Top speed run

[pnwdan]

Originally Posted by Aqua Blue RS/SS

Why the spoiler out of curiosity? Sure it adds drag but I would think it has to add even a little bit of down force aka. stability at speed. For sure a blade or wickerbill would add some downforce in my mind.

Rear spoiler is for rear down force at speeds in corners not straights. That is why they added the wicker bill to the Z28 for the track

[go_go_gadget88]

Damn SSE 4 2SS, hell of a lot of good firsthand info/experience talking there! I recently started working my way through your build thread, and impressive is definitely in the list of words I have to say about it so far!!



Slightly relevant question to everyone - do you all know if there is more than 1 spot you have to change in the tune to remove the stock speed limiter? My tuner thought he had it bumped way higher than I would ever go, but the car still shuts down at 155. Not that I plan on these speeds much (if at all) but just curious if we missed something?

[Joecruiser]

Originally Posted by SSE 4 2SS

Here is a video of my record pass and a tribute to and for those that helped or supported me along the road to the record...

Sir,
That was a phenomenal video and music...we are all car guys, oh, gals too...
Thank you for sharing your wealth of knowledge with us.

Godspeed to you....beat those pesky health issue like you set the SS record...
Full Throttle!!!!

[1911 1LE]

Robert, thanks for chiming in and explaining things in detail. BTW, the GT was 240.0 at the half. My simple math came up with him gaining 10mph in less than a second on average to 300.4mph.
We going to see you in October?

[frey.199]

Just curious the same modifications people use to achieve good results in a 1/4 mile. Could that help reflect the same top speeds? I'm guessing it's a whole different build if you want top speed over acceleration. Just curious?

[15RS2NV]

If I recall correctly, RJ and BigRedCamaro did 235 mph in Texas.

[1911 1LE]

If I remember correctly Big Red ran over 250

[mikeman]

Originally Posted by frey.199

Just curious the same modifications people use to achieve good results in a 1/4 mile. Could that help reflect the same top speeds? I'm guessing it's a whole different build if you want top speed over acceleration. Just curious?

You'll still need horsepower which is what determines theoretical maximum top speed. The gearing, wheels/tires, suspension and aerodynamics will have to be adjusted appropriately for doing top speed runs though.

[StingrayblueSS]

Originally Posted by SSE 4 2SS

Here is a video of my record pass and a tribute to and for those that helped or supported me along the road to the record...

As I’m headed down track, look at the sky shifting / tilting back and forth... tire spin and the back end trying hard to lead the car down track... you can see it well On the second pass view, looking out the back..

Such an awesome story, what ever happened to Brandy btw?

[Spec]

Originally Posted by SSE 4 2SS

I found the Texas Mile, and there is the Colorado Mile, the Mohave Magnum and Mile, 1.5 and one mile respectively, the Loring Land Speed in Limestone Maine and a few other events around the country.

I’ve been over 225 mph, establishing a world record for the 5th Gen Camaro at the time.

My car is very stable aerodynamically speaking, now power stability is another subject... I’ve spun the tires pretty much 1st through 5th exceeding 200 mph and still fighting the wheel. It’s not the point and shoot run so many think it is. Sideways and spinning at 200 will pull the little guys tight up into your gut... you just gotta make a decision, stick with it or go find something else to do...

Any car is susceptible to lift at given speeds... even those with tons of downforce... watch road course races with most any type of car, and sooner or later all of them will take flight if driven hard enough... bumpy air from other cars, a broken wing, a bounce, hitting another car with open wheels etc...



This is a subjective opinion. Please bare with me... Yes, there is a net loss of downforce at speeds above 130, 100, or even 60 mph. It’s relative and GM would not release a car in this day and age that will “float” enough within its designed speed limitation (155 mph for the SS) to become light enough to be unstable. I’ve seen numerous 5th Gens at and over 200 with nothing substantial done to the ground effects... I’ve got a few tricks I happily pass on to others as I want to push competition and safety over selfish purposes... there are one or two guys in this thread I’ve offered info to... and before I finish this post, you’ll be able to take advantage of those same ideas... I’ll also offer the reasoning behind every clue..



Please don’t post about it on this forum... we still don’t permit the discussion of illegal street activities... there are plenty of tracks...



I grew my cage to match my capabilities... I could duplicate my car for a hella lot less money than I’ve spent... we were a test bed, and several world record holders have benefitted from lessons we learned... including the current 5th Gen record holder...


The general rule of thumb for a 5th Gen is 1000 RWHP to hit 200 in a standing Mile.

I would like to point out, this is not a drag race... it is not a prepped track, and at least in the events I run they do not allow slicks, skinnies, drag radials or the like. You run a DOT approved (stamped) tire and most of the big power cars run a Hoosier Road Racing tire... they suck (read my previous comment about spinning at 200 +) but they are the best tire available. Most cars run a high end Ultra Sport type tire... and for the record, before anyone bashes them, I’ve been over 200 in a standing Mile on GoodYear Eagle F1 Supercar G2 tires... yup, factory rubber on a 20 inch wheel.


Exactly correct... they are bricks, with the frontal area of a 1968 Peterbilt cabover. Ok, it’s not that bad but close...

Let’s discuss acceleration over time... Yes, the Texas Mile and like events are not timed, so to speak but time is an issue.

60 mph, a mile a minute...
120 mph, a mile in 30 seconds...
180 mph, a mile in 20 seconds...
240 mph, is a mile in 15 seconds...

I cover the last 1/4 mile in about or just under 4 seconds... How much does any car accelerate in top gear at 220-230-240 mph in 4 seconds.. There is an exponential increase in power needed for each 0.1 mph at a given speed, and the faster you go, the worse it gets... If none of that has blown your mind, a good friend of mine, Mark Heideker just surpassed 300 mph in a standing Mile in a Ford GT... the car was about 230 mph at the half mile, so in less than 6 seconds, they accelerated another 70 mph in the back half... I don’t have the exact numbers, but someone good at math can determine the time needed to cover a half mile while accelerating from 230 - 300 mph... it is mind boggling and I’ve been fast enough to set and hold a record for a while... I’m in awe of his accomplishment...

Back to the first sentence of the previous paragraph... if I pass a top fuel car, at the 3/4 mile mark doing 200~~ mph, still accelerating, and they launch on a decent pass, I lose the run to the mile...


True statement if you add “help” keep the front end from lifting... It a full system of informed modifications that help prevent the front, or any part of the car from lifting... Without getting into too much technical stuff at the moment, there are high and low pressure zones all over the car, as well as separation boundaries and other low pressure areas.






How much power does the car have, what car is it, what trans and gear ratio is in the car, what temperature is it, what are the track conditions..

I’m a smartarse so please forgive me. The 5th Gen SS will not achieve 170 without tuning work, to at least remove (increase) the speed governor. Mine is set at 355 mph, as opposed to being turned off... I can’t reach the aforementioned speed due to gearing limitations, and possibly the exponential increase in resistance to moving through air... as well as rolling resistance... my car would theoretically achieve 300 mph at the red line in 5th gear.. it has the power, but it would take at least two or maybe a bit more miles to do so... at least with my current transmission it would... With a PPG I could hit it in less than two miles if the car stayed together and on the ground...


Yup, the only shop I’ve ever used.


The spoiler on a Supra is worth 5 mph. I remove my dove tail and install the factory lip spoiler for mile runs. If not medically retiring, I built a high strake spoiler with a adjustable spoiler and a wicker bill but never got the chance to run it... damned heart attack and strokes...

I removed the dovetail primarily because no one at GM ever stepped up the say it would not break off at speeds over 200. It was designed for a car computer limited to 155 mph. I didn’t want to be the guy going down track, 200 mph, spoiler snaps off and 1500 or more lbs of downforce suddenly and completely, or even unevenly if one quarter blade broke off since it’s a three piece, and have the ass end suddenly lift off the ground as the suspension unloads... nope, don’t wanna be that guy...


Exactly... Part of the claim is from folks who gave probably never exceeded 100 mph in a car, driving or riding, and it’s a new sensation, as the cabin noise increases from slip stream air, the car buffets, bouncing in little side to side motions from turbulence, and the field of vision narrows... Driving at high speeds mandates you physically look in specific directions as the field of vision can narrow to very narrow angles at speeds over 150... I can prove this but we have to take a high speed drive in a car...

I personally wouldn’t take a little red wagon to a certain shop on IH 10 west of Houston, but that’s another subject...

And I have to ask, professional driver of what, a truck. If it felt as if it was on ice at 137, check the tires aand alignment, then find another driver, maybe an amateur like me, or number of guys I race with... beyond that, correct, these cars nor any car should be at 137 on public streets, or most “closed” toads...

I love that car...., I went and looked it up, The Big Red camaro went 251.9 in October of 2017, which is when I was in Trnindad having a heart attack, so I missed that event.... that is one sick car... Let me state, I missed two events after my heart attack and I don’t know if he attended them, so I guess it’s possible he ran over 225... EDIT: He did exactly run faster than I ever did by going 251.9 mph... Outstanding....

I think the “Maryland” event you mention may be the Loring Landspeed, in Limestone Maine, at the old Loring USAF, SAC base... like the Mohave Magnum, you can run the mile track and shut down at the half or run the full mile, or you can run 1.5 miles on the long track...

A couple of quick tricks to “help” reduce front end lift...

A vented hood is helpful, though it depends on where the vents are located and how they are designed... too far forward and they are in the high pressure zone at the front of the brick... car, actually potentially forcing more air under the hood.... too far back on the hood and they sit in the high pressure area formed at the base of the windshield, with the same results.

Remove the rubber weather stripping at the top of the fire wall... this will allow a metric crap ton (scientific terminology in the racing world) air to escape from under the hood. In the process, it reduces the high pressure area that builds at the base of the windshield and most of the hood bounce in the process. Some, not all, of the hood bounce is possibly from the rubber weather stripping allowing pressure to build up until it burps past the weather stripping, whereupon the hood would seat back down to repeat the process... so why does GM install it... it keeps road grime and crap from coming out from under the hood to light upon your windscreen.

Think about the billboard your car is pushing through the air as you increase speed. Most call it a firewall... tomato tomatoe... it’s a wall...

Limit the air hitting it by limiting the air allowed in through the grill, both upper and lower grill... tape it off, use plastic inserts and tape those...

Have a friend with a ZL1 come over and offer him some beer. Remove his belly pan, Trace it on a sheet of 1/16th of so aluminum plate, cut it out and use Riv-nuts and form it to your front cradle... some gentle persuasion with a mallet or brass hammer and it’ll fit like your buddies, and help settle the front end...

Install a for real splitter, not this plastic crap held on by two sided foam tape BS used for shine & show cars that never see the road, much less a track...

Don’t be afraid to alter the cosmetics for performance.. there are few fast show cars, and fewer still showy fast cars... I call mine a 25 footer at best... it looks great from 25 feet but any closer, well, it’s a danged race car...

Remove the mirrors for high speed passes... above say 170... it does help... As 1911 said, hold your hand out the window at 170 and you’ll find out roughly how much resistance there is...

Tape the front end but don’t waste effort on the trunk lid or back glass or things like that... tape on front serves multiple purposes, limiting air under the hood, and it keeps the front fascia/bumper cover from breaking off at speed.. bad form in most cases.. it happened to Lingenfelters 2010 on a drag strip at about 165 mph...

Don’t put a lot of thought into spoilers for passes up to say 225.. run the lip spoiler. It will have almost no effect on the car, good or bad... At speeds above say 130, the separation boundary is way above the trunk lid and without a wing (think ZL1 1LE) then the spoiler is doing nothing. It’s a cosmetic passenger...

If you want a spoiler that works, you have to either raise it (wing) or move it back, way back, like further back than a pro stock car. They have slicker bodies and improved separation boundaries... you can improve the potential by running vortex generators but without a wind tunnels for testing, you are making a WAG at best... if you are a for real engineer, then you are making an educated WAG...

If you opt to move it back, say at least a foot behind the spoiler lid, further if you are going faster, then add high or low strakes. These help realign the aim of the car if you get sideways...

I apologize for the novel but figured one big first and then I can attack specific questions as they arise. And no, I’m not an expert, but there is a 1.5 mile long stretch of track in South Texas with a trail of broken parts and lots of lessons learned.. I broke about as many parts as most anyone...

Last point.. if you get into “land speed” racing, be wary... it’s addicting, and dammit expensive to go fast... you can quickly end up with a garage weight in the form of a busted car and a pissed off spouse, or no ride to work... have fun hot lapping a relatively stock Camaro at the mile, or prepare to write lots of checks... I’ve worn out several debit cards... I’ll use myself as an example, I built an 800 RWHP rocket for 30k. To add 1200 + more RWHP took well into 6 figures... and at that power, you break often... and nothing small or insignificant ever breaks... I lost an O2 sensor right off the line, car pulled hard as hell, going 190 at the half mile, while losing 2 cylinders, and both heads... a 100.00 O2 sensor... Go have fun... I’ll come watch... I’m retired from driving her due to the heart attack and three subsequent strokes... I can just barely use my left hand... and my car is a manual...oh, and at our car weight, automatic transmissions don’t hold up to mile racing... not if you make decent power...

Great read...

[1911 1LE]

It truly is, Robert and I only talk at the mile and when we are both at the shop, but you can tell he is very passionate about mile racing, safety, friends and Brandi. I'll let him tell you about her present state, but she will rise to the top again. One way or another.

[PeteD]

Originally Posted by pnwdan

Rear spoiler is for rear down force at speeds in corners not straights. That is why they added the wicker bill to the Z28 for the track

Um, down force is down force. It does not know if it is turning or going straight

[pnwdan]

Originally Posted by PeteD

Um, down force is down force. It does not know if it is turning or going straight

Yes, so?

That's not the point
High speed straight line you need to stop the car from lifting in the front. You dont necessarily want the excessive down force in the rear as much as when you are carving tight corners and you dont want your rear to swing out.

Sent from my SM-N960U using Tapatalk

[Norm Peterson]

Originally Posted by PeteD

Um, down force is down force. It does not know if it is turning or going straight

It also doesn't know that maybe you don't want as much of it when you're going straight as you do when you're turning . . .


Norm