Some questions about the different years

[MuRCieLaGo]

Hi,

I got some questions.

1. At what year was introduced the convertible ZR-1?

2. I saw the engine had a boost in 1993 of like 20hp. Is it internal or external upgrade? I mean, could I buy a 1992 and easily get these mods?

3. What are these exterior restylings it had over the years?

Thank you!

[Z06scentair]

Hi,

I got some questions.

[COLOR="SandyBrown"]
1. At what year was introduced the convertible ZR-1?

Never introduced to the public .

2. I saw the engine had a boost in 1993 of like 20hp. Is it internal or external upgrade? I mean, could I buy a 1992 and easily get these mods?

Yes 375 to 405. Lots of motor revisions. Different block 2 bolt later went to four bolt. Injector housings, cam timing....lots of things really. Can you make a 375hp motor make 405hp...Yes.

3. What are these exterior restylings it had over the years?

91 changed the front fascia, and wheels from 90.

No change in 92.

93 changed to a machined faced wheel plus 40th anniversary Ruby Red was an option Z25, HP increased to 405.

94 seats changed as well as dash and console, A mold wheels were standard.

95 last year later cars had dunn heads. Dunn was the replacement supplier for Birmall who went through bankruptcy. Dunn heads flowed better which resulted in a little more power according to testing. Only exterior change was the side panels in front of the door.

Thank you!


See above.

[MuRCieLaGo]

See above.

1. Ok, I found a ZR-1 convertible in the local ads, that probably means it is not a real ZR-1...
2. I know I can easily mod the motor to have it make 405hp. As you said, it is a different block so I can't mod a 1992 motor to become a stock 1993 motor with 405 hp... Am I right?
3. What do you mean by a little more power?

Thanks for your patience and your clear answers!

[edram454]

it takes very little to make a 1990 motor make 405 hp. the 1990 picks up more horsepower from plenum and injector housing porting because of the smaller ports from the factory. The 1990 has a two bolt main block. Do you need a 4 bolt?? no. remember.. the record breaking car that averaged over 175mph for 24 hours straight had a two bolt block. If you need more than that then you need a full blown race car. If you retime the cams you can pick up some more plus adding headers and tuning. Dont shy away from the 1990. They run every bit as hard as the later ones.

ed ramos #3028

[phrogs]

well there are a few ZR-1 convertible conversions out there but I doubt its real.

[MuRCieLaGo]

Thanks for your simple answers!

I'll make it even easier:

Which engine is the BEST? 1990-1992 or 1993-1995?

[XfireZ51]

Thanks for your simple answers!

I'll make it even easier:

Which engine is the BEST? 1990-1992 or 1993-1995?

Supposedly the last 95 motor because of it being a 405hp WITH DUNN heads.
However, the 90 is lighter than the 95 so IMO, # per HP may be the way to look at it. As has been said, 90-92 motors are very responsive to basic mods to level the playing field.

[cvette98pacecar]

Thanks for your simple answers!

I'll make it even easier:

Which engine is the BEST? 1990-1992 or 1993-1995?

90-95 is the best engine. There is no difference in strength from the two bolt to the four bolt block.
I do believe Frank's and Al's 441 are both two bolt blocks.

[Paul Workman]

Agree w/ all said so far.

Here's a link to Marc Haibeck's site (http://zr1specialist.com/HAT%20Web/products/major%20engine%20upgrades.htm).

Mark performs performance upgrades to the LT5. You'll see there that where the 90-92 375 hp motors and the 93-95 motors receive the full treatment, their respective performance is equal.

One thing many don't realize too is the head bolts on the LT5 are MASSIVE, compared to a typical SBC. (edit) And, the main bolts of the two-bolt block are also massive, whereas the the bolts in the 93-95 mains are 4/main, the size of the bolts are smaller.

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/LT5block4_zpsebca3327.jpg (http://s185.photobucket.com/user/6PPC_bucket/media/tech%20files/LT5block4_zpsebca3327.jpg.html)
90-92 block

...and examples exist of 415, 427, and 441 cid displacements with 2-bolt blocks that are straddling 700 hp, NA on pump gas. Try that with a SBC!

Aside from sharing bore center dimensions, there are no interchangeable parts with the SBC, and certainly no comparison either with the LT5's rugged "bullet proof" reliability or output per cubic inch for a street driven motor.

So, I wouldn't give 2 vs. 4 bolt LT5s a second thought, especially if it is to be fully ported anyway. And, offsetting the 30 hp advantage of the 93-95 ZR-1s, is the additional weight.

Performance wise, it is pretty much a toss-up across the years in stock form.

[BigJohn]

Thanks for your simple answers!

I'll make it even easier:

Which engine is the BEST? 1990-1992 or 1993-1995?


Mine!!!!


:neutral:

[MuRCieLaGo]

Agree w/ all said so far.

Here's a link to Marc Haibeck's site (http://zr1specialist.com/HAT%20Web/products/major%20engine%20upgrades.htm).

Mark performs performance upgrades to the LT5. You'll see there that where the 90-92 375 hp motors and the 93-95 motors receive the full treatment, their respective performance is equal.

One thing many don't realize too is the head bolts on the LT5 are MASSIVE, compared to a typical SBC. And, the head bolts of the 90-92 two-bolt block are larger than the individual bolts of the 4-bolt 93-95 block. And, many examples exist of 415, 427, and 441 cid displacements with 2-bolt blocks that are straddling 700 hp, NA on pump gas. Try that with a SBC!

Aside from sharing bore center dimensions, there are no interchangeable parts with the SBC, and certainly no comparison either with the LT5's rugged "bullet proof" reliability or output per cubic inch for a street driven motor.

So, I wouldn't give 2 vs. 4 bolt LT5s a second thought, especially if it is to be fully ported anyway. And, offsetting the 30 hp advantage of the 93-95 ZR-1s, is the additional weight.

Performance wise, it is pretty much a toss-up across the years in stock form.


Thanks a lot guys and thanks for your detailed answer Paul.

Would it cost much to have a '90 motor modded the exact same way that gives the '93 motor these 30 extra horsepowers? Is it doable?

Again, thanks for your patience and I really appreciate it!

[efnfast]

I'm about 5 grand into mods on my 90. Headers, exhaust, ported plenum and IH, chip. Just dyno'd at 397 rwhp, that's 465 at the crank. Can't believe I've added 100 hp the car since I bought it. 50+ to go. That'll be heads and cams. -Steve

[edram454]

Thanks for your simple answers!

I'll make it even easier:

Which engine is the BEST? 1990-1992 or 1993-1995?

whatever your best deal is. they made more 1990 zr1 than any other year. they are the better deal thus the better buy. My two cents.

ed ramos #3028

[rmendoza]

What is the benefit of just adding the Haibeck chip?

Can a layperson do it or does it require a knowledgeable mechanic?

[ZRXMAX]

What is the benefit of just adding the Haibeck chip?

Can a layperson do it or does it require a knowledgeable mechanic?

Marc H does custom recalibrations depending on how your car is set up.

Headers, gears, porting,etc all have an optimum tuning challenge. Marc will get your car pretty close depending on what your car has.

As far as changing the chip... its easy. You do need to pay attention and be careful with the pins when reinstalling the chip. Not hard to do at all.

[RyanChappel]

also in '91, the ZR's went away from the contrasting side moldings/door guards, and went to finishing them with the same color as the car...if a car has the contrasting molding, it is the original year manufacture...IIRC!

It is the main reason I went with the '91


#1929

[Fully Vetted]

Thanks for your simple answers!

I'll make it even easier:

Which engine is the BEST? 1990-1992 or 1993-1995?

What everyone is saying here (and some of us have the early cars, some the later cars and some BOTH) is basically don't pick your car based on which engine you think is best from the stand point of the early version or the late version. Look at it as across the board all the engines were the same and then start finding the best car you can afford. Can't get any simpler than that.

[edram454]

What everyone is saying here (and some of us have the early cars, some the later cars and some BOTH) is basically don't pick your car based on which engine you think is best from the stand point of the early version or the late version. Look at it as across the board all the engines were the same and then start finding the best car you can afford. Can't get any simpler than that.

You are absolutely correct Sir!!

[Paul Workman]

Thanks a lot guys and thanks for your detailed answer Paul.

Would it cost much to have a '90 motor modded the exact same way that gives the '93 motor these 30 extra horsepowers? Is it doable?

Again, thanks for your patience and I really appreciate it!

Why stop there (at 30 hp gain)? Adding 40-50 hp or more to the rear wheels of a 90-92 is doable with top-end porting and port matching: not too difficult as a DIY winter project!

The thing is, the LT5 in its factory trim is starving for air! This means there is a great deal of "low hanging fruit" available with simple plenum and injector housing porting. Full head porting will add another 20-30 to the wheels in conjunction with a dyno tuning session by a skilled LT5 tuner. (Mine is but one example; making over 430 hp at the rear wheels on stock cams and un-ported throttle body. (see my signature))

http://i185.photobucket.com/albums/x220/6PPC_bucket/Dyno%20graphs/DynoLT510-19-10.jpg (http://s185.photobucket.com/user/6PPC_bucket/media/Dyno%20graphs/DynoLT510-19-10.jpg.html)

This is one of the beauties of the DOHC motors: they will breathe (if when not choked) and make power way up the rpm band too!

And, the LT5 was built to endure. On the engine stand at Lotus, the LT5 test motor was run continuously for over a week, alternating between max rpm (7000+) and peak torque before being torn down and checked for wear. According to accounts, the motor was still in spec and could be reassembled and run some more.

If you really want to understand what the ZR-1 is and understand what the LT5 really is, you need to read "Heart of the Beast" (http://www.amazon.com/Heart-Beast-Anthony-Young/dp/0971146845/ref=sr_1_2?s=books&ie=UTF8&qid=1407593771&sr=1-2&keywords=Heart+of+the+Beast)by Anthony Young ("required reading" for ZR-1 owners!)

[MuRCieLaGo]

Again I want to say thanks to all of you who keep answering my questions.

I just don't way to say in 5 years "I should have bought a '93-'95.

I don't want to have ANY disadvantage with a '90, compared to a '93, ONCE MODDED.

1st example:

I own a '93 RX-7. Engine had slight mods in '99, but that was really easy to get. So I don't have any disadvantage when compared to a '99.

2nd example:

Toyota Supras have different engines. 2JZ-GE and 2JZ-GTE. You just CANNOT expect the 2JZ-GE to be equal to a 2JZ-GTE.


That being said, do you compare the ZR-1 situation to a RX-7? I know, my question might be strange, but it is really important for me. I don't want to regret my choice (I did not regret my choice for my RX-7 that I own since 2007).

[Z06scentair]

Can't answer your question to regards of comparing to the foreigns you mention.

What I can say is as far as performance....it's really dead even for safe sake. Stock for Stock

The major difference is feel in the cockpit due to the seat changes from 90-93 to 94-95. It's going to come down to your feel in the piloting seat.

I for one love the earlier seats once your in them. Getting in can be a difficult task depending on the size of the fellow. The later seats are much easier to get in but not as much upper body support.

This is all based on my opinion and having owned many C4 cars over the years.

The best thing for you to do is decipher price range and start searching! We/I will not be held responsible for ticketing that may occcur from excessive usage of the secondaries!

[Paul Workman]

I cannot relate to the RX analogy, but if you refer to Marc's web site, you'll see
that with the "full Montie", both motors 90-92/93-95 are equal.

[edram454]

a 1990, if it has had a plenum and injector housing port job, long tube headers and the usual mods that alot of them have, will not give up anything to a 93-95. The 93-95 are usually more money unless you get a car with some mileage. There are plenty of 1990 and 1991 that flat out fly and the 93-95 have nothing on them. the extra horsepower of the 93-95 came from tuning and a little better intake flow from the factory and maybe a little bit of cam timing etc.. not much at all. A 1990 and 1991 with an intake port more than makes up for that hp difference and you can bet a much better deal because they simply made more of them. I would have never bought my 1990 if I thought for a minute my engine was inferior in any way to the other lt5. You most important task is to find a good car and hopefully with some good mods, not trashed and ready to go. If you can get one with intake plenum and injector housing port along with head porting then you got a winner. there has been one for sale in this forum for some time in arizona.

[johnboy89]

For a noob I found this thread very informative!!! :)