View this preview video from the Detroit AutoRama. If you like big cams and loud cars you will dig this clip. Make sure you have a good set of speakers and crank up the sub. Your neighbors won't like you though.
the reason you hear the two supercharged cars RPM pulsating is called boost or blower surge. basically they are not tuned to idle and make too much boost, as the motor leans out the RPMs come up the boost comes up and richens the mixture out and the engine slows down, the RPM's drop low enough to have a lean mixture causing the RPM's to increase, rinse, repeat.
That blower and wild cam sound awesome. I got the same surge from my normally aspirated standard 360 V8 Mopar by advancing the timing and possible vacuum advance changes. Then same again from a HP GM V6 with stage 3 cam, all without any blowers or turbo's. Seriously, I got was a sore neck from the surge and sick of popping the bonnet to prove to folks it was not blown. But i must admit, blower surge does sound better.
I'm glad someone agrees with me! If it were the cam, the mountain motors in prostock cars would be surging. Those cams are HUGE, you only see the surging when a car has a blower.
Man, That Sh-Boom Caddy is the baddest sounding most gorgeous rod I've ever seen. The blower surge was putting so much torque to the rear end, that it was compressing the wheelie bars at every surge. WHAT A RIDE !!!
I've seen 3500hp Top Doorslammers and 7000hp Top Fuellers that idle better than the blown cars in that clip. It may be impressive for your average tyrekicker to see at a show, but if any of those cars went near a track (which I reckon would be rare), everyone there would be telling them to get a new cam. Believe it or not, they'd most likely pick up a few more horses and a quicker ET with a proper cam. That silver Mustang however is absolutely brilliant, and it just sounds so brutal...
The pulsating actually has very little to do with the cam. It is actually created by the butterflies on the intake. Since the supercharger creates a vacuum to the butterflies, it forces them to close completely. Wich in turn starves the engine of air. This causes the vacuum to die down from the engine being close to stalling. Which in turn allows the butterflies to open slightly again, because there is no vacuum keeping them closed. This process keeps happening over and over.
*facepalm* With fixed valve timing, a camshaft is set up to make the most power and torque for a specific engine RPM. When this range is moved to a higher RPM than stock, it affects idle quality. Specifically the idle RPM may not be steady and/or the engine may sound as if it would stall and stop, but it doesnt, hence a "lumpy" cam. and BTW N/A cars also do it not just superchargers
That's because it's the only one, I'm guessing, that actually gets driven and isn't a dust collector. It definitely is tuned and ready to do more than roll off a trailer.
wtf is it with trailer queens? Cars are made to be DRIVEN not just on and off a trailer. A majority of these things would break and puke fluids before even going a mile. Beautiful cars, one and all, but seriously, why have a car you can't drive????/
Also, a lot of guys don't live within a reasonable distance from car shows and it's impractical driving the car, to and from, because of the terrible mileage excessive horsepower tends to bring. They'd have to be stopping too often to refuel.
Is he running on alcohol. Alcohol cars normally have that sporadic loping sound. Plus you normally have to shoot some in the blower to get it started, if I'm correct.
Flames are so overdone. I'm going to have my car painted with a light green haze to look like it's covered with pollen. Also a few spots of bird shit and a dead leaf or two. Maybe I'll use real pollen and bird shit and just clear coat over it. I gotta start patenting these ideas.
Absolutely beautiful looks& sound. Although... I was told a long time ago that revving up before switching off was not good. I used to think it was useful to give a final little blast of charge to the battery. However when you turn off the power, the oil pump stops immediately, and because you revved it first, the pistons are still going up& down, but without any oil pumping: so you're wiping away what should've been left coating everything ready for start-up. Doing it a few time probably doesn't matter, and on occasion adds to the drama of the show (like here); but on yer everyday runner it's not a good idea. If things are different these days tell me, I will stand corrected if needs be.
Wait what? Oil pumps are engine-driven, aren't they? I don't think I've heard of any cars outside of super niche Formula 1 style stuff not having directly engine driven oil pumps
No its NOT called hunting, you get hunting with efi an these cars have machanical injection, what you are hearing is blower surge, its when the mechanical fuel pump is driven off the engine an it builds pressure then purged by the barrel valve to feed the engine fuel an keep it running,when the engine is fed more fuel it raises the rpm an in turn turns the supercharger faster not so creating more boost as its only at idle but letting the engine breath a lil better for those moments till that small amount of fuel is used and the rpms drop again till more fuel is injected an the whole proscess starts again, that combined with a big cam makes the surge more dramatic
You'll know when you hear a full race cam and non of those cars are that extreme.Like the gentleman below said,the blower cars in the video do that naturally,Has nothing to do with the cam.
2002 6.0 swap, prc 2.5 heads, 244 246 cam 106 lsa,m6.... Driving the car below 10 mph the car bucks forward with every lope of the cam so I hold the clutch down when im on public roads with lots of stop signs and stop lights, I have c6 also but it has a 4500 Circle D stall so its very street able.
@akrause, Yes the pro mods do not surge like that, but they also idle a helluva lot higher RPM. It can be tuned out, but you sacrifice some power doing so. The Impala is strictly a show car anyhow, so I'm sure the owner isn't to worried about a little compressor surge! It lurches like that cause of a very soft front suspension.
I can't stand shiny cars that do nothing but look pretty. Screw you ppl that look at that shit and give the owners the impression it's cool. Them things have wheels for a reason, take it outside and get it dirty. More ppl like to see themselves hungry on stuff like this. Besides, cars like that HAVE TO BE OUTSIDE to be enjoyed properly. Can't run them in a show, can't smell them properly, can't hear all the little noises right. Gah, nice cars tho! I have the utmost respect for the guys that spend thousands and break the cars once in a while, THEY got stories to tell though!
obsession PC. when you as a individual spend the crazy amount of money and time on a project can you dictate the outcome. Wish all the money I've spent over the years on cars was dedicated to one that was still in my garage .
LN 125 You probably enjoyed driving the cars though. Not look at the thing in a glass cage and wish it had been cheaper so you could ACTUALLY drive it, no? If you didn't dream about it, you would not even have bought the car in the first place.
+ObsessionPC if you have never taken one apart , completely rebuilt the engine , transmission, rear end and whatever else needed replacing just to do it again because of FUN and done this with many vehicles then I wouldn't expect you to understand . Fun cost's money,i would like to be able to enjoy two of them now but they are long gone and life is different.
+LN 125 +LN 125 Well yeah it costs money, but why spend it, when only you and a few others will ever see what it got you? I have helped with rebuilding a 1967 Camaro, a 2005 Dodge Ram SRT10 and I am doing a Canadian made 1986 Grand Marquis (don't laugh I love that car). All have or will have seen hundreds of man hours, but all of them are on the road with ppl admiring them. I LOVE THAT FACT. I am a technician not just to preserve, but to repair when it breaks. And it breaks when you use it, who cares, it is fun, I understand that. Jay Leno drives all his cars afaik.
+Dan D ....why do you say that? No need for insults brother -> I simply meant that across thousands of hot rods I've stood in front of that turn anywhere from a 12 flat to a 5.85 1/4 mile, ...I've never seen a car lurch like that. Can't you set out your statement and opinion without being derogatory ? Maybe you can't
My old 11 second nitrous 5.0 Mustang had a motor that was pretty close to stock specs as well but with a bit of nitrous and also had a stock rear axle. I could carry some extra tools as well as a pair of axles but I couldn't also bring along an extra motor if I grenaded it. It's just peace of mind for me that I can get it home and not have to worry about fixing it before the track kicks me out for the night.
I love it some ppl think that first car he was giving in the gas to make it surge like that but thats at idle that massive blower does that including the big cam some cars chirp the rear tires just from idling lol
A shaft in the engine on which are the lobes (cams) that operate the valves. The camshaft is driven by the crankshaft, via a belt, chain or gears, at one half the crankshaft speed. One or more camshafts regulate the opening and closing of the valves in all piston engines.
that's a boost surge the blower is so big that it builds boost immediately and give that cam because the intake is getting so much air with the throttle body barely open
If he is or not isn't really important. He is correct. That surge is actually caused by the compressor of the supercharger. Even roots and twin screws can have compressor surge just like a turbo, but unlike a turbo they are belt driven and the surge causes the idle do jump like that. In most cases it can be solved with the right setup, but sometimes it will happen regardless.
I was waiting for someone to catch that. You could have a bone stock cam and it would do the same thing. Guess these guys haven't been around many supercharged rides!!
A lot of people seem to dislike these cars cause they aren’t driven much. Look, a lot of these cars aren’t street legal so that’s a start. Also, most of these cars are pushing hp numbers that dwarfs 1000, so it would be impractical and unsafe to drive them on normal roads. Not to mention gas consumption, and that some of these would be on race fuel. Also, you can daily a car and still have it look as shiny as these cars. Its called some prep work. Spend a good weekend buffing and shining a car, then trailer it over to the show. After the show, go right back to getting down and dirty on the strip
Back ones are for the actual exhaust and the fronts im assuming are for electric cut outs I've seen several people run the electric cut outs to the side like that
