, Weight, Traction, Tune Up, among other things play thier roles.
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TECH Junkie
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From: Glen Burnie, Md
I hear ya there, just trying to draw a comparison to number that Im used to seeing on my dyno. You cant say a 3" downpipe is good to 800 hp on dyno A that might be a "happy dyno" and expect it to be ok on dyno B necessarily.
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Verdad Gallardo I look at it like this. Turbos are made to flow a specific amount of Air ( lbs/min ) at a given Discharge outlet be it 3", 3.5", 4", or 5". A TC76 is rated for given HP potential with a 3" Discharge. The way I see it is that if you are chocking the turbo with the 3" DP then you are out of that turbo's effective efficiency range. A bigger DP is a band aid at that point.
If a car is happy with a 3" DP and 800rwhp on dyno A then whats the diffrenence in Dyno B? If it works it works. The only way to really tell if the DP is effiecient is to measure the Back Pressure. Dyno numbers are not gonna give you the info you need for that.
If a car is happy with a 3" DP and 800rwhp on dyno A then whats the diffrenence in Dyno B? If it works it works. The only way to really tell if the DP is effiecient is to measure the Back Pressure. Dyno numbers are not gonna give you the info you need for that.
I'm pretty sure one of Jose's customers car made 900+ and went 150+ in an lt1 car with a 3" downpipe, been a few years ago though, but if I remember correctly that car only had a 3" downpipe.
Different car, but my buddy's Evo with a 3" downpipe all the to the back of the car with a 44mm wastegate dump out the front has gone 157mph in the 1/4. Raceweight is about 2800 I believe.
Weight of the vehicle plays a huge factor in how much power it takes to run XXX mph in the quarter mile. For instance, most HP calculators will put me right at about 750rwhp running 142 MPH at 3800 lb race weight.
Very true. This is why I'd rather use a calculator off my ET/MPH to calculate HP rather than to actually get on the rollers.
What size was the discharge on the exhaust housing?
What size was the discharge on the exhaust housing?
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TECH Junkie
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From: Glen Burnie, Md
The ATI calculator seems to hold fairly well to flywheel numbers (and the comparison to the rearwheel number on our dyno parrallel well also), but the rearwheel calculators are f'ing worthless everyone Ive seen, they are all over the place.
@750 hp at 3600+ lbs on my dyno goes has been well over 150mph thats what dyno numbers are hard to talk about unless you know the correlation from that particular one
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TECH Junkie
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From: Glen Burnie, Md
I look at it like this. Turbos are made to flow a specific amount of Air ( lbs/min ) at a given Discharge outlet be it 3", 3.5", 4", or 5". A TC76 is rated for given HP potential with a 3" Discharge. The way I see it is that if you are chocking the turbo with the 3" DP then you are out of that turbo's effective efficiency range. A bigger DP is a band aid at that point.
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