reinhardt02

first off, i have a bone stock 02 z28 w/ 30k miles on it. m6. catback exhaust w/ some kinda glasspack in place of stock muffler (looks like an aftermarket deal, not some redneck butchered ****) and edelbrock shorty headers. i just bought the car a few monthes ago as is.

cruising down the interstate yesterday about 80 mph a 02ish mustang cobra came up behind me. i was in 6th gear and stepped on it, we hit about 90 and he was tight on me. i downshifted to 4th and steady walked away from him, w/ the a/c on! lol. at around 130 mph and approx 5800 rpm i attempted to shift into 5th gear. it gave me a grinding noise and didnt go into gear. did i do something wrong here? is something broken? is this a common issue? what is gonna fix this?

also, driving down the road at around 70 i heard a quiet whirling kinda noise coming from passenger floorboard area (i think). when i left off the throttle it went away. i drove 60 miles one way steady w/ windows down and t-tops out and didnt hear the sound. on the ride home i had t-tops in and windows up and heard this noise. havent crawled under the car yet to look around, so i have no ideas. anyone have any ideas?

and another thing.... i filled the car up before i left for my trip, and filled up again when i got back. i drove 125 miles and used 5 gallons of gas. i drove 100 miles on interstate w/ no traffic at 70 mph approx, had one burst of 80-130, otherwise gentle driving. drove 25 miles around town when i got to where i was going easy-like. the window sticker for the car called out 29 mpg highway. so my question is: is 25 mpg a good overall mileage for the trip?

thanks for the help ya'll

ben

(i posted this in man trans sectin and havent gotten many responses)

Endersshadow

iTrader: (1)

So you have a modified bone stock Z28? That's interesting. I will never understand why people with any amount of modification still claim their cars are "bone stock". It's weird and kind of ridiculous.

reinhardt02

thank you so much for your useful criticism. that definately answers my questions.

johnnybravo

I just took my stock (only mod is skip shift eliminator) 02 TA, 6 spd, 3:42 rear end, on a 180 mile round trip into southern Michigan yesterday. A couple stops, a few small towns to slow down and pass thru, but all highway and some interstate. Hit 80mph around Benton Harbor, still had people passing me. Mostly kept 5 mph over the posted speed limits. Ran with the windows up and t-tops on on the way there, and windows up, t-tops on, AC on for the way back.

Didn't do any hot rodding, drove easy. When I got back home I filled back up right away. Running Sunoco 93. Calculated it out to be 27 mpg.

Considering I was lucky to get 15 mpg highway out of my 72 Cutlass (actually, I never kept my foot out of it), I think 25+ mpg out of these cars are nothing short of phenominal.

Since you did a little playing around and still got 25 mpg, I'd say that's pretty decent.

reinhardt02

good stuff. i use to run a 79 camaro that was lucky to hit 15 mpg highway. usual average mileage was 10-12mpg.

reinhardt02

i thought the same, but the noise faded/went away when i let off the gas.

Bizzles

iTrader: (3)

25mpg for that trip sounds correct. when my car was stock i got 23 on a full tank across PA @ 80mph but it's an A4, so w/ 6 gears ur doing fine at 25mpg.

F-bodies in general make all kinds of weird noises sometimes. no ideas here.

sounds like you just missed the 4-5 shift. Wouldn't worry about it too much if you don't have any problems with it. Might have just gotten a little hot going from wot 6th into 4th then to 5th.

Mumbles

iTrader: (5)

Come on, man. There's no reason to be dick. Read what he meant to say instead of what was typed.

Its a "bone stock" Internal 02 Z28.

A complete Aftermarket Exhaust System isn't exactly "bone stock". I believe what you meant to say is you have a stock LS1 F-body with upgraded exhaust.

Nice kill!

Did you attempt to shift from 4th to 5th very quickly? If so, some grinding and not wanting to go into gear is a common issue with 4th Gen F-bodys. I've had this happen while shifting my Firebird a few times. It has to do with the restricted flow of the factory Clutch Master Cylinder. It can be remedied with the "Drill Mod", but I don't believe this will eliminate the problem completely. I have yet to perform this modification, so I don't have any real world experience to offer. You may want to check out this thread from The Blue Knight...

https://ls1tech.com/forums/manual-tr...der-video.html

It does a very good job of explaining how to remove and reinstall the master cylinder and also how to perform the "Drill Mod".

I have a similar "whirring" or "buzzing" sound when I'm on the throttle that arrived when I installed Longtube Headers, an Aftermarket Y-pipe, and Poly Motor Mounts. It may be the stronger mounts translating some vibration into the body of the car. Who knows? I know it doesn't affect performance, so I'd say its a fair trade for what I gained with the LTs.

Endersshadow

iTrader: (1)

You're welcome. Phrase things correctly and I won't be a dick.

TAtoad

iTrader: (22)

don't believe everything you read. 25's good man, i used to get 27 on a full tank with 300 miles highway, the rest city driving.

udienow

iTrader: (18)

You wont get that great of gas milage driving with the tops off and windows down, esp on the highway... so 25 is good.

As far as your grinding. I think you just let out the clutch too early before you went all the way into gear... i do this sometimes when im driving hella lazy. Its not really a big deal, just hold the clutch in longer and try again. If you didnt miss the gear, then as the above poster said you need a new master cylinder. The problem is the hydralics are not flowing enough fluid at high RPMs and thus make your clutch basically non-existant. This is a very common problem that plagues many m6 guys. I replaced my master cylinder with an upgraded unit from Tick. They are a sponsor here so just search for the Tick Master cylinder or click their link on the right --->

71novaguy

iTrader: (2)

Maybe you tried to shift into reverse instead of 5th? It happens. 27 is pretty good. I've got 29, damn near 30 cruising 75 mph with a couple of trips over 80.

I do agree with this guys statement though. People will say bone stock, but have a tune, ect. If thats not how it came from the factory, its not bone stock. (no need to flame up about "well it has different tires, brake pads, ect")

reinhardt02

i appreciate all the positive feedback ya'll. and i honestly believe u guys need to calm down some about the definition of bone stock. i have noticed the ppl on this forum are kinda disgruntled/pissed off ppl. i am coming from nastyz28.com and those folks are a lot mellower. i am afraid it has something to do with the average age of the vehicle owner. the average 2nd gen owner is older on average than ur typical 4th gen owner.

WSsick

iTrader: (13)

im thinking you might have gone too far and tried to shift into reverse.


so you hung with a cobra racing in OD? unless he was doing the same.

flintwrench69

iTrader: (11)

Maybe its your rear diff thats noisy since it goes away when you let off the gas.

witry

iTrader: (8)

And people wonder why this board is going to ****

like others have said you just missed a gear no big deal, get that new slave cylinder that is bleedable and it will make a world of difference on how the clutch works

and the whole noise deal like mentioned before fbodies just make noise mine makes some noise ive been chasing for a while and still cant find what it is.. just turn the music up or open the cutout

NeedaV8foundation

iTrader: (4)

im with you, he post a simple question and its obvious (no offense) that he isnt into modding cars and someone has to have some smart *** comment about it.

anyways the whine that your hearing is normal, as for not being able to switch gears its probably due to your master cylinder, gm had a crappy design with them and it doesnt allow enough fluid to go into the slave when under high rpms. next time try and wait a few seconds when youve put the peddle to the floor and see if you can change gears then. if it does then its the MC.

Endersshadow

iTrader: (1)

You are also ridiculous. I really wasn't that mean to the guy. My point is valid and I didn't call him some ridiculous name or something. I kept it non personal and just made my point. The reason this board is "going to ****" is because everybody takes **** too personally. Let's all just be friends and help each other out. I apologize for not including help with my criticism OP....but I felt I was on topic with what I said. Like others have said....you missed a gear. Everybody does it.

DukesOfHazard

Read this on installuniversity.com about swapping out spark plugs.

Trouble Shooting: After this plug install if you hear a loud ticking sound when the engine is under load then you should check your gaskets between the AIR pipe and exhaust manifold.

Also, if you hear a ticking sound all the time then you probably have a loose spark plug wire boot on the spark plug.

02ws666

iTrader: (1)

you reason you ground on the 4-5 is because of a shitty mastery cylinder. Get the Ticker performance adjustable one and neverworry about that again. i did that and can actualy shift into 5th now during a race

oh and its an Fbody, its going to make noises. and about the MPG, holy **** thats good with the ttops off. its basicaly a parachute with the ttops off so dont worry about it you did fine on the MPG.