ZR - 1 vs LT 4

[Vettelt193]

You should be able to buy an LT4 car for 2-3k less than an early ZR1... if this is the case, add the 3k you spend on your ZR1, plus another 2-3k, and you have a supercharged LT4... figure a good 50% gain over stock, and we are talking 500-550 HP... I think that would suffice to run your ZR1 down... When adding up the numbers do it by total cost... that is car+mods.

 

[BA ZR WON]

ZR-1 vs. LT4

Well:

I agree with you in principle.. Keep this in mind though: Centrifugal superchargers(I'm guessing that's what you are talking about) generate very high *peak* numbers, not necessarily(or usually) over a broad RPM range. It's the broad RPM range an LT5 produces power that makes them so deadly from a roll...

My car produces max rwhp(384) at 5900 and carries 380 til fuel cutoff(7200). What does that mean? Each time I upshift, I'm right at the same hp level I was prior to the shift. A centrifugal supercharger doesn't have that luxury; it builds power with RPM; ie takes time to build max boost. Another thing that can't be ignored is how long is that motor going to last with 10psi(what it would take to get your quoted 550hp)? It isn't going to be as reliable as it was stock, that's for sure.

A good buddy of mine street races like it's his job. He has a wicked 540ci 91 Vette that puts out some serious rwhp; just south of 525rwhp I'd say. He's ran centrifugal sc'd Mustangs with 700rwhp and beats them. How is that possible? He produces more power over a broader RPM range.

That being said, I love the LT4, think it's a fantastic engine. Probably my favorite pushrod engine next to the original 1970 LT-1; has great torque down low and can rev to boot. I would love to have a GS convertible but I think my next one is going to be a C5; I can't ignore the improvements over the C4 platform any longer

 

[Rob]

Re: ZR-1 vs. LT4

Well:

I would love to have a GS convertible but I think my next one is going to be a C5; I can't ignore the improvements over the C4 platform any longer

:eek :eek (shock).....he swayyyyyyyyyys to the "dark side".....ROFL :L :L

 

[secondchance]

In these types of "which is better' discussions, what most seems to forget is the endurance records set by 1990 ZR-1. Significance of this is, whether its a standard LT-4, supedup LT-4 or even, here we go again, LS-6, none of these motors were proven on the track, practically flat out, for 24 hours as LT-5. Its not that tough to produce prodigious power momentarilly. However, its a different story when you push an engine at full power for 24 hrs. It will be interesting to see if Chevrolet attempts this with ZO-6.

 

[6 Shooter]

True beauty of ZR-1, for me, is the sound and a feel of a large displacement V-8 revving at 7000 rpm. I've had my share of various small block chevys. As much as I loved these motors in various cars, including corvettes, typically redlined at 5500 and worse yet, as rpm goes up, you could feel the motor gasping for air. This is true of most ohv V-8s. LT-5 was one of a few american made (Mercury Marine of all) V-8 designed to alleviate this inherent flaw of ohv engine. Design solutions led to 4-overhead cams, 32 valves and resulted in a very expensive motor to manufacture - leading to its demise. LS-6 is wonderful. However, its not as elegant a motor as LT-5.
Having owned a 91 ZR-1 for 5 years, between 91 thru 96, and driven 98,000 miles until the car was totalled (unfortunately), at least in case of the particular car, motor was trouble free and reliable as any small block chevy. Only major problem I had with that car was a burned out fuel pump.

Isn't the ZR-1 a 350 CI Small Block Motor?

 

[90 Corvette ZR-1]

Kinda sota yes. Technically its a small block Lotus.

 

[Rob]

Isn't the ZR-1 a 350 CI Small Block Motor?

349 to be exact: http://corvetteactioncenter.com/specs/c4/zr1/lt5specs.html

 

[twiget]

In these types of "which is better' discussions, what most seems to forget is the endurance records set by 1990 ZR-1. Significance of this is, whether its a standard LT-4, supedup LT-4 or even, here we go again, LS-6, none of these motors were proven on the track, practically flat out, for 24 hours as LT-5. Its not that tough to produce prodigious power momentarilly. However, its a different story when you push an engine at full power for 24 hrs. It will be interesting to see if Chevrolet attempts this with ZO-6.

The 24 hour speed endurance records set buy the '90 ZR-1 have since been re-set by a Volkswagon (or perhaps a Volkswagon owned Bugati?) with a W-16 motor. It happend not that long ago, mid 2001 I think.

The ZR-1 record was in the neighborhood of 180mph for the 24 hours. A stock Z06 could never reach this speed, as it's limited by it's gearing to the low 170's (still "Oh my GOD!!!" fast). That seems to be the only milestone set by the ZR-1 that the Z06 can not touch.

Jason

 

[ArtZR1991]

To follow up on Jason's comment.

The record is the only thing that no other car can or ever has touched. Keep in mind that the ZR1 was the only production car to hold the record, and amazing feat in itself, even if many other cars held it. Because many tried, including all of Europes big names, including mercedes. In reality, the record was established originally around WWII with a custom made car with what was in essence a fighter motor in it. That record stood untouched for 50 years until the ZR1, with a production stock engine and drive train (except for rear end and trans coolers), set the new record which it held for almost 12 years until the experimantal VW reset it. It's really quite a story, and made better by the fact that the effort was privately funded and run by a single car that was intentionally held to the minimum speed to set the record. It could actually top out at 196.

It's ok if that is the only thing other cars can't do. That's what the ZR1 was designed to do... Endurance racing in the European tradition. GM simply never followed through. Ironically, that bittersweet part of the story makes the car historically just that much more interesting. Just as the original Grand Sports of '62 were.

There are and will be many other cars that will out perform some of or even most of the feats the ZR1 can do. But the ZR1 is likely to remain unique and signifigant for a long, long time.

 

[secondchance]

Certainly even ZR-1s can be improved upon to suit a particular type of racing, whether 1/4 mile, oval or road courcse endurance run, what makes this car amazing is that it could hang with the best in all categories straight out of the dealer lot.

 

[Vettelt193]

Isn't the ZR-1 a 350 CI Small Block Motor?

The LT5 is a 350, but there were many at chevy who thought that is was a mistake to call it a 350 because people got, and still get confused... they think the LT5 is a regular small block that was modified... the LT5 of course, doesn't share anything with the standard 350.

 

[secondchance]

Only bore centerline to bore centerline dimension, evidently dictated by Chevrolet. From what I remember reading, Lotus wanted to use larger bore and reduce stroke(oversquare?) allowing higher redline.

 

[WhalePirot]

Okay, okay.

I want one! NOW!!!

 

[FrogindaBlender]

HA I just Got One!

 

[rkreigh]

the LT4 is one of the best pushrod engines and way cheaper to modify than the LT5. but you will need 40-50 HP of mods to break even with the LT5. the lt4 produces better low rpm torque, and is a very solid engine, but lacks the extended rev range and power band of the LT5. the LT5 also has extremely good durability, and with just ported intake, inj housing, headers, and a good chip, can put down close to 400 RWHP ALL DAY LONG!!! they very seldom have engine failures and make a great daily driver.

taking nothing away from the LT4, if you look at the quality of the parts and engineering in the LT5, and hear the sound of one of these babies over 7K gettin it, you won't question the complexity. DOHC is just a bit more efficient than pushrod engines from a pure engineering standpoint.

I still have my 450 HP DRM 90 ZR1 for sale at $22k (firm). car puts out 372 RWHP, and pulls hard to 7200 rpm.

yes, you could buy an LT4 powered car cheaper, but there are many zr1s in the high teen to mid 20 price range which provide excellent bang for the buck and don't need any mods at all to really haul the mail.

when modified and fitted with the 4.10 gears, the cars come alive.

my LPE 368 makes 540 crank hp, idles like a kitten, and pulls hard to 7500. expensive??? sure it was, but it does everthing well and the look, sound, and performance of the ZR1 is worth the price of admission.

before you dismiss the Z, drive one, they are an amazing car.

having said that, I'm going to also buy an LT1 automatic for my wife to crooze in and put together an LT4 stroker motor someday to have a slushbox toy.

all the vettes are great cars, enjoy them!!!

 

[secondchance]

Totally agree Ron.

 

[6 Shooter]

Can a person ever . . .

. . have too many Vette's?

 

[ArtZR1991]

no.

 

[YESZREE]

Isn't the ZR-1 a 350 CI Small Block Motor?

Yes it is a small block but...like none you've ever witnessed.

I have a 91 ZR-1 with ram air,a Doug Rippie chip some upper porting and headers/Borla Exhaust. I can tell you that was less than 2k in mods and when I shift to 4th I'm over 150mph. I have never run all the way through 4th at full power but I would estimate that that would be the area where an LT-4 would be flattening out and I'm still pulling like a mad man.

Like others have said, there are many Corvettes out there since 50 years of production but let me tell you that there is NO OTHER like the LT-5 and there never will be. The statement concerning the full power band in all gears at all speeds is a benefit of overhead cam technology.

Why do you think Ford has the Mod Motor. What do you think runs at Indy? These engines are heads and shoulders above pushrod motors for speed and endurance.

Now, lets stop all this nonsence and be friends!

But the ZR is King!

 

[Rob]

:L Ed,

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