Raistlin

Went up to Jacksonville, NC Thurs. to see how the corvette would run. I got three runs in and the last was the best. Had under a 1/2 tank of fuel w/octane boost (I think I might be pinging). I've had the car for a year, and don't know anything about it's history, other that it came w/the original window sticker :) . Here's my best run of the night. Comments are welcome.
1.29 --- Reaction
2.00 --- 60ft
8.79 --- 1/8 et
79.51 --- 1/8 mph
13.67 --- 1/4 et
99.52 --- 1/4 mph

My question is for other zf6 l98's. I was topping out 4th gear at the end of the quarter. I was spinning 5500+ rpm @ ~101mph. Is this where you guys are at? It seemed strange to me to be running out of 4th gear. I had my eyes on the tach and I almost instinctivley shifted into 5th, till I figured I could make it to the end in 4th.

Kale

wow, your reaction time is horrible! Go on the last yellow light LOL!

Mid 13!? The car MUST be modified, or you've set a new stock l98 record!!

scorp508

Something has been done to that car. :)

Also, I think you're holding out 4th gear waaaay too long. You should be shifting around 4500. :) But hell with those times, don't listen to me!!! :D

4th gear is also the 1:1 gear in the ZF6, ringing it out to 5500 should have you well over 100mph. That rear end may be changed. Jack up the rear end of the car so both wheels are off the ground, put the car in neutral, and spin the tires. Coun't how many full revolutions the driveshaft makes in ONE complete turn of the wheels. :)

J Z06

Impressive. My take is, it has been tweaked a little.

Nice job.

Raistlin

Hey Smash,

I think I'll edit my first post.

Comments are welcome, but please don't pick on my reaction time. It was late and I needed a little nap. :D

Beach Bum

Good run...:)

Are you sure you're at 5500 rpm ??

Assuming a 26.4" tire with a Loaded diameter of 25.2".....

In 4th gear with 3.45's @ 100 mph = roughly 4600 rpm
In 4th gear with 3.73's @ 100 mph = roughly 5000 rpm
In 4th gear with 4.11's @ 100 mph = roughly 5500 rpm

I think you would have know if you had 4.11's. (Which incidently per the simulator slowed you down 2 tenths vs the 3.73's, probably because I held you in 4th which really overrevs you with a basically stock L98 rpm band)

good luck
Beach Bum

Raistlin

Hey Scorp,

I agree on holding out 4th, I was shifting all other gears @ ~5k. I could here it breaking up at 5500, but I was right at the speed lines, the last 60ft?

I didn't want to jack the car up w/out hearing what you guys said, but now with your feedback, I'll let you know what I find out.

Nomar116

Yea the numbers are printed on the rear end... Also look under your arm rest compartment, and on the underside of the lid are some codes... Youll see One of the following somewhere on there....
GH0
GM1
GM3
GT7
GU2
G44

Let us know what the rear end reads, and what thet lid reads, if that code (matching it with my manual) is the same as your numbers on the rear end its stock.... Ill bet that car isnt actually at 5.5k.... My 90s tach is off by more than a grand that high... Ive tried to fix it with no luck, what does the dash say your idleing at?
paul

scorp508

The last 43ft I think if we want to split hairs. :D

It really shouldn't break up that high, it should just run outta steam at 4800 and make more noise at anything higher. If you can, also check the base timing out and see what it is set at. 6 degrees BTDC is stock, and I've been told 8 to 8.5 is optimal.

My car was breaking up badly over 3900 and it turned out to be because my timing was waaay off because of a failing distributor gear.

AS84

the tach on my 90 is way off also. Idles at 1400 but my diagnositcs scanner says its at 750 rpms. I have been told to disconnect the tach filter, but I haven't found it yet.

The code on my rpo list is GT7. What ratio is that?
thanks

Nomar116

I hate when people get the luck of the draw .... :( :mad :mad Nonetheless.... Scorp your a lucky guy... Similar mods for the two of us yet you have the.... :sad: 3.45 gears to my 2.73.... Congrats on the good news maybe I just saved you from spending a few hundred down the road huh? :cool:
Oh and as for tach filter... Dont bother, did me no good at all, plus now I dont have the filter... not that that really matters I have a little aftermarket gage in the upper left corner of the dash



[Modified by Nomar116, 1:23 PM 10/13/2001]

Kale

My first R/T was 1.19 :D

Raistlin

Thanks for the comments guys,

I have the GT7 code on the lid, and the driveshaft spun 3.5 times for one revolution of the wheel.

It has the stock computer chip. I just checked

The last time I set the timing, a couple of months ago, I set it to ~7btdc, if I recall correctly.

The only changes I made to the car was a major tuneup, in which I replaced the cap, coil, wires (all three summit performance), ignition module (accell) and plugs (don't remember what brand).

My idle reads 1k rpm, but I messed with the base idle setting which still had the metal cap on it, when I was trying to find a problem. My g-tech would show a 16sec 1/4, then I'd get a mid 14, the car was not consistant at all.
Anyway, I think the idle speed is correct, but the tach has been sticking lately.

With a speed of 99mph, I don't think I'm makeing more hp than stock, and I am at sea level.

What rpm should I be at at 100 in 4th? Anybody know?

Edited by Raistlin
Nevermind, I see it should be 4500rpm for 3.45's. I guess my tach is way off and I was actually shifting at a little over 4k. Guess it's time for an accurate tach.


[Modified by Raistlin, 2:17 PM 10/13/2001]

Ezgoin721

Thats a mighty fine time and speed for a stock 90. :cheers:

Nomar116

Ill tell ya right now thats a VERY impressive time. Although Im sure those 3.45 gears help alot... Thats your answer there I figured as much, inaccurate tach as well as an AWESOME rear differential (compared to my 2.73's :sad: )
BTW DOUBLE CHECK that rpm.. You'd hate to find out the tachs accurate when you run it up an extra 1k rpms ... Buy a cheapo tach something small I found mine at Advanced Auto Parts for $15 its only like 2 in big or something So it doesnt stand out at all... But looks good for a sleeping "hot rod"
Paul :crazy: :smash:


[Modified by Nomar116, 3:07 PM 10/13/2001]

Vic'89

Great runs and it looks like you got a very fast one from the factory.

You are sure you have no mods , right ?

I ran 13.87 bone stock, so there are L98's out there that can run high 13's from the factory.

Vic

Raistlin

Thanks again for all the input, this forum rocks!

I did forget I put in a K&N air filter in the stock box. That's allways the first thing I do when I get a car. I don't think it adds much hp though, I only change them to K&N so I won't have to replace the filter again. One less maintenence item to get around to. :)

Nomar116

You should still CLEAN the filter or change it every so often. However I suppose a 13.6 is not out of this world impossible with a good rear end... However I wouldnt know... I was happy when after ignition and a few mods I was running 14 flat... That was then though I had to go through alot to make it out of those 14's... Not only is the 13.6 but the poor start says a bit too... no offense :yesnod: But if you can bring down those 60' times watch out... Theres a good couple tenths in there I would think... Again not for sure but especially with slicks..... Thats gettin to LOW 13s on a stock L98....

PeteL

I've done 120 in 4th with my 89, ZF and 3.33 gears. Still pulling.

Think you have some bigs gears in there!

mackeyred96

Thats pretty good. :)