The "recipe" to 500 rwhp with heads and cam.
08-08-2009, 04:53 PM
#284
I don't think you'll find that covered in this thread. If you read the first page, it's about maximizing the power potential of 346ci LS1 engines. The small 3.9" bore does not accomodate larger 2.16" from L92 heads. I haven't seen anything about small bore L92 heads actually being produced, and they certainly were not available when Patrick created this combo.
03-19-2010, 11:44 AM
#290
I haven't read this whole thread yet but am up to page7 and very informative wish I would have read it before I built my motor/truck. I went carb'd vic. jr. aed 750hp-ho my heads are fully worked 853's decked 40 thou. 5 angle valve job had to fly cut the pistons to clear for cam I am running the T-Rex cam. nothing fancy. My drivetrain is a 3800 converter through a TH-400 TCI SFi Flywheel big driveshaft built to have the 1350 u joints, 9in. with 5.13's and a 275/60/15 m/t dr I put it on a dynojet chassis dyno and untuned with junk shorty headers for my S10 it surprised me and put down 385.9rwhp @ 6600 and 339.4rwtq don't remember the rpm. I still haven't gotten to tune it yet but it's still rich as can be.
I am impressed with these numbers for factory ported heads and an old off the shelf cam.
Opinions please or advice?
Truck weighs 2534# with out me.
I am impressed with these numbers for factory ported heads and an old off the shelf cam.
Opinions please or advice?
Truck weighs 2534# with out me.
03-19-2010, 12:07 PM
#291
Heads n Cam Great write up from Pat. G..
Goes to show that the Largest cam does not make the most power throughout the RPM range. Everyone is stuck on MAX HP ! Yet as shown in his later post with a smaller cam it makes more Torque and usable power.
My TA with a small cam (for it's cubic inches), 450 lbs of torque @ 3K RPM's ! It's a rocket off the line and thats what I want. But everyone has different taste...
BTW LS 10, with a weight of 2534 without you, how do you keep it on the ground ? LOL.....
Makes me wanna do another V8 S10
Goes to show that the Largest cam does not make the most power throughout the RPM range. Everyone is stuck on MAX HP ! Yet as shown in his later post with a smaller cam it makes more Torque and usable power.
My TA with a small cam (for it's cubic inches), 450 lbs of torque @ 3K RPM's ! It's a rocket off the line and thats what I want. But everyone has different taste...
BTW LS 10, with a weight of 2534 without you, how do you keep it on the ground ? LOL.....
Makes me wanna do another V8 S10
03-19-2010, 12:33 PM
#292
Great write up from Pat. G..
Goes to show that the Largest cam does not make the most power throughout the RPM range. Everyone is stuck on MAX HP ! Yet as shown in his later post with a smaller cam it makes more Torque and usable power.
My TA with a small cam (for it's cubic inches), 450 lbs of torque @ 3K RPM's ! It's a rocket off the line and thats what I want. But everyone has different taste...
BTW LS 10, with a weight of 2534 without you, how do you keep it on the ground ? LOL.....
Makes me wanna do another V8 S10
Goes to show that the Largest cam does not make the most power throughout the RPM range. Everyone is stuck on MAX HP ! Yet as shown in his later post with a smaller cam it makes more Torque and usable power.
My TA with a small cam (for it's cubic inches), 450 lbs of torque @ 3K RPM's ! It's a rocket off the line and thats what I want. But everyone has different taste...
BTW LS 10, with a weight of 2534 without you, how do you keep it on the ground ? LOL.....
Makes me wanna do another V8 S10
03-19-2010, 01:18 PM
#293
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Exhaust selection:
To make big power with a street motor, you need an exhaust that sucks...literally (David Vizard quote). When running a cam with lots of overlap, backpressure is not your friend. But when building a daily driven street car, too free flowing of an exhaust often means too loud. Not in my case.
You want the best headers you can find. For an LS1 F-body, it would be QTPs or Kooks in 1 3/4" size. For a Vette, the LG Pro Long tubes reign supreme. A high velocity merge collector on the header collector is typically worth some nice gains in the mid-range and is known to squeak out a few extra ponies up high as well.
Merging the twin pipes coming off the headers is a critical item for power and sound quality. Vettes have it easy because an x-pipe easily fits and the sound quality is awesome. F-bodies are handicapped because of space constraints. For 500 rwhp, you want to run dual 3" pipes after the headers and you'll want them to merge into a 4" intermediate pipe. Anything smaller will run the risk of flow loss. Most y-pipes on the market slam the 2 pipes together like this:
When the pipes meet at close to a 90 angle, the flow is going to be lower and the sound is going to rasp and drone at 2000-2300 rpm. By using a Flowmaster merge collector or better, your sound quality will improve since the gasses meet side by side as opposed to ramming into each other. Here are a few pics of my exhaust.
Notice the dual 3" pipes merging into a 4" intermediate pipe, then a 4" cutout. After the cutout, the pipe is reduced to a 3" SLP dual dual catback. Compared to open headers with 20" extensions, my motor lost 1 hp with this y-pipe, but gained 10 rwtq in the 2500-4000 rpm range. From a sound standpoint, the rasp/drone is gone with the better y-merge collector. The difference between running with an open cutout and closed exhaust through the tail pipes is 9.5 rwhp. Not bad at all.
To make big power with a street motor, you need an exhaust that sucks...literally (David Vizard quote). When running a cam with lots of overlap, backpressure is not your friend. But when building a daily driven street car, too free flowing of an exhaust often means too loud. Not in my case.
You want the best headers you can find. For an LS1 F-body, it would be QTPs or Kooks in 1 3/4" size. For a Vette, the LG Pro Long tubes reign supreme. A high velocity merge collector on the header collector is typically worth some nice gains in the mid-range and is known to squeak out a few extra ponies up high as well.
Merging the twin pipes coming off the headers is a critical item for power and sound quality. Vettes have it easy because an x-pipe easily fits and the sound quality is awesome. F-bodies are handicapped because of space constraints. For 500 rwhp, you want to run dual 3" pipes after the headers and you'll want them to merge into a 4" intermediate pipe. Anything smaller will run the risk of flow loss. Most y-pipes on the market slam the 2 pipes together like this:
When the pipes meet at close to a 90 angle, the flow is going to be lower and the sound is going to rasp and drone at 2000-2300 rpm. By using a Flowmaster merge collector or better, your sound quality will improve since the gasses meet side by side as opposed to ramming into each other. Here are a few pics of my exhaust.
Notice the dual 3" pipes merging into a 4" intermediate pipe, then a 4" cutout. After the cutout, the pipe is reduced to a 3" SLP dual dual catback. Compared to open headers with 20" extensions, my motor lost 1 hp with this y-pipe, but gained 10 rwtq in the 2500-4000 rpm range. From a sound standpoint, the rasp/drone is gone with the better y-merge collector. The difference between running with an open cutout and closed exhaust through the tail pipes is 9.5 rwhp. Not bad at all.
04-02-2010, 04:53 PM
#296
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Thanks for the write up, really helps
And makes me glad I choose this Y pipe
http://www.jetex.co.uk/website/image...908976rbox.jpg
And makes me glad I choose this Y pipe
http://www.jetex.co.uk/website/image...908976rbox.jpg
04-18-2010, 11:36 PM
#298
since my budget is kinda small what do you have to say about me getting some #243 heads ported and milled to your specs with a ported fast 102/102 and a custom ground cam. im not looking to make your numbers just as much as possible for my money. right now im running a ported stock throttle body, ls6 intake, ported #853 heads, an mti cam on the stock bottom end, and its breathing through edelbrock victor LTs and TSP duals without mufflers. any help will be greatly appreciated
06-05-2010, 11:07 AM
#300
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wow great writeup thanks..... i am new and just got an ls1 motor, i want to do my motor first then my roller. i want the same setup n.a goal of 500rwhp or more. i was looking into stroking it to a 383, how do you think that would do for me with a 383 and similar setup.