Well I didn't know LS1s had such awesome top end when even stock until last night when I raced a friend's 01' Z28 bone stock 6-speed...I was running 25 lbs of boost exactly with alky and 93 and a 23 degree timing chip in all gears...we went from a 65 mph roll...I was ahead about 2-3 cars the entire time up until about 120 or so when he ever so slightly started gaining on me and closed the gap to 1-2 cars at 130...then I shut her down because I've only hit 130 like 2-3 times in my car ever and will never go any faster than that...needless to say I thought I would really walk him easily...but I guess I have been educated a little? Even stock those things pull hard on the top end! I guess running in OD running out of gear and trying to run that fast on a stock motor with crap heads and cam doesn't help...it felt like the only thing driving my car at that speed was the turbo and I think even that ran out of gas at like 120...lol oh well fun times...
Stock LS1 Camaro gives me a good top end race
- Thread starter d0n_3d
- Start date
Simply put, it's aerodynamics. The Camaro body glides through the air while the GN is a small building with wheels. It takes a tremendous amount of power to overcome it at those speeds. Also the other things you mentioned in regards to the heads & cam. Be glad he didn't have spray or heads. I have seen P&P LS1 heads flow over 300 cfm. Talk about breathing.
703crewchief
Member
- Joined
- Dec 1, 2002
Man, LS1 F-bodies have a top speed of 159 mph! Thats only because of the programmed limiter! Those cars are way more aerodynamic than a Regal, but that "305hp" (Yeah Right) doesn't hurt either.
It's not all aerodynamics. A Stock LS1 (especially a 3.23:1 geared one) would still be in drive up to 130 mph and right in his powerband.
If you let your car shift into OD by itself, it likely fell completely out of the powerband for a second and then had to pull OD.
If you let your car shift into OD by itself, it likely fell completely out of the powerband for a second and then had to pull OD.
It is most certainly a big part of it. There are several cars that make less power than the GN and have higher top speeds because of aerodynamics. Stick your arm out of the window at 100+ mph and you quickly see what happens. With a turbo forcing air into the engine, the GN is still in a good torque powerband, but is far from aerodynamic to overcome the resistance.
Plus with his setup, I'm sure he is making more hp & much more torque than his friends stock LS1 even in OD.
so I'm assuming my car did pretty good competing with an LS1 on the top end??? my friend said that his car was just glued to the road going that fast and doesn't even hesitate going past 130...my car feels like there's an invisible bulldozer pushing up against me at that speed not to mention the car is all over the road and tends to bounce more...kinda scary
oh come on...I still have a little ol V6 here
oh come on...I still have a little ol V6 here
How sure are you?
The GN would need to make 500+ lbft of torque at the rear wheels (not so easy to do) at 3300 RPM (assuming a 110 mph shift) to make only 300 Rear Wheel HP (something that would be easy for even a stock LS1 to do at 5500 RPM).
Aerodynamic differences are WAY OVER RATED. I'm the guy that switched from 3.00:1 to 2.50:1 gears and went 7 mph FASTER in the standing mile because the numbers were better. The theoretical gearing/HP numbers for a GN from 100-130 are worse than an LS1. If the GN had 3.0:1 rear gears, the Numbers would be better for the GN.
I don't say stuff just to say stuff. I promise that I work out the numbers before I post.
My Camaro has an automatic tranny and a 2.73 rear end gear ratio. At 100 mph I'm turning 2500 RPMs; at 120 it's 3000 and very stable, just cruisin'. At the track I hit 3rd gear just before I trap, which is at 105, and I'm almost bone stock (airbox lid). A 6-speed is likely even faster than that. If I had the low-end of an LC2 to go with my top end I would be a happy camper.
buickpower
polytetrafluoroethylene
- Joined
- Jun 27, 2003
drag
I pretty much agree with what you are saying about the gearing, however, I wouldn't discount aerodynamics as playing a significant role. We modeled a gn in FLUENT, and lets just say it wasn't pretty compared to other modern cars, and this was only at 65mph. How did you calculate that rwhp #, was it hp=tq*rpm/5252? because i got lower numbers.
I pretty much agree with what you are saying about the gearing, however, I wouldn't discount aerodynamics as playing a significant role. We modeled a gn in FLUENT, and lets just say it wasn't pretty compared to other modern cars, and this was only at 65mph. How did you calculate that rwhp #, was it hp=tq*rpm/5252? because i got lower numbers.
Re: drag
The Aerodymanics may be 20% worse for a TR vs. a F-body, but from 100-130, this would have less of an effect than the gearing disadvantage. Assume a 350 HP Theoretical GN and a 300 HP theoretical Camaro.
If you use the Road HP numbers from Car and Driver, back in 1986 of 30mph - 7 HP, 50mph - 17 and 70mph - 36 HP and extrapolate that out to 100 and 130, it takes approximately 100 HP to go 100 and 200 HP to go 130 and with 350 HP, would have a Theoretical top speed of about 155 mph.
If the Camaros Aerodymanics were 20% better (a huge difference) it would need only about 80 HP and 160 HP to do the same 100 and 130. This theoretical Camaro would have a top speed of about 156 mph, which is about what a real stock camaro tops out at.
Now lets look at the 100 - 130 mph race:
with the GN with 350 HP and the camaro having 300HP, the GN has 250 HP to accellerate tha car at 100 mph and 150 HP to accellerate tha car at 130 mph.
While the Camaro has 220 HP to accellerate the car at 100 mph and 140 HP to acellerate the car at 130. The easily generated 50 extra HP in the GN trumps any aerodynamic advantage of the camaro. This GN should win this race, Right? but it usually does not.
The problem is that the GN's OD shift at 110 mph (or less) knocks the HP down by about 20% minimum (the sooner the shift, the worse it is), so instead of 250 HP to accelerate the car at 100, it only has 200. By 130 it is getting closer to its power band and may be only 5% down from its peak HP, but by then, the Camaro has made up a huge amount of ground, before it too had to shift into OD.
for the Torque calculations I was rounding and doing the calculations in my head. I said 500+, the actual number at 3300 RPM is around 480 to equal 300 RWHP. MOST manual LS1's have more than 300 RWHP (closer to 320) and 3300 is the "perfect automatic OD shift". If you let the car shift itself at WOT, chances are pretty good you'll have 3100 or 3200 RPM in or even less OD. Suffice to say, this isn't the Ideal contest for a GN.
The Aerodymanics may be 20% worse for a TR vs. a F-body, but from 100-130, this would have less of an effect than the gearing disadvantage. Assume a 350 HP Theoretical GN and a 300 HP theoretical Camaro.
If you use the Road HP numbers from Car and Driver, back in 1986 of 30mph - 7 HP, 50mph - 17 and 70mph - 36 HP and extrapolate that out to 100 and 130, it takes approximately 100 HP to go 100 and 200 HP to go 130 and with 350 HP, would have a Theoretical top speed of about 155 mph.
If the Camaros Aerodymanics were 20% better (a huge difference) it would need only about 80 HP and 160 HP to do the same 100 and 130. This theoretical Camaro would have a top speed of about 156 mph, which is about what a real stock camaro tops out at.
Now lets look at the 100 - 130 mph race:
with the GN with 350 HP and the camaro having 300HP, the GN has 250 HP to accellerate tha car at 100 mph and 150 HP to accellerate tha car at 130 mph.
While the Camaro has 220 HP to accellerate the car at 100 mph and 140 HP to acellerate the car at 130. The easily generated 50 extra HP in the GN trumps any aerodynamic advantage of the camaro. This GN should win this race, Right? but it usually does not.
The problem is that the GN's OD shift at 110 mph (or less) knocks the HP down by about 20% minimum (the sooner the shift, the worse it is), so instead of 250 HP to accelerate the car at 100, it only has 200. By 130 it is getting closer to its power band and may be only 5% down from its peak HP, but by then, the Camaro has made up a huge amount of ground, before it too had to shift into OD.
for the Torque calculations I was rounding and doing the calculations in my head. I said 500+, the actual number at 3300 RPM is around 480 to equal 300 RWHP. MOST manual LS1's have more than 300 RWHP (closer to 320) and 3300 is the "perfect automatic OD shift". If you let the car shift itself at WOT, chances are pretty good you'll have 3100 or 3200 RPM in or even less OD. Suffice to say, this isn't the Ideal contest for a GN.
just to let you guys know...my car is currently putting down at LEAST 450 hp to the rear wheels because of the times i have run so far and the current weight of the vehicle...it all makes sense though...the LS1 breathes WAY better than a GN can on the top end plus you have 2 more gears as to where I was on my 4th and last gear and OD is just a horrible performance gear...so I can see how I got challenged pretty good now...lemme get a solid roller cam and aluminum heads and then we will talk
rookie_LC2
the name is...DOOmass
- Joined
- Dec 31, 2003
the flipside,...
Stock F-body, vs. Powercrappered G-body...from 130 MPH all the way to ZERO.
Stock F-body, vs. Powercrappered G-body...from 130 MPH all the way to ZERO.
I have an 02 M6 LS1 with very light mods, so I'm not 100%-stock, and I know I cannot hang close to a 450rwhp car. If he was that close to you on the 65-120mph run, I'm thinking either he's not stock or your car was not putting down what it usually does. I can see him maybe pulling you in the high MPH if you shifted into OD and his still being in 4th, but his staying 2-3 cars of you from 65-110ish is interesting. I've run heads/cam LS1s (about 400rwhp) and they pull me better than 2-3 cars. Maybe your buddy has a 100 shot, lol.
greg wilson
New Member
- Joined
- Nov 10, 2002
who cares gns are not hwy racers, thats what my c5 is for, i kill ls1s in top end hwy racing, anyone who takes a gn over 125 has a death wish, get a turbo t/a or supra, and you will not leave your buddy by 3 car lengths, but 10 train lengths.
You are lucky to find races with stock LS1s. The clubs around Long Island have a bunch with N2O, superchargers & a few with turbos. An LS1 with a 100 shot usually runs low 12s/high 11s @ 115+ mph with nothing else added, but D/Rs. The shop where we built my car installed a TT setup on a 00 SS and it ran mid 11s @ 125 mph on pump gas and 8 psi on the stock drivetrain.
To say a modified LS1 has no chance against a similarly modified GN is just an opinion. Most GN owners have no experience building either LS1s or Mustangs but are quick to make these types of comments. I own a GN, & do all of the work myself on it, but I'm far from an expert and would never say that a GN can do this or that.
To say a modified LS1 has no chance against a similarly modified GN is just an opinion. Most GN owners have no experience building either LS1s or Mustangs but are quick to make these types of comments. I own a GN, & do all of the work myself on it, but I'm far from an expert and would never say that a GN can do this or that.
A few months back I did a highway run with a 02 6 speed Trans Am.
We are in the same club, and we went to the track together.
He did a 9.00 at 82 mph with street tires. I did a 8.25 with a 87 mph trap speed and MT streets. His car has small mods like air lid and that basic stuff.
On the way home from track we did a aproximately 60-90 run on highway. I was surprised that I couldnt gain anything on him, he stayed with me all the time. So yes, LS1 ARE good highway cars.
Daniel
We are in the same club, and we went to the track together.
He did a 9.00 at 82 mph with street tires. I did a 8.25 with a 87 mph trap speed and MT streets. His car has small mods like air lid and that basic stuff.
On the way home from track we did a aproximately 60-90 run on highway. I was surprised that I couldnt gain anything on him, he stayed with me all the time. So yes, LS1 ARE good highway cars.
Daniel
well guys...apparently I found out why my car wasn't pulling my friends LS1 on the top end...it was because I was running REALLY lean!!! my fuel pump has been going into bypass mode all this time on the very top end...25 lbs of boost and 45 lbs of fuel pressure = 70 lbs WOT fuel pressure and the pump goes into bypass at 70 psi...time to shim the spring!
His numbers are about the same as mine in the 1/8, give or take a little. In the 1/4 I run around 13.5 @ 105. Does that seem like a better 1/4 time/speed than the 1/8 time/speed would indicate or are they about right on? Sorry if my question seems a little confusing.
Similar threads
