Need less power-241 to 806 worth it?
02-12-2009, 09:05 PM
#21
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Run 87 octane. The computer should see the low octane fuel and retard timing.
Are you allowed to make changes in the motor? Destroker crank maybe?
By the way, I'm pretty sure that you're the first, and probably the last, person to ever make a thread on LS1tech asking how to make less power.
Are you allowed to make changes in the motor? Destroker crank maybe?
By the way, I'm pretty sure that you're the first, and probably the last, person to ever make a thread on LS1tech asking how to make less power.
02-12-2009, 09:33 PM
#23
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Keep the ideas coming. But we aren't allowed to modify the motor, tune the computer, or use a timing tuner. Yes, I understand this goes against just about every other post on this board.
In searching I couldn't find any definitive posts stating how much the 241 heads were worth over the 806. The best I found was the flow chart above, but I don't know enough about that to tell if the reduction in airflow would correlate to much of a change in power.
One time I ran with it with knock sensors unplugged and the peak power numbers were under the limit but the car had terrible throttle response and felt like a dog. It was much better with the knock sensors working and a restrictor.
Next time I go to the dyno I am going to try and take a stock exhaust to see if that makes a difference.
If the 806's would cut 10 rwhp then I would do it. Would also try to find the thickest head gaskets to reduce compression. I also have a 98 model cam in there right now and I could change the cam to the later model that is less aggressive.
Yes, this is on a road racing course and is way to much fun. Check out this youtube vid.
http://www.youtube.com/watch?v=iUe9rBx8mYA
In searching I couldn't find any definitive posts stating how much the 241 heads were worth over the 806. The best I found was the flow chart above, but I don't know enough about that to tell if the reduction in airflow would correlate to much of a change in power.
One time I ran with it with knock sensors unplugged and the peak power numbers were under the limit but the car had terrible throttle response and felt like a dog. It was much better with the knock sensors working and a restrictor.
Next time I go to the dyno I am going to try and take a stock exhaust to see if that makes a difference.
If the 806's would cut 10 rwhp then I would do it. Would also try to find the thickest head gaskets to reduce compression. I also have a 98 model cam in there right now and I could change the cam to the later model that is less aggressive.
Yes, this is on a road racing course and is way to much fun. Check out this youtube vid.
http://www.youtube.com/watch?v=iUe9rBx8mYA
02-12-2009, 09:42 PM
#24
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Easy, just go get a dyno, and tell the dyno operator you want super shitty numbers. And he can change a few correction factors..hah
Show the track officials or whoever the graph that you have the weakest LS1 ever.
Show the track officials or whoever the graph that you have the weakest LS1 ever.
02-12-2009, 09:45 PM
#25
Swapping stock heads for stock heads. As long as its a stock part it is legal.
With the power tables the LT1 is a good package. But I think the weight savings of the Ls1 engine make a better overall package. If I can get the power level down below 280 rwhp then knocking 20 hp off shouldn't hurt my throttle response too much.
If I can get the weight down enough then going with double mufflers at the back is a great idea. I'm thinking of putting the stock y pipe on to choke down the exhuast. I don't think it really matters if you restrict a motor on the intake or the exhuast the net affect should be the same. Except I don't know the perfect exhuast size to maximize the power under the curve to keep the tq up enough. The problem is the LS1 makes such good power above 5k that knocking it down below 260 rwhp knocks my tq down too much. Would be great to tune the computer to dump fuel or pull some timing above 5k and pump up timing below 5k. It would also be much cheaper to tune the car through the computer rather than through hardware. But there are still carbed cars in the classes so they want to keep it fair.
With the power tables the LT1 is a good package. But I think the weight savings of the Ls1 engine make a better overall package. If I can get the power level down below 280 rwhp then knocking 20 hp off shouldn't hurt my throttle response too much.
If I can get the weight down enough then going with double mufflers at the back is a great idea. I'm thinking of putting the stock y pipe on to choke down the exhuast. I don't think it really matters if you restrict a motor on the intake or the exhuast the net affect should be the same. Except I don't know the perfect exhuast size to maximize the power under the curve to keep the tq up enough. The problem is the LS1 makes such good power above 5k that knocking it down below 260 rwhp knocks my tq down too much. Would be great to tune the computer to dump fuel or pull some timing above 5k and pump up timing below 5k. It would also be much cheaper to tune the car through the computer rather than through hardware. But there are still carbed cars in the classes so they want to keep it fair.
02-12-2009, 09:53 PM
#26
What's the heaviest muffler out there that goes in the stock location?
Dyno setting are mandated and checked so everyone uses the same setting and correction factor. Though I still think your numbers would be lower on a hot humid day.
Dyno setting are mandated and checked so everyone uses the same setting and correction factor. Though I still think your numbers would be lower on a hot humid day.
02-13-2009, 03:16 AM
#28
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Unrestricted the car makes around 300 rwhp 325 rwtq. Depending on the restrictor I have had it below 250 rwhp 290 rwtq. Last year I ran a 50 mm restrictor and it made 278 rwhp 313 rwtq. Getting the peak power numbers below the limit isn't a problem but then that hurts the throttle response.
The reason to restrict power is to put a bigger group of cars together and level the playing field. That way LT1 and mustangs have close to the same power. They are also attempting to merge two classes and give the 305 TPI and 5.0 some upgrades like headers and restricting the LS1 more to hopefully put everyone at the same power levels. This way it is a drivers class and isn't just who can spend the most money on engines, suspension, brakes, etc.
Unfortunately we aren't allowed to tune the computers, it must be a stock tune. And before you go down the road of still do it, or how do they check it I'm not going to tune the computer.
Have to run exhuast manifolds, but the rest of your exhuast is unrestricted. I have a custom y pipe with cats with a 3" single exhaust without a muffler. I am thinking the exhuast flows pretty well and is hurting my torque. I would like to knock a little HP off the top end and up my torque so I am thinking of going with a stock exhaust setup.
Everyone has to use an approved dyno, Dynojet ###?, with the same settings. At nationals they have a dyno at the track and cars get tested throughout the week and winners get dynoed right after the race.
The reason to restrict power is to put a bigger group of cars together and level the playing field. That way LT1 and mustangs have close to the same power. They are also attempting to merge two classes and give the 305 TPI and 5.0 some upgrades like headers and restricting the LS1 more to hopefully put everyone at the same power levels. This way it is a drivers class and isn't just who can spend the most money on engines, suspension, brakes, etc.
Unfortunately we aren't allowed to tune the computers, it must be a stock tune. And before you go down the road of still do it, or how do they check it I'm not going to tune the computer.
Have to run exhuast manifolds, but the rest of your exhuast is unrestricted. I have a custom y pipe with cats with a 3" single exhaust without a muffler. I am thinking the exhuast flows pretty well and is hurting my torque. I would like to knock a little HP off the top end and up my torque so I am thinking of going with a stock exhaust setup.
Everyone has to use an approved dyno, Dynojet ###?, with the same settings. At nationals they have a dyno at the track and cars get tested throughout the week and winners get dynoed right after the race.
sounds dumb. 
02-13-2009, 03:44 AM
#30
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No...sounds like they're trying to make it a driver vs driver race, not a who has the most money race. Sounds like a good idea: everybody can drive what they like most as long as the power level is the same.
02-13-2009, 04:23 AM
#31
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IMO swapping to the 806's wouldn't give you the power drop your looking for plus you would need perimiter bolt valve covers aswell.
I would swap back to the later cam and put an LS1 Intake on and then go back to the stock Y pipe, that should get you in the ballpark of -20 HP.
Another thing to look into would be to install a stock early 5.3 cam.
I would swap back to the later cam and put an LS1 Intake on and then go back to the stock Y pipe, that should get you in the ballpark of -20 HP.
Another thing to look into would be to install a stock early 5.3 cam.
02-13-2009, 08:57 PM
#34
Cam-even though mine is an 02 it has the 98 cam as it was more aggressive and used to be a T2 race car in SCCA. Now I'm thinking I should swap the cam back to the 02 truck cam that should lower power and boost torque which is exactly what I need. Thanks for that idea. Couldn't run a 5.3 cam or head as it didn't come on a 5.7 in a Camaro.
I also have a pair of 98 model exhuast manifolds that don't flow as good. So I could put on the LS1 intake, later model truck cam, 806 heads, 98 exhuast manifolds, stock y pipe and muffler setup. The question is all of it worth it to have better throttle response or would just the intake and y pipe take care of the majority?
Also, in looking at newbie tech on here the older models had a throttle body cam that would go to WOT quicker so that could help getting on the gas and coming out of the corners. I also saw that the MAF was smaller on earlier cars.
I like to think that if I did all these things it would get below 280 rwhp without a restrictor on the intake.
And yes, this is designed to be a drivers class so it isn't whoever can spend the most on their car. Since there is only so much you can do to a car the setup, prep, and driver make all the difference rather than the size of your wallet like most racing. Also, it makes for some incredibly close racing.
I also have a pair of 98 model exhuast manifolds that don't flow as good. So I could put on the LS1 intake, later model truck cam, 806 heads, 98 exhuast manifolds, stock y pipe and muffler setup. The question is all of it worth it to have better throttle response or would just the intake and y pipe take care of the majority?
Also, in looking at newbie tech on here the older models had a throttle body cam that would go to WOT quicker so that could help getting on the gas and coming out of the corners. I also saw that the MAF was smaller on earlier cars.
I like to think that if I did all these things it would get below 280 rwhp without a restrictor on the intake.
And yes, this is designed to be a drivers class so it isn't whoever can spend the most on their car. Since there is only so much you can do to a car the setup, prep, and driver make all the difference rather than the size of your wallet like most racing. Also, it makes for some incredibly close racing.
02-14-2009, 10:46 AM
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It sounds to me like making the power levels equal is not their real intention.When they dictate that anyone running a LS1 engine must jump through hoops to reduce their HP/TQ to the power level required.Obviously there must be reasons why they prevent de-tuning (a simple and inexpensive fix) to make all thing equal.To me this appears to be a Mustang dominated format and the LS1 cars are not truely welcome.
02-14-2009, 10:55 AM
#38
The power levels are the same for all cars regardless of a mustang, 3rd gen or lt1. Though some platforms do run a little different weight but it is pretty fair. The LS1 was only allowed last year. Now they are trying to merge the classes and allow the 305 and 5.0 guys a few bolt ons to bring there power up. Some LT1's even have to run a restrictor in the more powerful newer class. In the lower powered class the LT1's restrict down to 230 rwhp 300 rwtq.
This all makes it alot of fun with superclose racing. There isn't one particular car that has a much bigger advantage. Though I would say the 4th gens have an advantage on larger faster tracks and the mustangs are better on tracks with tighter corners.
This all makes it alot of fun with superclose racing. There isn't one particular car that has a much bigger advantage. Though I would say the 4th gens have an advantage on larger faster tracks and the mustangs are better on tracks with tighter corners.
02-14-2009, 11:58 AM
#40
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I would not try to choke hp and torque off with restrictions, bad heads, etc. I would shape the torque curve (and therefore the hp curve) to fit the maximum parameters allowed. The winners in these kind of classes do.
Post #18 is a good way to go. I would try for a cam that would peak 310 lb-ft @ 4400 rpm (260 hp) and then hold the 260 or so hp flat to max rpm you want to run. It probably could be made to be very similar to a "stock" cam as far as duraton and lift.
Post #18 is a good way to go. I would try for a cam that would peak 310 lb-ft @ 4400 rpm (260 hp) and then hold the 260 or so hp flat to max rpm you want to run. It probably could be made to be very similar to a "stock" cam as far as duraton and lift.