Top Speed Run tonight finally done!

[Evolution1980]

160mph in a 1980

I would say that in order to hit 160 in a daily driver 1980, you'd need HP in the mid 400's and final gearing in the low 3's, upper 2's. It feels that around 150+ you start to incur too much aerodynamic drag to go much faster. Only HP can overcome that obstacle...

 

[mmvette80]

Maybe he gives it a shot of NOS?

 

[Evolution1980]

Maybe he gives it a shot of NOS?

NOS (=) HP, so yes, that could be....
For sake the of this conversation, it doesn't really matter how you get the HP, as long as you get it.

 

[mmvette80]

Doesnt the 80- 82 front lift up in the front like 2.5 inches at 100mph? I wonder what it was doing at 160.

 

[Evolution1980]

Doesnt the 80- 82 front lift up in the front like 2.5 inches at 100mph? I wonder what it was doing at 160.

I don't know...I've never been outside of it at 100mph :L

 

[69MyWay]

I don't know...I've never been outside of it at 100mph :L

:nono Now that is just plain bad. :L

 

[sscam69]

Nice Avatar Chris!

BTW still drooling over your car!

 

[69MyWay]

Nice Avatar Chris!

BTW still drooling over your car!

Thanks. We scanned that pic out of the March Vette mag from the index page. Nikki is a wizard with the image programs. She covered up the number 36 that was in the upper right hand corner and resized it to slap on here as an avatar.

 

[brooks]

my 96 feels light over 140. i have had it over 150 numerious times but just aim it where you want it to go adn it stays steady. in may of 2001 i averaged 155 for 90 miles and the car worked fine. corvettes are really a remarkable vehicle.

 

[sscam69]

Hey Chris

Did they do a cover story in the March issue of Vette Magazine?

I picked up a copy of the Feb. but not the March. Is it out yet?

Went to B&N the other night and didn't see any new issues. I think I am going to check out a few more copies. Seems to be a good mag. Might subscribe.

Frank

 

[69MyWay]

Hey Chris

Did they do a cover story in the March issue of Vette Magazine?

I picked up a copy of the Feb. but not the March. Is it out yet?

Went to B&N the other night and didn't see any new issues. I think I am going to check out a few more copies. Seems to be a good mag. Might subscribe.

Frank

Look for the March 03 on the news stand in a couple of weeks

 

[sscam69]

saweet!!

I guess that Avatars a teaser:L

 

[jayello]

I've only had my 67 up to about 125. Wasn't paying attention to the speed to much I was busy chasing down a mustang GT and whipping him. At that speed with the tires that were on the car it started to get a little light on the front end. Glad I backed off when I did.

I've had my Mark VIII up to 134 though (damn speed limiter, gotta get a chip for it one of these days) I've done this on several occasions and most of the time with my car filled with friends. We have a nice empty interstate out by where I live. The car would easily reach 160+ as its only pulling 3250 RPM's when it reaches the speed limiter and doesn't redline till 6000. It felt extremly stable up at those speeds too. No floating or vibrations at all.

 

[80vette_ca]

Re: 160mph in 1980

Originally posted by Zektor
What have you done to your car!!!???

·350 CID bored and stroke indexed to 357 CID
·Speed Pro Hypereutectic pistons
·Plasma moly piston rings
·Crane Performance Camshaft (454 LIFT, 248 DURATION INTAKE, 244 DURATION EXHAUST)
·Edelbrock Performer intake
·625 Carter Superseries Carburetor
·Advance curve kit in distributor
·Melling high volume oil pump
·Sealed Power 1.5 Ration Rocker Arms
·1.94 Intake and 1.88 Exhaust stainless steel valves
·Port matched head to intake and exhaust
·K&N high flow air filter
Bilstien Performance gas shocks- all four corners

No specs on the tranny yet because I had a lot of work done to it and I haven't got the bragging sheet from my mechanic yet. And by the way the only thing better then knowing how fast you're going is having a bent needle on the speedometer!!

 

[WayneLBurnham]

Don't believe that much HP is needed...

Just saw this thread and read the first page and the last!

My poor POS currently has a "Target" GM crate replacement motor in it, with no mods other than headers (and great exhaust overall), Edelbrock 750 and Performer Intake and Mallory HyFire Igntion. I'd be surprised if the 'plant's putting out 275 peak.

When I had first got the vicious little money pit, the first thing I did was get the maypops off it and some half-way decent V rated meats on it - Michelin Pilot 225R6015's (with some unrememorable series of letters attached...) a few poly bushings here and there, a first brake job and not much else, drive train or suspension wise.

The first time I really convinced myself I had not done another typical "Stupid-Burnham-Good-On-Paper" stunt was when I found a good section of empty highway and saw what this IRS equipped platform really handled like at (for me) absurd speeds.

I was watching the tach - the speedo's not as easy to see and was really more intersted in seeing how the new ignition was working with it's rev limiter set at 6.5K.

I had the top down, left hand on wheel only and let it rip for the first time. I was watching the tach (and for hidden cops ) and paid real attention as it passed 5500. When it hit 6K - which had not taken very long at all - I really glanced over at the speedometer at was astonished to see I was past 145!!!

I had never driven a car that speed before - plenty of good old street-drag mopars and first generation firebirds and such to 120+, at which point you're usually hanging on too tight with both hands fighting suspension problems and HOPING a wheel doesn't just fall off (did I have to say that?).

(That was a very good concern one writer raised - my rear driver wheel broke off at the axle (inner bearing seized) at 80 not 3 months later - with NO warning...)

This 3500 pound chunk of 27 year-old red ink was handling at 145 on the gauge (probably anywhere from 137-150) like a new Caddy sedan at 80!!! When I decided I wasn't dead and didn't have long before I wore some lucky piece of valvetrain out, I tried a right and a left turn of the wheel and it handled - fine!

I didn't stay up there long - 15, 20 seconds - my exit was approaching, luck for a multi-thousand dollar ticket and time to engine destruction was approaching, but I was hooked!
I knew I had chosen the right platform for the monster engine I wanted to build - even if it will cost $10-15K more than a new Z06 when I get there.

Bucket loads of credit and cash later, still no engine work and a switch to a superstrength rear end with 3.73's instead of 3.08's, and still without an OD to allow more ventures up there, I did learn some things from the experience, besides I can't wait to get back there and beyond!

I was not that far from the 160+ mentioned and had accelerated decently all the way there with a much weaker engine - so I am not sure drag is that huge yet. Don't be too sold on the newmobiles' "aerostyling" - that is in large part exactly that - styling - not substance. Those designs are not driven by computer as they'd have us believe, rather a glorified mechanical fashion guru decides on the general look of the half-decade and then the computer work begins to minimize the drag.

The C3's and many other cars of that era and before had relatively low drags compared to even some of the hotter numbers of today - and not so inferior that a riceburner or blackforest special can get to a given speed with 1/3 the HP.

One concern I've heard raised is that the ass end gets light at 165 or so - in part due to lack of directed downforce, lack of effective airdamming up front (mine has this already) and the natural tendency of the IRS to come off of flat-planted-tire-stance when raised even modest amounts should the rear end lift.

A man I met who does impressive things with his 600 cube '80 at silly speeds went so far as to swap to a Ford 9" with 41 spline axles on a 4-link rear and away from the IRS mainly over that last phenomenon. I had thought he did that for the torque handling that the regular IRS's are not really capable of (the same reason I went with a $4K 12 Bolt IRS) but it turned out that was of secondary concern to him since he doesn't drag it much anymore.

I think that higher speed handling would be helped a lot by a recreation of a decent wing like the Greenwood wing - not some ridiculous, non-functional, 4' off the deck rivetted aluminum monstrosity to make a Hondavette. Decent airdams are already available as bolt-ons from the regular supply houses.

Only some tunnel work could tell for sure (it's available for rent I understand - and at a popular price!!!) but I don't think it takes 400 HP to push a slightly modified C3 to 170+ - but handling may need to be adjusted to handle those 160-200 speeds.

I loved the early suggestions on this thread to do a saltflat trip some time for vettes - especially C3's...especially in 29 years when I come up with enough money to finish mine!!! ;stupid

 

[Evolution1980]

Re: Don't believe that much HP is needed...

...My poor POS currently has a "Target" GM crate replacement motor in it, with no mods other than headers (and great exhaust overall), Edelbrock 750 and Performer Intake and Mallory HyFire Igntion. I'd be surprised if the 'plant's putting out 275 peak...
...I had the top down... When it hit 6K - which had not taken very long at all - I really glanced over at the speedometer at was astonished to see I was past 145!!!...This 3500 pound chunk of 27 year-old red ink was handling at 145 on the gauge (probably anywhere from 137-150) like a new Caddy sedan at 80....[rear end gearing] 3.08's, and still without an OD...

I think you might want to have your speedo checked or at least pace 2 other cars and get an average. Taking a basic engine AND the top was down? No way you were near 150. Maaaaybe 137...maybe. I know just taking my tops off increases the drag so much that I'm lucky if I hit 125. The 1975 naturally has a higher drag coefficient than the 1980, it weighs more, your crate engine has less than 300hp, AND you had your top down. I'd definitely get your speedo checked, or tell me where I can find gusts of wind that strong!

[/b]Only some tunnel work could tell for sure (it's available for rent I understand - and at a popular price!!!) but I don't think it takes 400 HP to push a slightly modified C3 to 170+ - but handling may need to be adjusted to handle those 160-200 speeds.[/B]

And I'd have to disagree here as well. Getting any car safely in the 170 range is a feat for only the best tuners. Think how many cars you know that hit 170mph that are streetable ("non-drag setup")? They all are well into the upper ranges of 400-500HP, and using the latest technology and aerodynamics. The ZR1 was closest that I can think of in the vette categeory, and the dynamics of that car far surpasses what one can shoehorn into a slightly modified C3. The C3 would require serious modifications in all aspects to get to and be a safe handling car in the 170mph range.

Just my 2¢...

 

[MoeJr]

Nice run Wayne. Your speedo will be off a bit as the tires u have are smaller diameter than what it had originally. I went to www.ondoperformance.com and plugged in your tire diameter and gear ratio( Iused 3.08 and 3.36 ratios) and got 125 for 3.36 and 136 for 3.08's. Thats flying in a C3 Vert. Strong engine there.

 

[69MyWay]

Due to my 3.55 gears and non over drive trans, I am topped out at 125 or so in my 69. That is screaming at 6,000 RPM. It feels awesome though because you are there in a blur, but it is time to come back down fast because big blocks don't like to live very long over 6,000 RPM.

The sound.....oh, the sound....it is pure nervana :cool

 

[WayneLBurnham]

Thanks for the cool calc 'site!!!

Hadn't seen that before!

Yeah, Evo, that was my point - my engine HAS to be weak as you can get (worse now that I ragged the poor thing out by keeping it at 4K all the time with stock valve springs! ) and I had the top down (top up wouldn't help much there - those convertible tops must look like "air velcro" to an airstream - really would need the hard top on to get a little better flow), nevertheless the thing got up there pretty quickly and could have easily gone more if there were more gears - it's rate of acceleration didn't seem to be slacking off at all.

Oh not only do I not trust the speedometer - I don't trust my reading at higher speed in bad sunlight of a tiny little tach face on the auxillary I put on or the factory that definitely is screwed up - although it is pretty close from when I've pushed it close enough in 2nd to activate the rev limiter. (T400's will override 1st gear at around 5500 or so, but not 2nd, unless you alter them )

Still 136 with no effort other than engine RPM stress under the least favorable conditions does indicate lots of room for an even modest SB - making just in the hp/cube range, which is quite affordable for most budgets.

I would assume the reason most of those higher end production cars - the Z06's, Vipers, Porsche's, new Audi's and such have 400+ HP is to get up there as quick as possible, not merely to be able to get there...

...and I honestly do not have a good feel for how long it took to get up there - it wasn't very long from 70 or 80 though, probably well under 10 secs, but it was very subjective and was months ago. With a real engine it would have occurred very quickly indeed.

Good handling, as you mentioned, is a WHOLE other concern - the one that concerns me the most.

'69 I feel your pain - TRUST ME!!! In fact I SO feel your pain you should just ship out that 'ole ragged out, no-good, low-speed dinosaur big block TODAY!!!
[subliminal suggestion mode: ON]
SEND IT TO TEXAS...BE DONE WITH IT...GET A 305...IT'S ALL YOU NEED...GIVE IT TO A NEEDY FAT GUY..."ENGINEFARE - AN IDEA WHOSE TIME HAS COME...."
[subliminal suggestion mode: OFF]

:s :s :s

I really do feel your pain with the 3.73's now and the crate motor having this annoying habit of venting a nice thick plume of smoke out the cowl from oil squeezing out the loose dipstick and onto the passenger headers at any sustained 5K + now!!! (Reminds me I have to put the new one in tomorrow!) I don't think I can get past 115 right now... :cry