How high is it safe to rev stock ls1 threw the traps?
01-28-2010, 12:55 PM
#1
How high is it safe to rev stock ls1 threw the traps? Ok in other words my current problem is that my current set up requires i go into 5th gear and i really want to stay in 4th. The car is a 71 datsun with a turbo ls1 and t56 trans. currently i have a 3.70 rear and with a 6200 redline i can hit 124 in 4th gear which is at least 10 mph shy of what the car traps at, the car stops pulling at 6200 so that is where i have my shift light set for. the tallest tire i can run is 24.8 so a taller tire isnt a option. the tallest easily available gear ratio is 3.54 so i purchased a new rear with those gears and once installed i should be able to hit 130 in 4th at 6200, now the car will probably still trap 135+ so i still need a little more and since gear and tires are out of the question i figured that i need to rev to 6500 across the traps. Has any one ever heard of stock cam and valve springs being wound out that far? I do have ARP rod bolts so im not worried about the stock rods yet. I know i should eventually upgrade the cam and springs but for now i have to run this set up.
01-28-2010, 01:13 PM
#2
Move your rev limiter to 6800 and see if you can get out with that. With stock rod bolts I wouldn't turn it over 7000 if you are trying to get any kind of life out of the motor. We have turned our stock bottom-end HC car to 7500 but if it only lasted 3 or 4 passes we wouldn't be upset about it. 
Jon
Jon
01-28-2010, 01:22 PM
#3
Yeah I would bump it up to 6800 like ^^said. But I would be a little concerned about the springs and pushrods if they are stock, It very easy to put a set in. With your turbo blowing air onto the valve it makes it that much harder for the stock springs to close the valve, get some good dual valve springs and keep those valve in proper operation.
then when time permits you will have the good parts for a cam swap + oil pump if you don't have that now.
BTW what kind of numbers are you putting down? 1/4? 60? sounds like you should be in the 10's
then when time permits you will have the good parts for a cam swap + oil pump if you don't have that now.
BTW what kind of numbers are you putting down? 1/4? 60? sounds like you should be in the 10's
01-28-2010, 01:32 PM
#4
it went 10.4 at 134 spinning badly and using 5th as stated. i hope to hit 10.0 with better traction and staying in 4th. the revlimiter is already bumped to 6800 but i never rev past 6200 due to it not really pulling any more, but i just wanted to be sure that its ok if i wind 4th to 6500. I do have ARP rod bolts and from what i read thats the first thing to go. I was considering putting better valve springs in it, but the push rods require to much tear down right now. can i run the z06 yellow springs and stock push rods and cam and see less float? or would that be a waste of time and cash for the little gain? as for boost working against my valves my hope is that since i am only going to run between 8 and 10 psi that it wont be to much of a issue. but thats why i have you guys to set me straight.
to set me straight.
01-28-2010, 01:42 PM
#5
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installing new pushrods isnt a matter of teardown. you just pull em out when you swap the springs. remember, cam - lifters (inside block), pushrods rocker arms and valve springs, then valves (inside heads) visualize that like a train. you cant pull the lifters without pulling the heads, but you CAN do the pushrods. and i'd reccomend it. cheap insurance.
01-28-2010, 01:50 PM
#6
I've spun the stock valvetrain to 6600. No problems, but no ET gain. Torque drops off too quick at those rpm's (not enough valvespring).
Some have said I was stupid to do so, but they don't know what I know.
Some have said I was stupid to do so, but they don't know what I know.
01-28-2010, 01:51 PM
#7
yeah i was thinking lifters DOH , so it seems like a ls6 cam ,yellow springs and push rods would be a decent upgrade since 6500 is what they bumped the ls6 limiter to and thats where i plan on revving to. to swap the cam dont i need some sort of slider tool to stop the lifters from falling down? I think i will start hunting for a low miles zo6 cam push rod and springs deal for when i do decide to upgrade.
Last edited by lavoy; 01-28-2010 at 02:02 PM.
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01-28-2010, 03:10 PM
#8
yeah i was thinking lifters DOH , so it seems like a ls6 cam ,yellow springs and push rods would be a decent upgrade since 6500 is what they bumped the ls6 limiter to and thats where i plan on revving to. to swap the cam dont i need some sort of slider tool to stop the lifters from falling down? I think i will start hunting for a low miles zo6 cam push rod and springs deal for when i do decide to upgrade.
01-28-2010, 08:58 PM
#14
Only on the 2002 ls6 heads that came ine the z06 cars, any 243 heads that were off a later ls2 car did not have the hollow stem, always check the year if you desire these valves.
To the op, I think the 3.54 will help out quit a bit, even though its just a small gear change. Don't think that the ls1 is a complicated motor, its actually one of the simplest motors around, easier to work on then a brigs and stratton....
I wouldn't say the ls6 cam is a waste of time, he will gain power and keep great street manners, while shifting powerband a couple hundred rpm's higher. But then again a good FI cam can be another boost in power, but he's already trapping 130-134 with traction and rpm issues so maybe its best to focus on those two first.
Just get a list and put all these good parts in the car so you have nothing to worry about.
-Dual valve springs $280 complete kit
-chromoly pushrods $100
-ls2 timing chain, cheap and direct swap, stronger
-ls6 oil pump, $100-$150 depending on brand, or port and shim yours (pm me)
-cam ls6 ($50-$100 used) or newer bigger FI cam $400
-running 9.90 instead of 10.0.....priceless!
To the op, I think the 3.54 will help out quit a bit, even though its just a small gear change. Don't think that the ls1 is a complicated motor, its actually one of the simplest motors around, easier to work on then a brigs and stratton....
I wouldn't say the ls6 cam is a waste of time, he will gain power and keep great street manners, while shifting powerband a couple hundred rpm's higher. But then again a good FI cam can be another boost in power, but he's already trapping 130-134 with traction and rpm issues so maybe its best to focus on those two first.
Just get a list and put all these good parts in the car so you have nothing to worry about.
-Dual valve springs $280 complete kit
-chromoly pushrods $100
-ls2 timing chain, cheap and direct swap, stronger
-ls6 oil pump, $100-$150 depending on brand, or port and shim yours (pm me)
-cam ls6 ($50-$100 used) or newer bigger FI cam $400
-running 9.90 instead of 10.0.....priceless!
01-28-2010, 10:20 PM
#16
Only on the 2002 ls6 heads that came ine the z06 cars, any 243 heads that were off a later ls2 car did not have the hollow stem, always check the year if you desire these valves.
To the op, I think the 3.54 will help out quit a bit, even though its just a small gear change. Don't think that the ls1 is a complicated motor, its actually one of the simplest motors around, easier to work on then a brigs and stratton....
I wouldn't say the ls6 cam is a waste of time, he will gain power and keep great street manners, while shifting powerband a couple hundred rpm's higher. But then again a good FI cam can be another boost in power, but he's already trapping 130-134 with traction and rpm issues so maybe its best to focus on those two first.
Just get a list and put all these good parts in the car so you have nothing to worry about.
-Dual valve springs $280 complete kit
-chromoly pushrods $100
-ls2 timing chain, cheap and direct swap, stronger
-ls6 oil pump, $100-$150 depending on brand, or port and shim yours (pm me)
-cam ls6 ($50-$100 used) or newer bigger FI cam $400
-running 9.90 instead of 10.0.....priceless!
To the op, I think the 3.54 will help out quit a bit, even though its just a small gear change. Don't think that the ls1 is a complicated motor, its actually one of the simplest motors around, easier to work on then a brigs and stratton....
I wouldn't say the ls6 cam is a waste of time, he will gain power and keep great street manners, while shifting powerband a couple hundred rpm's higher. But then again a good FI cam can be another boost in power, but he's already trapping 130-134 with traction and rpm issues so maybe its best to focus on those two first.
Just get a list and put all these good parts in the car so you have nothing to worry about.
-Dual valve springs $280 complete kit
-chromoly pushrods $100
-ls2 timing chain, cheap and direct swap, stronger
-ls6 oil pump, $100-$150 depending on brand, or port and shim yours (pm me)
-cam ls6 ($50-$100 used) or newer bigger FI cam $400
-running 9.90 instead of 10.0.....priceless!
great information thank you. so what push rods and springs work great on stockish lsx cams and dont have a rep for failure ?
and i think i can go 9.90 now if i push it but im barely allowed in the 10s now at my local tracks, i only have a 4 point roll bar not even a 5 point so running 9s would really make them bitchy. in all honesty i will probably turn it down to like 10.50s for most races i run at any way, but even then i really want to just stay in 4th that extra shift gets on my nerves.
Last edited by lavoy; 01-28-2010 at 10:25 PM.
01-28-2010, 10:42 PM
#17
great information thank you. so what push rods and springs work great on stockish lsx cams and dont have a rep for failure ?
and i think i can go 9.90 now if i push it but im barely allowed in the 10s now at my local tracks, i only have a 4 point roll bar not even a 5 point so running 9s would really make them bitchy. in all honesty i will probably turn it down to like 10.50s for most races i run at any way, but even then i really want to just stay in 4th that extra shift gets on my nerves.
and i think i can go 9.90 now if i push it but im barely allowed in the 10s now at my local tracks, i only have a 4 point roll bar not even a 5 point so running 9s would really make them bitchy. in all honesty i will probably turn it down to like 10.50s for most races i run at any way, but even then i really want to just stay in 4th that extra shift gets on my nerves.
Just call on of the sponsers on her such as texas speed their prices a good and the customer server is what keeps me going back. They will be able to hook you up. get the stock lenght 7.4 rods and any type of dual spring they offer or recommend.
Good luck and keep us posted on whether you get booted out of that track or not for hitting the 9's...LOL
01-29-2010, 08:52 AM
#19
LS1Tech Co-Founder
iTrader: (34)
If you are turbocharged and running a stock longblock, I suggest you contact larry@ls1speed.com and see what springs he reccomends. They have a crazy amount of boost experience and can suggest springs that can help out.
