Gained only 3 horsepower?!
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Teching In
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Gained only 3 horsepower?! I have a 01 ss a4. Current dyno numbers are 340 hp to the wheels. 340 was obtained by installing american racing headers, K and N cold air system, 160 thermostat, 373 gears, and magnaflow catback exhaust. I just recently installed a rifled ported stock sized throttle body from Jannetti racing (also can be purchased from Mike Norris for those of you who recognize this name) and an SLP underdrive pulley. I thought for sure I would see more than 3 horsepower! I took the car to the same place I've had it dynoed in the past and it was a very cool day to make some runs. After reading an article in my July's edition of Camaro Performers magazine which documented this same install on an 01 z28 they recieved upward of 15 horses without a tune! What the hell. Luckily not a whole lot of money was spent and install was handled by a myself and a capable friend. Any insight would be great. Thanks guys.
First I've heard about rifled ported stock sized t/b's. I won't even get into the rifling part, but have to wonder why not port the t/b while it was out? This part alone I can see how no hp was gained.
The 3 hp you did gain surely came from the underdrive pulley alone. I'm not sure what the average hp gain is for an underdrive pulley, but I can't imagine it being all that much.
The 3 hp you did gain surely came from the underdrive pulley alone. I'm not sure what the average hp gain is for an underdrive pulley, but I can't imagine it being all that much.
Thread Starter
Teching In
Joined: Jun 2010
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First I've heard about rifled ported stock sized t/b's. I won't even get into the rifling part, but have to wonder why not port the t/b while it was out? This part alone I can see how no hp was gained.
The 3 hp you did gain surely came from the underdrive pulley alone. I'm not sure what the average hp gain is for an underdrive pulley, but I can't imagine it being all that much.
The 3 hp you did gain surely came from the underdrive pulley alone. I'm not sure what the average hp gain is for an underdrive pulley, but I can't imagine it being all that much.
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From: Illinois
....take it to the track? too many people look at dyno numbers, as long as you're getting better performance who cares.
Side Note: Is this new tb any larger than the stock one? if the sizes are the same, you would have probably have been better off porting and polishing the stock one. IMO
Also, those magazines tend to hide a lot of stuff. I remember reading an article 2 years ago where they took a stock 02' Camaro SS, got a baseline dyno and then put a full exhaust on it with LT's and picked up 45 rwhp. They didn't attribute how much power was picked up in the tune alone and other subtle things done during the tune....the magazine led you to believe that changing the exhaust gained that much power.
Side Note: Is this new tb any larger than the stock one? if the sizes are the same, you would have probably have been better off porting and polishing the stock one. IMO
Also, those magazines tend to hide a lot of stuff. I remember reading an article 2 years ago where they took a stock 02' Camaro SS, got a baseline dyno and then put a full exhaust on it with LT's and picked up 45 rwhp. They didn't attribute how much power was picked up in the tune alone and other subtle things done during the tune....the magazine led you to believe that changing the exhaust gained that much power.
You can't compare dyno results from different days. With no changes at all a dyno can change +/- 2-3%. That can be 8 or 10 hp, which can mask your true gains. The only way to compare dynos is if they are on the same day and close to the same time with the car on the rollers. Thats like getting a dyno and 6 months later dynoing again with no changes and getting 8 more or less horsepower and being surprised. Your not going to get the same results.
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its easy to understand magazines lie about dyno numbers and performance gain all the time, they are getting paid to advertise. those 15 horses probably came from a very aggressive tune and a splash of race gas. rifle porting eh? never heard of it. go with tried and true mods. ported heads and a bigger cam. i wouldnt buy anything from slp anyway, overpriced old tech.
I have a 01 ss a4. Current dyno numbers are 340 hp to the wheels. 340 was obtained by installing american racing headers, K and N cold air system, 160 thermostat, 373 gears, and magnaflow catback exhaust. I just recently installed a rifled ported stock sized throttle body from Jannetti racing (also can be purchased from Mike Norris for those of you who recognize this name) and an SLP underdrive pulley. I thought for sure I would see more than 3 horsepower! I took the car to the same place I've had it dynoed in the past and it was a very cool day to make some runs. After reading an article in my July's edition of Camaro Performers magazine which documented this same install on an 01 z28 they recieved upward of 15 horses without a tune! What the hell. Luckily not a whole lot of money was spent and install was handled by a myself and a capable friend. Any insight would be great. Thanks guys.
I have dealt with Ted on multiple occasions on multiple cars and wish you would have posted this before hand. Porting TB's often do not have a huge factor on HP, even on very modified motors and UD Pulley sometimes does by itself 3-5 hp but like said they dyno itself can very. Ted uses Dyno that is for Diesels and it has some varibles that make it very much like a Mustang dyno. So compared to a Dynojet you may see more.
Most times where you need more TB, generally your at the point where you need more intake and even with a FAST, a stock style intake has limits.
Since I am a CT local, most Dynojets in the area seems to be within 1% of his, and I have seen it with my own cars in the past Think he still uses the Superflow....
Just a FYI doing a U/D pulley, you were a spring swap away from throwing a cam in there. Sucks you may have to do the job twice...
As for the acclaimed hp there are generally other factors that may not be mentioned in the article, I will have to re-read it myself.
Adding swirl / turbulence at the head end of a dry-flow
manifold is going to give you nothing (at best). You can
hope that the rifling is only cosmetic. If you can hear it
whistle (like I have, with one of those dumb-*** vortex
inserts) than it's guaranteed* to be costing you airflow.
All the swirl you need, is made at the intake port ramp.
* liability limited to monies paid for advice
manifold is going to give you nothing (at best). You can
hope that the rifling is only cosmetic. If you can hear it
whistle (like I have, with one of those dumb-*** vortex
inserts) than it's guaranteed* to be costing you airflow.
All the swirl you need, is made at the intake port ramp.
* liability limited to monies paid for advice
Also look at your power through rpm range. You may have only picked up 3 up top but what about down low? And I am totally against adding any possible restrictions in my intake. Also was it hp at the wheels or at the crank the magazine was talking about . Most I have read post the projected numbers at the crank and not the tire so with parastatic loss u could be rite around what the mag said
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From: Lewisville, TX
Also just because you dont see any improvement in dyno numbers doesnt mean you wont see a performance gain at the track. My SS made 308whp on a mustang stock with a bad maf knocking its *** off. With a good maf and a ported throttle body it still made within 2-3hp of that (diff dyno diff day). But I dropped .4 off my e/t's.
Thread Starter
Teching In
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This is what the rifled throttle body looks like. It is actually called a V Maxx throttle body. Mike Norris from Indiana sells them as well. If the picture doesn't show in this post go to this website and read about it...
http://forums.corvetteforum.com/c6-t...9-shipped.html
You can't compare dyno results from different days. With no changes at all a dyno can change +/- 2-3%. That can be 8 or 10 hp, which can mask your true gains. The only way to compare dynos is if they are on the same day and close to the same time with the car on the rollers. Thats like getting a dyno and 6 months later dynoing again with no changes and getting 8 more or less horsepower and being surprised. Your not going to get the same results.
