GN too heavy...any ideas?

[unix_punk]

So, I've had some trouble lately breaking into the low 13's on the setup in my sig... After being frustrated and looking for a somewhat reasonable reason why, I decided to weigh the car...3920 with me in it?! I weigh 235! Every other T/GN owner I've talked to says theirs weighs about 3650-3700 with them in it...These cars were all full weight cars just as mine is. Car has an ASC power sunroof if that makes much of a difference, I figure 80 lbs at most.

Anyone have any ideas?

Thanks in advance.

 

[t3intercooled]

People basically say that each 100lbs shed off is a 10th in the quarter. Not sure what your 60 foot times are but each 10 shed off in the 60 foot time is around 2 tenths in the quarter, so a good set of slicks or drag radials will help you accomplish that. Now you can go with all aluminum pully's from RJC racing, the set is 419.00 and will drop between 9.5-10lbs of rotating weight which in turn is the same as 95-100lbs of non rotating weight. Can go with a fiberglass front bumper, aluminum wheels, fiberglass hood, tubular suspension. There are various things you can go with to help shed weight. If you go with a hollow f body front sway bar, its larger and lighter, the best of both worlds. If you have the stock radiator you can go with an f body radiator which is a 1 huge row aluminum radiator. Its lighter and the one huge row in my opinion is better than multiple smaller rows also check out this link, it may help you as well:
Weight savings: I hope this helps.

 

[unix_punk]

Those are all good suggestions, I was just hoping someone had some insight as to why my factory weight car weighs 250lbs more than every other factory weight car I've seen...

As far as 60 foot times, strange beast there. on 28" et streets (stock rims) I could cut 1.80's consitant, on a barrowed set of 26" et street radials (on draglites) I could not do better than 2.04... doesn't make sense to me... the only difference I thought of is the 28"s seemed to let me hold closer 10psi on the line where the 26"s would only hold around 5psi.

 

[t3intercooled]

sunroof cars do add more weight, how much more do you weigh than your friends? Also what turbo are you running. Try buying a set of straight slicks, should bring you down near 1.60 60 foot times, which should drop your 1/4 mile ET by 4 tenths which is huge. Plain regals are also a little lighter than GNs

 

[fitz3820]

The great thing about this car is that it is easier/cheaper to make power than reduce weight.

I don't know about you but I would not drive on the street with fiberglass bumpers or anything else that would make the car less safe in a wreck.

How much boost are you running?, what are your WB/scantool numbers?

 

[unix_punk]

Ive compared mine to 2 full weight hard top 87 gn's, both had the hr parts rear sway bar I only weigh about 20lbs more then the other guy(s). Stock turbo.

No one else has an 87 GN that weighs 3700 WITHOUT them in it?

 

[unix_punk]

Boost get 21-22, I run the WB no higher than 11.5. But it's not consistant, the VE is off a bit so it falls rich as RPMs go up. Timing is almost 27/25. Slight knock here and there, no higher than 2.0, usually in 3rd. Best pass was 13.4@102. Dont remember if the 2.04 60' was from that run or not.

 

[ChrisCairns]

Where did you get it weighed? Perhaps the scale was wrong.

I once had mine weighed at a farm store. I asked the attendant how accurate the scales were and he said when they used to buy grain from farmers it was very accurate. He went on to say they've stopped buying grain so the scale was probably minus/plus 100 lbs.

Which told me it wasn't accurate and he was just guessing at it's accuracy.

The BEST place is a government weigh station and if you can find them at a non busy time they'll probably do it for free.

 

[SPOOLN]

My car weighs 3879 with me in it. You just need more HP. Try a lower timing chip like 18-20*. That alky makes your intake charge more efficient so you wouldn't need that high of timing. Hope this helps.

 

[fitz3820]

Boost get 21-22, I run the WB no higher than 11.5. But it's not consistant, the VE is off a bit so it falls rich as RPMs go up. Timing is almost 27/25. Slight knock here and there, no higher than 2.0, usually in 3rd. Best pass was 13.4@102. Dont remember if the 2.04 60' was from that run or not.

Hmmm, with that much boost you should have way more MPH than that - something is fishy - that is pretty close to stock mph which is ~99-100 mph. Valvesprings maybe?

 

[unix_punk]

Car was weighed at Byron, IL Dragway. We weighed mine and then weighed another 87 GN... Same scale...

Correct me if I'm wrong (Julio) but isn't the purpose of running methanol to allow you to run more boost...but when you cant run more boost it allows you to run more timing... More timing=more power in almost every situation i've seen... 20/18 is 93 street timing without methanol... methanol timing is usually 23/21, 24/21 or so. Valvesprings may be stock, I have a set going in this winter.

 

[notacarlo]

I'm gonna jump in.

Is the car being weighed with a full tank of fuel? Is the spare still in the trunk?

If this has already been answered, ignore me.

 

[unix_punk]

Hasn't been answered but has been taken into account. At 7lbs/gallon, I figure around 28-35lbs was from the difference in our fuel tanks. We both had spares and factory jacks in the trunk.

 

[Quint]

My car when I got it was 3600+ with out me in it and 3850 + in it, so the car is right now with most GN's. I had Ttops, so it was a bit heavier. Dont worry about it, just add more HP and you willl be ok.

 

[DavzGN]

What about stereo equipment? lots of extra weight can be added with an upgraded stereo. Also the power sunroof does add a lot of weight over a hardtop, but I doubt it is that much.


HTH
David

 

[Quint]

Ive compared mine to 2 full weight hard top 87 gn's, both had the hr parts rear sway bar I only weigh about 20lbs more then the other guy(s). Stock turbo.

No one else has an 87 GN that weighs 3700 WITHOUT them in it?

Dont worry about it, I promise you there are other stock GN's that can tip the scale at 3700 with gas. To me if the car is heavier its got more of the goodies in it somewhere on or in the car stock:smile:

 

[t3intercooled]

Well there is probably an issue engine wise then, casue I agree you should have a much larger MPH. And math is exactly that math. Try and weigh the car with only 1 or 2 gallons of fuel, no more, take your jack and tire out, and try ther government weigh station.

 

[unix_punk]

Well, my personal goal is to get 12's on a mostly stock setup (inj, and turbo) which should not be difficult to do... Thats the reason I ask, as I do have a TE60 sitting waiting to be installed after the trans and stall are installed. But from what i've heard and read, 12's is not an unreasonable goal on stock turbo and injectors.

Stereo is a fosgate head unit with 6x9's in the rear deck, nothing more...Car was upgraded (by previous owner) to Concert Sound (or whatever you wanna call 2 extra speakers and crossover units...)

 

[John Larkin]

You can pull an easy 100lbs out by changing the front and rear bumper reinforcements to aluminum + pull that tar paper sound deadener from behind the rear seat. Replace it with a nice black piece of fabric from craft store. Removing front sway bar will remove 20 more and allow your car to weight transfer better on launch which will reduce your 60'. I wouldn't take off much more on a street car. 100 lbs = 0.10 extra ET + probably 0.20 better 60' = you're in the 12s.

 

[mikestertwo]

My son's car is a 87' GN astro roof car and it weighed 3650# with 1/2 tank of gas in factory stock form, no driver. Put aluminum bumper backings in, front and rear, changed the GN rims to T-type rims, F-body radiator, removed spare tire and jack, removed front sway bar, installed aluminum rear brake drums. Now the car weighs 3450#