Need cam with more BOTTOM END Torque, look at my current cam setup
11-23-2010, 05:26 PM
#1
Need cam with more BOTTOM END Torque, look at my current cam setup I am looking for a cam that will help greatly with more bottom end torque and was looking to see if I can get some input on those cams. I have a stroker cam in my setup and YES i know it may be too big for what I have and over cammed it, YES I KNOW! Just seems like off the line I may be sluggish and then it picks up hard after 3500rpms.
Below is my car setup, track time info, and dyno sheet to look over.
Sponsors Input would be GREAT ALSO!!!!!
Here is my car specs:
Car: 1998 Pontiac Trans Am
Block: LS1 346 cid
Compression Ratio: est. 10.8:1
Heads: Patroit Stage II LS6 243 Heads, 64cc, 2.02/1.57, 225cc, .650 lift springs
Cam: MTI S1 244/244 at .050, .612/.612-inch lift 112 LSA
Rocker Arms: Stock
Pistons: Stock
Crankshaft: Stock
Rods: Stock
Throttle Body: PTM 102mm
Air Induction: FAST 102mm
Fuel Injectors: Ford Motorsports 42 lb
Fuel Pump: Walbro 255
PCM: 2002 PCM Swap
Headers: Pacesetter 1 3/4" Longtubes
Exhaust System: 3in Off Road Y-pipe, No cats, Magnaflow Muffler Pack
Transmission: Rebuilt 4L60E
Torque Converter: Yank SS400
Rear Gears: 3.73 Ratio
My 1/4 mile breakdown:
60ft: 1.707
1/8 MPH: 95.041
1/8 ET: 7.411
1/4 MPH: 115.506
1/4 ET: 11.610
Below is my car setup, track time info, and dyno sheet to look over.
Sponsors Input would be GREAT ALSO!!!!!
Here is my car specs:
Car: 1998 Pontiac Trans Am
Block: LS1 346 cid
Compression Ratio: est. 10.8:1
Heads: Patroit Stage II LS6 243 Heads, 64cc, 2.02/1.57, 225cc, .650 lift springs
Cam: MTI S1 244/244 at .050, .612/.612-inch lift 112 LSA
Rocker Arms: Stock
Pistons: Stock
Crankshaft: Stock
Rods: Stock
Throttle Body: PTM 102mm
Air Induction: FAST 102mm
Fuel Injectors: Ford Motorsports 42 lb
Fuel Pump: Walbro 255
PCM: 2002 PCM Swap
Headers: Pacesetter 1 3/4" Longtubes
Exhaust System: 3in Off Road Y-pipe, No cats, Magnaflow Muffler Pack
Transmission: Rebuilt 4L60E
Torque Converter: Yank SS400
Rear Gears: 3.73 Ratio
My 1/4 mile breakdown:
60ft: 1.707
1/8 MPH: 95.041
1/8 ET: 7.411
1/4 MPH: 115.506
1/4 ET: 11.610
11-23-2010, 06:07 PM
#5
Yeah just lop off 20 degrees of intake duration and you will be set 
But seriously, if you want to shift the power down you are probably going to have to reduce duration on the intake valve... I bet you could make similar power, but a little lower in the rev range with even a low 220's intake duration as long as it is on the right lobe. I don't think making the cam a single pattern would be nearly as important as optimizing the intake valve event... and with regards to the exhaust duration, he might not need that much with his current exhaust setup, but I don't really think that is hindering the midrange power as much as the intake pattern.
But seriously, if you want to shift the power down you are probably going to have to reduce duration on the intake valve... I bet you could make similar power, but a little lower in the rev range with even a low 220's intake duration as long as it is on the right lobe. I don't think making the cam a single pattern would be nearly as important as optimizing the intake valve event... and with regards to the exhaust duration, he might not need that much with his current exhaust setup, but I don't really think that is hindering the midrange power as much as the intake pattern.
11-23-2010, 08:54 PM
#6
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Heres a couple of good options for ya....
https://ls1tech.com/forums/dynamomet...424-396-a.html
https://ls1tech.com/forums/dynamomet...411-388-a.html
https://ls1tech.com/forums/dynamomet...424-396-a.html
https://ls1tech.com/forums/dynamomet...411-388-a.html
11-23-2010, 08:56 PM
#7
There are a couple things going on here that make the low end what it is:
At 112 + 0, your intake valve is closing at 54 degrees ABDC. At slow engine speeds, there is time for the piston to start pushing the mixture right back out the intake valve. It's only after the cylinders start filling well that you start making more power.
10.8:1 is not nearly enough compression for that size cam. You should be running more like 12:1.
With your setup, something like a 228/232 110+4 would make much more power under the curve. It should work well with the available compression, so would be the quickest easiest way to go.
If you must run a larger cam, select a cam that closes the intake valve earlier to trap more of the charge a lower speeds, then then mill the heads and run some thinner gaskets to bump the compression up to 11.3 to 11.5:1. I would mill the heads to 61cc and run a .040 thick gasket, putting compression right at 11.5:1.
For the cam, either a 232/236 110+0 or 234/238 110+0 will pack a lot more punch down low while still keeping much of your current top end charge.
At 112 + 0, your intake valve is closing at 54 degrees ABDC. At slow engine speeds, there is time for the piston to start pushing the mixture right back out the intake valve. It's only after the cylinders start filling well that you start making more power.
10.8:1 is not nearly enough compression for that size cam. You should be running more like 12:1.
With your setup, something like a 228/232 110+4 would make much more power under the curve. It should work well with the available compression, so would be the quickest easiest way to go.
If you must run a larger cam, select a cam that closes the intake valve earlier to trap more of the charge a lower speeds, then then mill the heads and run some thinner gaskets to bump the compression up to 11.3 to 11.5:1. I would mill the heads to 61cc and run a .040 thick gasket, putting compression right at 11.5:1.
For the cam, either a 232/236 110+0 or 234/238 110+0 will pack a lot more punch down low while still keeping much of your current top end charge.
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11-24-2010, 06:59 AM
#10
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Yep....... I LOVE this cam!
Mine made 414/372 on an LS6 top end with a ported stock TB and shitty headers. Made the #'s in my sig. Getting a FAST intake soon. Pretty good for my "Dinky" 224/228 cam.. Drives like a stock cam around town but power comes in at about 2500 rpm and SCREAMS up top! No real bog, but I'm on stock gears too. (M6)
I LOVE this cam!Mine made 414/372 on an LS6 top end with a ported stock TB and shitty headers. Made the #'s in my sig. Getting a FAST intake soon. Pretty good for my "Dinky" 224/228 cam..
Drives like a stock cam around town but power comes in at about 2500 rpm and SCREAMS up top! No real bog, but I'm on stock gears too. (M6)
11-24-2010, 07:06 AM
#11
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I have a brand new Comp LSR/XE-R cam I am selling. I do not see myself putting a cam in this car so might as well pass it on to someone else. I bought it a few months ago from Tony at AFR. Specs are 227/232 .613 .595 on a 114+2 LSA. $300 shipped takes it.
11-24-2010, 10:46 AM
#15
I would not say your cam is necessarily too big but it seems you could benefit from a bigger stall and some 4.10's to make it run harder.
But if you want to dig into the engine, i would have the heads milled to bring the compression up and run a cam in the low 230's on 110 or 111 lsa with a few degrees of advance ground in.
But if you want to dig into the engine, i would have the heads milled to bring the compression up and run a cam in the low 230's on 110 or 111 lsa with a few degrees of advance ground in.
11-24-2010, 12:24 PM
#16
I would not say your cam is necessarily too big but it seems you could benefit from a bigger stall and some 4.10's to make it run harder.
But if you want to dig into the engine, i would have the heads milled to bring the compression up and run a cam in the low 230's on 110 or 111 lsa with a few degrees of advance ground in.
But if you want to dig into the engine, i would have the heads milled to bring the compression up and run a cam in the low 230's on 110 or 111 lsa with a few degrees of advance ground in.
Man guess I am just crazy because I would say over 240* duration and over .600 lift on stock displacement is a bit big, certainly too big for a car that sees the street with any regularity. The whole nomenclature for what is a small v mild v big cam is sort of warped here, IMO.
11-24-2010, 12:28 PM
#17
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I don't know why you care about low-end torque with a
4000RPM stall speed. Maybe your idea of "low end" and
mine are just different. But I doubt you see under 4000RPM
at half pedal or above.
If anything, I'd look to why your torque fades so much
as you go up from 5500, with all those airflow mods in
place. That's where you live, with that converter.
4000RPM stall speed. Maybe your idea of "low end" and
mine are just different. But I doubt you see under 4000RPM
at half pedal or above.
If anything, I'd look to why your torque fades so much
as you go up from 5500, with all those airflow mods in
place. That's where you live, with that converter.
11-24-2010, 12:33 PM
#18
MTI S1 244/244 at .050, .612/.612-inch lift 112 LSA
Man guess I am just crazy because I would say over 240* duration and over .600 lift on stock displacement is a bit big, certainly too big for a car that sees the street with any regularity. The whole nomenclature for what is a small v mild v big cam is sort of warped here, IMO.
Man guess I am just crazy because I would say over 240* duration and over .600 lift on stock displacement is a bit big, certainly too big for a car that sees the street with any regularity. The whole nomenclature for what is a small v mild v big cam is sort of warped here, IMO.
Your not crazy at all, that donkey dick cam has no place in a stock displacement engine. Retire that behemoth in for something along the lines of a 228/232 or 230/234. Better under the curve power and you'll probably end up making more HP and Torque than your current setup. Take some time to search and you'll find tons of setups similar to yours that make as much or more power with a smaller cam.
11-24-2010, 01:11 PM
#20
I don't know why this keeps popping up, but it's not really true. I did heads and cam on a stock bottom end 02 TA for a friend using a TR230 and the TSP stg 2.5 5.3 heads I pulled from my car. The cam was already in when he decided to buy my heads so we left it as is. The car has gone 11.27 with a 1.47 60' full weight with a 220lb driver. He is running a 12 bolt with 4.11's and a 4l60e with a PTC 3500 converter. It still has the stock intake with a ported throttle body but I'm sure there would be gains with a FAST.
I would love to swap the cam for something with identical VE's on the intake side with a 232 or 234 exhaust duration just to see what it will do. I doubt it would be worth the swap but it would be interesting to test and maybe end the debate over the reverse split with ported heads being a bad idea.
I would love to swap the cam for something with identical VE's on the intake side with a 232 or 234 exhaust duration just to see what it will do. I doubt it would be worth the swap but it would be interesting to test and maybe end the debate over the reverse split with ported heads being a bad idea.