LT4 The C5 LS1 outran the C4 LT4 in every way ...

[tlong]

I took my friend's word on the difference. It will soon be confirmed or corrected by my esteemed CAC brethren.

 

[DRTH VTR]

I took my friend's word on the difference. It will soon be confirmed or corrected by my esteemed CAC brethren.

They ARE different, but I cannot quote the firing order off the top of my head.

 

[Vettelt193]

1-8-4-3-6-5-7-2 = Gen I and Gen II


1-8-7-2-6-5-4-3 = Gen III

The cylinders are still paired the same, the pairs are moved though. I've noticed no difference in smoothness between Gen II and Gen III though

 

[code5coupe]

By the way, this is not a poke at the LS1 which is a great engine with many advances, just a comment on the print media's apparent lack of awareness when it comes to the LT4 sometimes.

It may be a lack of willingness to put something in print that they cannot substantiate. The automobile media will occasionally print something that is an "urban legend", but they will almost always identify it as such.

Larry

 

[Roadster Guy]

It may be a lack of willingness to put something in print that they cannot substantiate. The automobile media will occasionally print something that is an "urban legend", but they will almost always identify it as such.

Larry

Ah, but Larry they did put something in print they could not substantiate as this thread heading stated: "the LS1 outran the LT4 in every way....".

RG

 

[lt4 gs]

ummmmmmmm! bring it on home to papa...

 

[LT4-FUN]

Agreed. BUT. 4 out of five 5 LT5s that I have "raced" I have beaten. All have been stock. Not by much, mind you and under primitive conditions. {ie}
Street. Stop light 1/4 miles etc. I'm still wondering about that one that got away. Hmmmm

 

[6 Shooter]

4 out of five 5 LT5s that I have "raced" I have beaten.

Thanks for the humor, a laugh is always good! :L

Later . . . . . .
6 Shooter

 

[simbadb]

LT4 ... This engine will prove collectible over the years ....

<< From The 1996 GS Registry: A Very Well Done Piece On The LT4 vs. LT1
http://www.grandsportregistry.com/lt1vslt4.htm >>

It is nice to see that apparently most LT4 owners are very pleased with and enjoy the performance of this engine. You hear positives about the low to mid range torque quite frequently and that it is a sweet and fun engine.

I would agree that engine progression from the C4 through the C5 and C6 has been steady and measured and that the configuration and structural improvements that arrived with the C5 were a large leap over the C4. That being said the C4 was equally a huge advance over the C3 in many areas.

Maybe because the LT4 was a one off engine for 96 it will remain a little special and perhaps add slightly more value than say a LS1 would in the long run. The LS1 is more advanced than the LT4, but there are almost 200,000 out there and only about 5000 of the LT4's (from memory, don't have my black book with me) kicking around. In the older Vettes when there were different engines around some of the more desirable ones definately add extra value now ( LT1, 427, 327 fuel injected etc.) Ah, but all that is for another thread though isn't it........sorry guys, got meandering....
RG[/quote]

 

[trebor]

I can say having gone from an LS6 (2002 Z06) with 4138 miles on it when I sold it to a '96 LT4 CE Z51 with 13000 miles on it, the LT4 is not a disappointment. I wondered if it would feel too slow but having driven the LS6 for 2 years and knowing what it was capable of I can say I look forward every time I get a chance to drive the LT4. The LT4 has to be under rated because it has a nice smooth low range acceleration and even at highway speeds I can drop it into 4th and drop the hammer and feel it kick. The LS1 is a great motor but I am convinced my LT4 will not only keep pace with it but out accelerate it. For those wondering I sold the Z because I did not race it (on the track) and it was more car for the street than I needed. You can check out my Z and current LT4 here:

http://www.angelfire.com/hi/nicecorvette


Trebor

 

[6 Shooter]

The LS1 is a great motor but I am convinced my LT4 will not only keep pace with it but out accelerate it.

Keep telling yourself that and pretty soon you will start believing it! ​

L8TR - D

 

[simbadb]

Indeed, the LT4 is seriously under graded on the spec sheet at 330HP. Per this site (dont recall where) a tuner from GA has run over 100 LT4's on his Dyno. If I recall, a fair number of these come in in excess of 370HP. A friend of mine who knows a considerable amount about cars and drives many, took my LT4 out this past week and was simply amazed. I have done some minor mods that contributed to the performance (SLP Cool Air Intake, Flowmaster mufflers, Hypertech Tune). I expect to get mine on the Dyno over the next week or so and will report where she comes in.

I can say having gone from an LS6 (2002 Z06) with 4138 miles on it when I sold it to a '96 LT4 CE Z51 with 13000 miles on it, the LT4 is not a disappointment. I wondered if it would feel too slow but having driven the LS6 for 2 years and knowing what it was capable of I can say I look forward every time I get a chance to drive the LT4. The LT4 has to be under rated because it has a nice smooth low range acceleration and even at highway speeds I can drop it into 4th and drop the hammer and feel it kick. The LS1 is a great motor but I am convinced my LT4 will not only keep pace with it but out accelerate it. For those wondering I sold the Z because I did not race it (on the track) and it was more car for the street than I needed. You can check out my Z and current LT4 here:

http://www.angelfire.com/hi/nicecorvette


Trebor

 

[Hib Halverson]

Keep telling yourself that and pretty soon you will start believing it! ​

L8TR - D

You may be convinced of that but, I'm sorry to say you've been drinking too much luddite coolaid.

First, let me say that I drove both back then. A 96 GS Coupe and a 97 Coupe both for, I believe it was, Corvette Fever magazine.

Here are the facts.
GM did give the LT4 a very conservative power rating. I'll surmise it was 10-15hp less than the average output of the entire LT4 production. I doubt the vast majority of LT4s made 25 more SAE Net hp.

"Corvette Magazine" is correct in saying the LS1 outran the LT4 in every category. It may not have outrun the LT4 by much in the power department, but in the real benchmarks engineers use, such as torque curve, specific output and/or power density, it had a more useful torque curve, it did outrun the LT4 by a bit in output and by a significant amount in density.

The discussion, here, has focused more in engines than on the whole vehicle.

The 96 manual coupe weighed about 100 lbs more than a 97 manual coupe and the difference may even be greater depending on how two specific cars being compared are equipped. That is, if you took a loaded 96 GS coupe and compared it to a base C5 manual, the difference might be 150 or even 200 lbs.

The 97 has a slightly better weight bias than a 96, ie, a little bit more weight on the rear wheels.

If you put all these facts together, it's pretty unlikely that the majority of 96 manual coupes which are stock are going to be quicker than the majority of 97 coupes which are stock, *even if* all the 96es have 345 hp rather than 330.

Now, given the equal driving skills and both cars operating properly, can an "average" 96 manual Coupe which is stock run close to a 97 manual Coupe which is also stock?

Sure.

Will it be noticeably quicker than the 97.

Not even.

 

[simbadb]

Look Under LT4 Performance Review ...

The performance figures and specifications listed below were compiled by Forum Member, Stan A (Stan Adelman) of Auto Performance Test Lab located in Atlanta, Georgia. The Corvette Action Center would like to thank Stan for allowing us to post his Performance Review Data here.
Regarding the stock LT4 horsepower numbers, Stan explains:

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.
​

http://corvetteactioncenter.com/specs/c4/1996/96perf.html

 

[jonecap]

When I bought my '96 LT4, it had a set of 4.10 gears and a Magnaflow catback. Other than that it was stock. On drag radials in 80 degree air, it ran a 12.60 at 112mph. I then added a Meziere electric water pump and had it tuned. It then ran a 12.19 @ 114mph. I added long tube headers and it ran a 12.05 at 115.06mph...all with bolt-ons.

I have yet to see a bolt on C5 or C6 at the track running faster times...or a ZR1. I'm sure they're out there, but I haven't seen them. LT4 cars have a ton of potential.

Here's a video from the National Corvette Challenge after I put the headers on [url=http://videos.streetfire.net/video/afdff011-ff85-4378-9761-98e000e12a7c.htm]'96 LT4 12.14 pass at National Corvette Challenge[/URL]it:

 

[Hib Halverson]

Both the previous posts do little to prove the premise that stock 96 Corvettes with the LT4/manual powertrain accelerat quicker than stock 97s with LS1/manual powertrains.

simbadb's post, citing Mr. Adelman's testing, discusses engine performance not vehicle performance. As an aside, I should add the data offers no insight as to whether the flywheel power figures are SAE Net, or not, or are derived from rear wheel torque output or measured with an engine dyno.

jonecap's post quotes some impressive numbers but--I complement jonecap for this--admits the car has an aftermarket exhaust, 4.10 gears and drag radials. Those three mods, on a 96 are probably worth 0.7-1.0 seconds off the e.t.

Clearly, that car is a potent machine, but it's performance is not credible evidence to support the point made at the start of the thread.

 

[code5coupe]

The performance figures and specifications listed below were compiled by Forum Member, Stan A (Stan Adelman) of Auto Performance Test Lab located in Atlanta, Georgia. The Corvette Action Center would like to thank Stan for allowing us to post his Performance Review Data here.

Regarding the stock LT4 horsepower numbers, Stan explains:

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.​

​

I recall seeing this quote several years ago on the CF. I have the same comments today that I did then:

Since few tuners use an engine dyno instead of a chassis dyno, their hp/torque values are estimates, based on an arbitrary conversion factor (for rear wheel torque/hp to flywheel torque/hp). This means that the 345/360/375/392 figures are based on someone's guess as to drivetrain power losses on a chassis dyno.

Second, chassis dynos are notoriously unreliable/inconsistent as to power values....and using the figures given by one Dynojet over several years is asking for problems.

Third, knowing how the factories build engines and arrive at published power figures, (my personal opinion is that) it is impossible to produce "rogue" engines that put out over 60 horsepower (+18%) more than the low figure in the range (330).

Ask yourself what changes would have to be made in the engine to produce even 15 more hp and you'll quickly come to the conclusion that it won't be done "by accident", on the assembly line.

I, personally, still have seen no proof that stock LT4's produce more than 330-335hp (normal variation). That's the bottom line.

Larry
code5coupe

__________
not easily impressed....

 

[july349]

I own a 96 LT4 Vette and when I bought it ( used in 2001) I researched the LT4 engine at ( then LT-4.com ) and in doing so I found out from the guy that had dyno tested hundreds of LT-4s that bone stock no LT-4 ever came in at less than 345HP but did go as high as 390HP bone stock from the factory. I also read in a Corvette magazine a few years ago that the LT-4 would run with and sometimes out run LS-1s all day long. I tend to believe the man who tested these engines performance for a living.

 

[Vis Croceus]

I own a 96 LT4 Vette and when I bought it ( used in 2001) I researched the LT4 engine at ( then LT-4.com ) and in doing so I found out from the guy that had dyno tested hundreds of LT-4s that bone stock no LT-4 ever came in at less than 345HP but did go as high as 390HP bone stock from the factory. I also read in a Corvette magazine a few years ago that the LT-4 would run with and sometimes out run LS-1s all day long. I tend to believe the man who tested these engines performance for a living.

Thanks for bringing back this dead thread just to repeat the same erroneous info that was already here.

 

[Roadster Guy]

Thanks for bringing back this dead thread just to repeat the same erroneous info that was already here.

Oh, that was a bit harsh. Do I detect a little LT4 jealousy?
RG