LT4 Hp Numbers
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Instructor
Joined: Aug 2003
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From: Sydney NSW
LT4 Hp Numbers
Just read this on another site, how much truth is there in it?
The LT4 really can vary in Horsepower and torque. Like I said, the average one on the street comes in between 350hp to 360hp. We have tested over 125 LT4 units since 1996 and found that less than 25% of the units come in under 345hp. About 15% come in between 360hp and 375hp. About 10% range between 375hp and 385hp. 2% have been found to hit the very low 390hp range. This is all stock from Bowling Green. Keep in mind that the torque also increases too. One unit came in on the dyno at 392hp/426lbs-ft torque @5850rpm. Very rare but still present out there. This is why there have been reports of LT4s running with or past ZR1-LT5 cars over the years. Basically, the LT4 will out run the LS1 in 75% of all cases.
[Modified by CussCuss, 11:12 PM 3/2/2004]
The LT4 really can vary in Horsepower and torque. Like I said, the average one on the street comes in between 350hp to 360hp. We have tested over 125 LT4 units since 1996 and found that less than 25% of the units come in under 345hp. About 15% come in between 360hp and 375hp. About 10% range between 375hp and 385hp. 2% have been found to hit the very low 390hp range. This is all stock from Bowling Green. Keep in mind that the torque also increases too. One unit came in on the dyno at 392hp/426lbs-ft torque @5850rpm. Very rare but still present out there. This is why there have been reports of LT4s running with or past ZR1-LT5 cars over the years. Basically, the LT4 will out run the LS1 in 75% of all cases.
[Modified by CussCuss, 11:12 PM 3/2/2004]
Melting Slicks
Joined: Mar 2003
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From: Toronto ONTARIO
Re: LT4 Hp Numbers (CussCuss)
umm... interesting info. Id say fresh off the factory floor with 0miles they would dyno at 295 at the wheels. After the get loosened up and broken in maybe 300-310 rwhp. i personally think any dynos that vary really depend on maintenance and things like air temperature, altitude, humidity etc etc. I think a lot of people want their LT4 to be strong so theyll post BS dyno numbers.
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From: Kennesaw, GA www.96LT4.com
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Re: LT4 Hp Numbers (CussCuss)
That guy is from GA, sad to say....no way are LT4 cars gonna pull 350 RWHP without some help.
Drifting
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From: MCAA License to Kill
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Re: LT4 Hp Numbers (96LT4)
That guy is from GA, sad to say....no way are LT4 cars gonna pull 350 RWHP without some help.
But one point still made is that the LT4 engine can still vary between cars :eek: BK even said that his "new" LT4 in stock form just felt stonger than his last one :yesnod: Maybe there's at least something to that. He could have gotten a "normal" 350-360 CHP LT4 in the first one and now has a magical 390 HP one now :D :D
:jester :cheers:
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From: San Jose Pat Tillman - American Hero
Re: LT4 Hp Numbers (96LT4)
That guy is from GA, sad to say....no way are LT4 cars gonna pull 350 RWHP without some help.
What gives?! If we all agree our cars are somewhere closer to the 350hp (crank) range rather than the 330 GM quoted, he either has a ridiculous amount of drivetrain loss, or his car came *way* lower in HP from the factory than it was "supposed" to. If a car can come that low, why couldn't one come way high?
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Safety Car
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From: Hinckley Ohio
Re: LT4 Hp Numbers (Perfusion)
Actually I think most TRUE as from the factory stock LT4's dyno closer to 260-280 rwhp. Most who dyno at 300 rwhp stock actually have done some mods such as cat-back exhaust, open air filter housing, K&N, , hypertech, 160 stat, tb bypass, etc.
395hp from the factory :bs
395hp from the factory :bs
Melting Slicks
Joined: Apr 2000
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From: Northern CA
Re: LT4 Hp Numbers (Perfusion)
I wish I could remember his screen name, but I do specifically remember he listed his stock LT4 at 260(ish) whp when stock.
Safety Car
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From: Marianna FL
Re: LT4 Hp Numbers (JasonL)
260-270 on a Mustang Dyno would be about 295-305 on a Dynojet. My car dyno'd 284 rwhp on a Mustang Dyno with a cold air intake and no mufflers.
The 390 HP numbers are pretty hard to believe for a stock car. 300 RWHP is pretty common for stock cars.
The 390 HP numbers are pretty hard to believe for a stock car. 300 RWHP is pretty common for stock cars.
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From: San Jose Pat Tillman - American Hero
Re: LT4 Hp Numbers (JasonL)
I wish I could remember his screen name, but I do specifically remember he listed his stock LT4 at 260(ish) whp when stock.
That is No Go and he used a Mustang dyno whereas most people use a Dynojet. Most stock LT4s seem to produce ~300rwhp on a Dynojet.
That is No Go and he used a Mustang dyno whereas most people use a Dynojet. Most stock LT4s seem to produce ~300rwhp on a Dynojet.
Melting Slicks
Joined: Apr 2000
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From: Northern CA
Re: LT4 Hp Numbers (Perfusion)
Ah...I see. Why in the world would anyone use a Mustang Dyno, then?
Race Director
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From: Everyday you must choose between the pain of discipline and the pain of regret. Fredericktown, OH
Re: LT4 Hp Numbers (CussCuss)
Mine dyno'd 305 RWHP which is 360 using 15% drive train loss - and it only has bolt ons. I believe it was more than 330 stock, but some of those claims of being 370-ish seem far fetched.
Race Director
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From: USA. Northern Virginia
Re: LT4 Hp Numbers (Mikez40)
I would say it sounds true...not knowing all the facts....Think back to the mid 60's to early 70's...Chevy underated the advertised HP ratings on alot of the high horse power car models so people could buy the Corvette or Camaro and not get reamed by the insc Co's
I had also heard stories from a few "insiders" at Bowling green that the LT-4 motors were alot stronger then what was published. :yesnod: :yesnod:
Hope this helps, Larry :steering:
I had also heard stories from a few "insiders" at Bowling green that the LT-4 motors were alot stronger then what was published. :yesnod: :yesnod:
Hope this helps, Larry :steering:
Race Director
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From: San Jose Pat Tillman - American Hero
Re: LT4 Hp Numbers (JasonL)
Ah...I see. Why in the world would anyone use a Mustang Dyno, then?
Because dynos have more purpose than just bragging rights :) They are used for tuning and diagnosis.
Because dynos have more purpose than just bragging rights :) They are used for tuning and diagnosis.
What advantage is there to using one dyno vs. the other in terms of tuning, etc., because they obviously give different #s with respect to HP/Tq?
Le Mans Master
Joined: Aug 2000
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From: Lost in the mountains of TN
Re: LT4 Hp Numbers (Perfusion)
So which dyno is more accurate?
I personally saw a LT4 with just a K&N do 307 rwhp on a Dynojet. My 91 ZR-1 when stock (only a DRM chip so I'll add 10bhp for that) did 328 rwhp on a Dynojet. At 15% loss that comes up tp 385bhp. His would be 360bhp at 15%. Now assuming the 15% is correct that would lead me to believe the Dynojet is the more accurate dyno.This is also assuming the 375bhp rating of the 91 LT5 is accurate. You be the judge.
:thumbs:
I personally saw a LT4 with just a K&N do 307 rwhp on a Dynojet. My 91 ZR-1 when stock (only a DRM chip so I'll add 10bhp for that) did 328 rwhp on a Dynojet. At 15% loss that comes up tp 385bhp. His would be 360bhp at 15%. Now assuming the 15% is correct that would lead me to believe the Dynojet is the more accurate dyno.This is also assuming the 375bhp rating of the 91 LT5 is accurate. You be the judge.
:thumbs:
Melting Slicks
Joined: Apr 2000
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From: Northern CA
Re: LT4 Hp Numbers (Perfusion)
:lol: Sorry Perfusion, I didn't mean to patronize.
I found this link on Dynojet vs. Mustang.
http://www.ls1tech.com/forums/archiv...x.php/t-132454
I found this link on Dynojet vs. Mustang.
http://www.ls1tech.com/forums/archiv...x.php/t-132454
Le Mans Master
Joined: Aug 2000
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From: Corona CA
Re: LT4 Hp Numbers (CussCuss)
Just watching the number on this board those numbers are :bs
My dynos have been pretty standards for LT4s.
299 RWHP dead stock with 55,000 miles on the car
313 RWHP with K&N and Corsas...
My dynos have been pretty standards for LT4s.
299 RWHP dead stock with 55,000 miles on the car
313 RWHP with K&N and Corsas...