I was reading the tech data on the 90 birds and it said that T tops were no longer available with the 5.7tpi.Then I looked at the 90 camaro and it didn't say anything about it.Did they also stop putting 5.7 and t tops together?Or did I miss somthing?

 

Yes they did. Now with the new safety standards of air bags, the weight of the cars with TTops didn't meet CAFE mileage requirements and would have required the "Gas Guzzler Tax". By removing the TTops on the 350 cars, the weight was down enough to not have to pay. The weight issue was also the reason GM tried using the Acrylic TTops themselves.

 

the coment was made about torque and unibody strenth.Your saying it was a political and economic resson more than stucture.How much heavyer is a ttop 350 than a hard top?I wouldnt think 10 lbs.

 

I don't know the answer to your last question. I can say that it wasn't the structural integrity of the car as many people here have added 5 speeds to their 350 cars and have had the engines built up on TTop cars and the car can handle it just fine. It was political.

 

Wieght info should be on the title.

 

T-Tops were said to be a 30 Lb. addition plus whatever the case was, maybe a pound or two.

 

What are you saying? Every car has a different weight based on the options. What did GM use to determine the build requirements? Did they take a car and load it up with all available options, weigh the car and decide that no car will be overweight because the potential is there? I don't know.

The TTops weigh 34# according to GM. They also mark the IROC-Z with the LB9/5 speed at 3319#. I show the L98 at 159# more and the Auto trans at 91#. Those are the different weights over the LB9/5 speed. So, just adding TTops, 350 and auto, you have a little over 3600#.

I don't know how GM comes up with these values because I have a fully loaded 87 with 350, TTops, Bose, leather, power everything, 4Wheel Disc, etc and the build sheet states my shipping weight at 3478#.

 

That's probably a fair guess; being a mfg engr myself at times, that's the sort of mental discipline you have to use in that field.

Since the Firebirds were generally heavier than Camaros, all else being equal, this would have been more likely to occur with them.

May also have had to do with crash testing... if it was possible for the car to exceed some specific weight value with all options, and put it into some other "class" for this purpose, that would have pretty much automatically nixed the availability as well.

May even have been something as simple as, crash testing costs BIG $$$$; and sales projections for that combo may not have met the threshold for profitability of paying for the testing.

There are alot of regulatory things like this that are near impossible to decode, this long after the fact. Emissions, CAFE, crash safety, testing and certification costs, etc. are all factors we have little visibility into out here in customer land.

 

A review in 87 listed the base weight of a 305 TPI 5-Speed IROC-Z at 3,250 Lbs. and a 350 TPI Auto IROC-Z at 3,341 Lbs. Supposedly, that is unoptioned because both cars weighed more as tested. Our cars are the same except I have no leather, Bose, or any of the trunk trim like carpet, deep well cover, or the cargo cover. It has everything else though and its' shipping weight was 3,461 Lbs. That seems correct with those few extras you have.

 

It's true that our tech data, atleast back to 2001, had stated 1990 L98 cars with T-Tops was no longer available due to structural integrity concerns. However, since information indicates otherwise, I edited that statement.

 

Was it '90 when GM tried the Lexan t-tops? I know they didn't use them very long because they cracked, but it would make sense that they tried the new material to cut down on the weight of the tops themselves.

 

the part about the wieght being on the title was a question.I should have put a ? mark not a . .Sorry.Alot of good reading here though.I was just wondering.

 

They started them sometime around 89 and used them one and off until the end of Thirdgen production.

 

I've got a guy telling me he knows of a 90 t top Iroc with a 5.7 engine thats said to be original.said it's a 50,000$ car.I didn't know that a third gen could be worth that much first off.Secondly I'd have to see it myself.

 

To prove that car is legit, you need to see the SPID label. Verify that the VIN on the label matches the car. If they match and the car has L98 and CC1, then he has a 350 with ttops. I'm doubting that he has this combination. The car is probably a 305 with factory T's or it's a 350 with aftermarket C&C tops.

 

[quote=sofakingdom;5136684]
"Since the Firebirds were generally heavier than Camaros..."

My '89 Formula 350 weighed only 3262 lbs, but that's the way I ordered it.
It had A/C, and radio, but no power windows/locks/seats, or T-tops.
They threatened that it wouldn't come w/carpet mats, but when it was finally delivered, all four were there.

 

Key word: "generally".

Some Firebirds are quite light, and Camaros are heavier than some Firebirds; but in general the Firebird product line weighs more than the Camaro one.

Well if somebody pays him $50,000 for it, it's a $50,000 car. OTOH if the asking price is $50,000 but nobody pays it, then .... it's not. Sounds like in this case though, somebody is most likely in fantasy land; got an extra 0 in there somewhere.

 

I'm with ya on that one