Full Version: Horse power and torque gains?
I have a 1995 Firebird Formula. The engine is rated to make 285hp. The car already has flowmasters. I plan on adding an SLP CAI, a comp cam (lift .581/.588), Comp cams (beehive) valve spring set (up to .600 lift), Pacesetter coated headers and offroad y pipe, and NGK TR55 spark plugs. I was wondering if anyone knew about how much horsepower and torque this would make? I also plan on getting a tune because that cam is going to need it.
I would guesstimate around 40 hp.
Probably won't need the PCM modded, becuz the hp gain (40 HP per Tyler, and I think he is right), is not that much. The PCM can probably run around 400 hp. After that, it would be wise to install new injectors and that is when the PCM should be modded, becuz the OEM software generally can't get the larger injectors to close up enough for a decent idle.
But, all this is hypothetical, becuz (fair warning here), doubt if the valves have enough clearance for that cam--they could bottom out on the guides. Also, a cam with that much lift has a tendency to float the roller lifters and increasing valve spring pressure won't stop it. My advice, you didn't ask, but....stick with the LT4 Hot Cam. Enough people on this forum have been running this cam and the facts are in...it's very reliable and works extremely well on the LT1.
But, all this is hypothetical, becuz (fair warning here), doubt if the valves have enough clearance for that cam--they could bottom out on the guides. Also, a cam with that much lift has a tendency to float the roller lifters and increasing valve spring pressure won't stop it. My advice, you didn't ask, but....stick with the LT4 Hot Cam. Enough people on this forum have been running this cam and the facts are in...it's very reliable and works extremely well on the LT1.
QUOTE(Me Too @ Jun 29 2010, 07:23 AM) 
Probably won't need the PCM modded, becuz the hp gain (40 HP per Tyler, and I think he is right), is not that much. The PCM can probably run around 400 hp. After that, it would be wise to install new injectors and that is when the PCM should be modded, becuz the OEM software generally can't get the larger injectors to close up enough for a decent idle.
But, all this is hypothetical, becuz (fair warning here), doubt if the valves have enough clearance for that cam--they could bottom out on the guides. Also, a cam with that much lift has a tendency to float the roller lifters and increasing valve spring pressure won't stop it. My advice, you didn't ask, but....stick with the LT4 Hot Cam. Enough people on this forum have been running this cam and the facts are in...it's very reliable and works extremely well on the LT1.
But, all this is hypothetical, becuz (fair warning here), doubt if the valves have enough clearance for that cam--they could bottom out on the guides. Also, a cam with that much lift has a tendency to float the roller lifters and increasing valve spring pressure won't stop it. My advice, you didn't ask, but....stick with the LT4 Hot Cam. Enough people on this forum have been running this cam and the facts are in...it's very reliable and works extremely well on the LT1.
You are right, and I did some more research and think I will go with the LT4 hot cam. Heck, summit even sells a kit that comes with everything, AND its cheaper than buying it separate. Thanks for all the help!
ps. This is the kit I was looking at : http://www.summitracing.com/parts/NAL-12480002/
Not much difference between those. Here's the problem, and notice how they don't tell you this (buyer beware). The LT1 (God bless it's soul) is an excellent engine, but it has one problem--the weight of the roller lifters and that limits its max rpm potential. That cam has a 112 centerline and that means the hp is shoved way up there in the rpm scale. Any solid lifter cam or even a flat tappet cam with a 112 center has an 8,000+ rpm potential (I know, have built engines like this). While 8,000 rpm sounds like fun, there is no way that the roller lifter can do that--too darn heavy, that means that the full potential of that cam can never be used and all that will happen is that your gorgeous car will lose low rpm (below 3,000 rpm) acceleration. Moreover, if your car has an auto, it is doomed to run hi-stall converters to maximize use of a camshaft that will not allow your engine to run at high rpm (the crankshaft and PCM will never allow it anyway).
And, there's another problem...that rated lift is when using 1.5 ratio rocker arms. If the stock rockers are used, they will probably burn out at the pivots. However, not to worry...(naughty fish), the company doesn't tell you that the roller lifters probably still won't stay on the cam, even though it has less lift. Why, becuz the LT4 Hot Cam only does 525 lift with 1.6 roller rockers, which means it isn't a very high lift cam as high lift cams go (it gets its lift from the 1.6 ratio rockers) and it is designed to track the rollers, and (here's the big AND), the LT4 cam uses a 114 centerline to develop the hp down low which complements the design of the engine and the cam, ignition system, injectors and PCM--that means your engine will be able to use everything it has.
Now, I take it you want some really wicked HP? No problem, all of us like that and approve. The best bet is to use a real LT4 Hot Cam with 1.6 roller rockers, port and polish the heads and use a free flowing exhaust. Mod the PCM program at pcmforless.com (ask for Bob), add 26 lbs/hr injectors and enjoy. It's a simple and painless mod to the engine, the stock ignition system will work perfectly (don't modify it a bit), gas mileage will be acceptable, no rumpity, rumpity exhaust note and expect the hp to be around 425, which is darn near super car performance (It will smoke my sister's Maserati, that's for sure).
For more kick, use titanium valve spring retainers, bronze guides and an Air Flow Research Hydra Rev Kit--guaranteed 6,600 rpm potential (actually, I once took mine to 7,000 rpm and maxed the PCM, but that was risking the crankshaft). Your engine will smoke brand new, 6spd BMW M-5s, and others of that ilk. You just gotta love it. We're talking a low 12 second street car. Several on this forum have built engines just like this and they flat work! Finish your car and go out there and knock off some Mustang GTs and the occasional stupid Cobra.
And, there's another problem...that rated lift is when using 1.5 ratio rocker arms. If the stock rockers are used, they will probably burn out at the pivots. However, not to worry...(naughty fish), the company doesn't tell you that the roller lifters probably still won't stay on the cam, even though it has less lift. Why, becuz the LT4 Hot Cam only does 525 lift with 1.6 roller rockers, which means it isn't a very high lift cam as high lift cams go (it gets its lift from the 1.6 ratio rockers) and it is designed to track the rollers, and (here's the big AND), the LT4 cam uses a 114 centerline to develop the hp down low which complements the design of the engine and the cam, ignition system, injectors and PCM--that means your engine will be able to use everything it has.
Now, I take it you want some really wicked HP? No problem, all of us like that and approve. The best bet is to use a real LT4 Hot Cam with 1.6 roller rockers, port and polish the heads and use a free flowing exhaust. Mod the PCM program at pcmforless.com (ask for Bob), add 26 lbs/hr injectors and enjoy. It's a simple and painless mod to the engine, the stock ignition system will work perfectly (don't modify it a bit), gas mileage will be acceptable, no rumpity, rumpity exhaust note and expect the hp to be around 425, which is darn near super car performance (It will smoke my sister's Maserati, that's for sure).
For more kick, use titanium valve spring retainers, bronze guides and an Air Flow Research Hydra Rev Kit--guaranteed 6,600 rpm potential (actually, I once took mine to 7,000 rpm and maxed the PCM, but that was risking the crankshaft). Your engine will smoke brand new, 6spd BMW M-5s, and others of that ilk. You just gotta love it. We're talking a low 12 second street car. Several on this forum have built engines just like this and they flat work! Finish your car and go out there and knock off some Mustang GTs and the occasional stupid Cobra.
QUOTE(Me Too @ Jun 29 2010, 03:08 PM)
Not much difference between those. Here's the problem, and notice how they don't tell you this (buyer beware). The LT1 (God bless it's soul) is an excellent engine, but it has one problem--the weight of the roller lifters and that limits its max rpm potential. That cam has a 112 centerline and that means the hp is shoved way up there in the rpm scale. Any solid lifter cam or even a flat tappet cam with a 112 center has an 8,000+ rpm potential (I know, have built engines like this). While 8,000 rpm sounds like fun, there is no way that the roller lifter can do that--too darn heavy, that means that the full potential of that cam can never be used and all that will happen is that your gorgeous car will lose low rpm (below 3,000 rpm) acceleration. Moreover, if your car has an auto, it is doomed to run hi-stall converters to maximize use of a camshaft that will not allow your engine to run at high rpm (the crankshaft and PCM will never allow it anyway).
And, there's another problem...that rated lift is when using 1.5 ratio rocker arms. If the stock rockers are used, they will probably burn out at the pivots. However, not to worry...(naughty fish), the company doesn't tell you that the roller lifters probably still won't stay on the cam, even though it has less lift. Why, becuz the LT4 Hot Cam only does 525 lift with 1.6 roller rockers, which means it isn't a very high lift cam as high lift cams go (it gets its lift from the 1.6 ratio rockers) and it is designed to track the rollers, and (here's the big AND), the LT4 cam uses a 114 centerline to develop the hp down low which complements the design of the engine and the cam, ignition system, injectors and PCM--that means your engine will be able to use everything it has.
Now, I take it you want some really wicked HP? No problem, all of us like that and approve. The best bet is to use a real LT4 Hot Cam with 1.6 roller rockers, port and polish the heads and use a free flowing exhaust. Mod the PCM program at pcmforless.com (ask for Bob), add 26 lbs/hr injectors and enjoy. It's a simple and painless mod to the engine, the stock ignition system will work perfectly (don't modify it a bit), gas mileage will be acceptable, no rumpity, rumpity exhaust note and expect the hp to be around 425, which is darn near super car performance (It will smoke my sister's Maserati, that's for sure).
For more kick, use titanium valve spring retainers, bronze guides and an Air Flow Research Hydra Rev Kit--guaranteed 6,600 rpm potential (actually, I once took mine to 7,000 rpm and maxed the PCM, but that was risking the crankshaft). Your engine will smoke brand new, 6spd BMW M-5s, and others of that ilk. You just gotta love it. We're talking a low 12 second street car. Several on this forum have built engines just like this and they flat work! Finish your car and go out there and knock off some Mustang GTs and the occasional stupid Cobra.
And, there's another problem...that rated lift is when using 1.5 ratio rocker arms. If the stock rockers are used, they will probably burn out at the pivots. However, not to worry...(naughty fish), the company doesn't tell you that the roller lifters probably still won't stay on the cam, even though it has less lift. Why, becuz the LT4 Hot Cam only does 525 lift with 1.6 roller rockers, which means it isn't a very high lift cam as high lift cams go (it gets its lift from the 1.6 ratio rockers) and it is designed to track the rollers, and (here's the big AND), the LT4 cam uses a 114 centerline to develop the hp down low which complements the design of the engine and the cam, ignition system, injectors and PCM--that means your engine will be able to use everything it has.
Now, I take it you want some really wicked HP? No problem, all of us like that and approve. The best bet is to use a real LT4 Hot Cam with 1.6 roller rockers, port and polish the heads and use a free flowing exhaust. Mod the PCM program at pcmforless.com (ask for Bob), add 26 lbs/hr injectors and enjoy. It's a simple and painless mod to the engine, the stock ignition system will work perfectly (don't modify it a bit), gas mileage will be acceptable, no rumpity, rumpity exhaust note and expect the hp to be around 425, which is darn near super car performance (It will smoke my sister's Maserati, that's for sure).
For more kick, use titanium valve spring retainers, bronze guides and an Air Flow Research Hydra Rev Kit--guaranteed 6,600 rpm potential (actually, I once took mine to 7,000 rpm and maxed the PCM, but that was risking the crankshaft). Your engine will smoke brand new, 6spd BMW M-5s, and others of that ilk. You just gotta love it. We're talking a low 12 second street car. Several on this forum have built engines just like this and they flat work! Finish your car and go out there and knock off some Mustang GTs and the occasional stupid Cobra.
Thank you so much for the info! That was very helpful! I will be doing something along those lines, I will let you guys know once I figure it out and get started. It may be a bit because (of course) my opti went out. So now I gotta fix that when I find the time. I will keep you posted as to how it all goes. This really was a ton of useful information! And you can bet I will be taking down some mustangs, haha. I do plan on taking it to Gateway a few times to see what it runs once I am all finished. This is the first car I have built and I have really enjoyed it so far (I am 17 and very interested in cars. Not as a profession, but it has always been a hobby. I've helped many a fox bodies be built. I am the only one of my friends who went F-body, and I love it). It is nice to have the forum for help though. If you guys are interested, once I get started I am going to start a blog on youtube and update all the things I am doing and show the steps. I will let you know the URL and all that once I get started. Again, thanks for all the help!
So I think I have decided what I am going to go with. I am going to use this set up unless someone advises me differently haha. And first I have to replace the opti and the intake manifold gasket (fairly sure that is the source of my oil leak).
--SLP Cold Air Intake (and a new cast aluminum elbow)
-Summit LT4 Hot cam kit (http://www.summitracing.com/parts/NAL-12480002/)
-Pacesetter Long Tube Coated Headers (comes with NGK TR55 spark plugs)
-Accel 26lbs/hr Fuel Injectors
-A 160 Degree Thermostat
-3.73 Gears
-Then a tune
-Corbeau Seats and Harnesses (I HAVE to get new seats so I figured I might as well get nice ones)
Then eventually down the road I will do this:
-New Throttle Body
-New Intake Manifold
-The list goes on and on:)
Any suggestions or changes? Just let me know!
--SLP Cold Air Intake (and a new cast aluminum elbow)
-Summit LT4 Hot cam kit (http://www.summitracing.com/parts/NAL-12480002/)
-Pacesetter Long Tube Coated Headers (comes with NGK TR55 spark plugs)
-Accel 26lbs/hr Fuel Injectors
-A 160 Degree Thermostat
-3.73 Gears
-Then a tune
-Corbeau Seats and Harnesses (I HAVE to get new seats so I figured I might as well get nice ones)
Then eventually down the road I will do this:
-New Throttle Body
-New Intake Manifold
-The list goes on and on:)
Any suggestions or changes? Just let me know!
you don't need a bigger throttle body!!!!
and I got screwed by Jegs. The guy told me 1.5 roller rockers would more than help with my cam, said I'd be at about 370hp. I got to Jeff at Carolina Auto Masters, he tuned it, and I am running 300hp at the wheels. BIG let down. I would go with 1.6 roller rockes and bigger springs because you can go as big as you want, but if your springs can't handle that lift, you would still run about stock numbers....or so I was told.
and I got screwed by Jegs. The guy told me 1.5 roller rockers would more than help with my cam, said I'd be at about 370hp. I got to Jeff at Carolina Auto Masters, he tuned it, and I am running 300hp at the wheels. BIG let down. I would go with 1.6 roller rockes and bigger springs because you can go as big as you want, but if your springs can't handle that lift, you would still run about stock numbers....or so I was told.
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