Massive dyno testing session.....revealed
06-20-2006, 11:36 AM
#1
Massive dyno testing session.....revealed We recently had the chance to engine dyno about 7 sets of heads back to back with 10 different cams, two different sets of headers and two intakes. This is the type of testing people on here have talked about for years but I don't think anyone has pulled off.
The top 4 sets of heads were the new TFS 215cc head with 13.5 degree valve angle and 64cc chamber. Our 5.7, Stg 1, 225cc intake port with 61cc chamber, our 5.3, Stg 1.5, 225cc intake port with 63cc chamber and then a leading competitors 205 head, which out of the box chamber measured at 66cc.
The headers were a set of Hooker 1 3/4" and a set of Kooks 1 7/8", the intakes were a LS6 and a Fast 90/90
This is NOT a heads up dyno test so anyone that wants to flame please refrain, because that is not what this is about. We simply tested the heads the way they normally come or are shipped.
The results surprised even me, we felt that there would be a 20-30 HP difference in this group of heads, the difference was 10 HP, from best to worst, and the head with the least compression made the worst HP. The heads all had about the same spread in HP with the LS6 intake or the Fast 90/90. All heads made 25+ HP more with a Fast 90/90 attached.
The engine was a GM crate engine that with headers made 370 HP, with tuning it made 400 HP, with the best head, biggest cam (232/236), Fast intake it made 535 HP, so about 165 HP gain not counting headers.
When this combo was tested with the smallest cam (216/220) it made 515 HP
The TEA heads with the smaller 1.55 exhaust valves liked the bigger headers and made more power everywhere, the TFS heads with their 1.57 exhaust valves didn't care and the 205 head with the 1.60 valves did not like the big headers, which also carried the biggest exhaust port volume at 88cc.
Lastly was valve drop, which was measured from the deck of the head to the valve. This is VERY important to anyone that doesn't want to flycut pistons. A stock head has about .150" valve drop, the TEA 5.3 Stg 1.5 was .100", the TEA 5.7 Stg 1 with stock valves and milled .030" was around .130", the 205 head was .120" and the TFS was .155" So you can see the winner of the piston to valve clearance contest is clearly the TFS. With more P to V then a stock head and more compression, this is what the big cam guys would want who don't want to flycut pistons.
What I came away from this testing with was
#1. Something I have always said is there is not that big of a difference in power between cams with a ported head, 20 HP from smallest to largest is not a big spread in my opinion. That's why on our chassis dyno a TR 224 cam had made within 10 RWHP of the best cam we tested, this is basically what we saw on the engine dyno.
#2. If a guy is willing to run big compression (61cc or 11:1+), a cheap head (Stg 1) will outpower the best of the best head with stock compression, I have included power curves for the 2 heads both with Fast intakes and then the much more expensive 205 with a LS6 to show the power difference. Once again this is not a heads up test, simply a comparison between different approaches to making power.
#3. The worst heads we tested power wise, once outfitted with a Fast 90/90 made almost the same HP as the best head with a LS6.
#4. In my opinion a guy is far better off with a $1000 set of the TEA Stg 1 heads and a Fast 90/90 then the absolute best head made with a LS6, which is completely contrary to what I use to preach.
#5. I have a theory for the exhaust side of the engine that says the scavenging that is being done is a bell curve. Meaning too little or too much makes less power, and hitting the sweet spot is the key. The things that effect the scavenging is the exhaust port volume, valve diameter, exhaust duration, header diameter and primary tube length. This is why there is no single magic header, or collector or anything else your going to put on the exhaust side that is ALWAYS going to make more power, it's just not going to happen.
The graphs are the TEA Stg 1 heads versus the aftermarket 205 heads both with Fast intakes, then the TEA Stg 1 heads with a Fast 90/90 versus the aftermarket 205 with a LS6.
The second graph represents about the same cost in head/intake package, with the TEA Stg 1 heads at $999 and a Fast 90/90 at around $1200, then the aftermarket 205 heads at $2200 assuming you already have a LS6 intake.
Two notes about the Stg 1 heads, they can only be done from a 241 casting and they have made 450+ RWHP with a LS6 intake.
The top 4 sets of heads were the new TFS 215cc head with 13.5 degree valve angle and 64cc chamber. Our 5.7, Stg 1, 225cc intake port with 61cc chamber, our 5.3, Stg 1.5, 225cc intake port with 63cc chamber and then a leading competitors 205 head, which out of the box chamber measured at 66cc.
The headers were a set of Hooker 1 3/4" and a set of Kooks 1 7/8", the intakes were a LS6 and a Fast 90/90
This is NOT a heads up dyno test so anyone that wants to flame please refrain, because that is not what this is about. We simply tested the heads the way they normally come or are shipped.
The results surprised even me, we felt that there would be a 20-30 HP difference in this group of heads, the difference was 10 HP, from best to worst, and the head with the least compression made the worst HP. The heads all had about the same spread in HP with the LS6 intake or the Fast 90/90. All heads made 25+ HP more with a Fast 90/90 attached.
The engine was a GM crate engine that with headers made 370 HP, with tuning it made 400 HP, with the best head, biggest cam (232/236), Fast intake it made 535 HP, so about 165 HP gain not counting headers.
When this combo was tested with the smallest cam (216/220) it made 515 HP
The TEA heads with the smaller 1.55 exhaust valves liked the bigger headers and made more power everywhere, the TFS heads with their 1.57 exhaust valves didn't care and the 205 head with the 1.60 valves did not like the big headers, which also carried the biggest exhaust port volume at 88cc.
Lastly was valve drop, which was measured from the deck of the head to the valve. This is VERY important to anyone that doesn't want to flycut pistons. A stock head has about .150" valve drop, the TEA 5.3 Stg 1.5 was .100", the TEA 5.7 Stg 1 with stock valves and milled .030" was around .130", the 205 head was .120" and the TFS was .155" So you can see the winner of the piston to valve clearance contest is clearly the TFS. With more P to V then a stock head and more compression, this is what the big cam guys would want who don't want to flycut pistons.
What I came away from this testing with was
#1. Something I have always said is there is not that big of a difference in power between cams with a ported head, 20 HP from smallest to largest is not a big spread in my opinion. That's why on our chassis dyno a TR 224 cam had made within 10 RWHP of the best cam we tested, this is basically what we saw on the engine dyno.
#2. If a guy is willing to run big compression (61cc or 11:1+), a cheap head (Stg 1) will outpower the best of the best head with stock compression, I have included power curves for the 2 heads both with Fast intakes and then the much more expensive 205 with a LS6 to show the power difference. Once again this is not a heads up test, simply a comparison between different approaches to making power.
#3. The worst heads we tested power wise, once outfitted with a Fast 90/90 made almost the same HP as the best head with a LS6.
#4. In my opinion a guy is far better off with a $1000 set of the TEA Stg 1 heads and a Fast 90/90 then the absolute best head made with a LS6, which is completely contrary to what I use to preach.
#5. I have a theory for the exhaust side of the engine that says the scavenging that is being done is a bell curve. Meaning too little or too much makes less power, and hitting the sweet spot is the key. The things that effect the scavenging is the exhaust port volume, valve diameter, exhaust duration, header diameter and primary tube length. This is why there is no single magic header, or collector or anything else your going to put on the exhaust side that is ALWAYS going to make more power, it's just not going to happen.
The graphs are the TEA Stg 1 heads versus the aftermarket 205 heads both with Fast intakes, then the TEA Stg 1 heads with a Fast 90/90 versus the aftermarket 205 with a LS6.
The second graph represents about the same cost in head/intake package, with the TEA Stg 1 heads at $999 and a Fast 90/90 at around $1200, then the aftermarket 205 heads at $2200 assuming you already have a LS6 intake.
Two notes about the Stg 1 heads, they can only be done from a 241 casting and they have made 450+ RWHP with a LS6 intake.
Last edited by Brian Tooley Racing; 06-20-2006 at 01:44 PM.
06-20-2006, 12:36 PM
#3
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Great info! 
What cam were you using for the 2 dyno graphs?
To me this just goes to show that a well thought out combo will outperform one that's had more money then then thought thrown at it. Considering what can be done to a traditional SBC with 23 degree heads that may flow 290 cfm on a happy flowbench, there is certainly more to power then big 330cfm heads
Jason
What cam were you using for the 2 dyno graphs? To me this just goes to show that a well thought out combo will outperform one that's had more money then then thought thrown at it. Considering what can be done to a traditional SBC with 23 degree heads that may flow 290 cfm on a happy flowbench, there is certainly more to power then big 330cfm heads
Jason
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06-20-2006, 01:30 PM
#11
Originally Posted by Brian Tooley
#4. In my opinion a guy is far better off with a $1000 set of the TEA Stg 1 heads and a Fast 90/90 then the absolute best head made with a LS6, which is completely contrary to what I use to preach.
06-20-2006, 01:35 PM
#12
your saying leading competitors 205 head,do you mean AFR 205 heads? this is great info,it does seem the ls1 likes more compression to make power. i had a set of speed inc's r.g.r st2 ported heads and when i added the leading competitors 205 head (AFR 59cc) i gained 40hp. another 30hp with the fast 90mm and cam swap.
06-20-2006, 01:39 PM
#13
Originally Posted by SideStep
I would like to have seen the 205 heads with a same size combustion chamber as the STG1 heads, for a more level comparison... I do not know of anyone sticking with 66cc chambers if the VEs permit....
06-20-2006, 03:40 PM
#16
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Compression adds a whole lot of power no doubt. Power is dependant on cylinder pressure and piston speed.
My 427 N/A made 500 rwhp/500 rwtorque at only 6,000, with a very mild .575/.578 114 232/236 hydralic cam and only a 10.3 to 1 compression. vs. the typical 427, 12:1 compression and .612/.612+ 244/244+ cams that many shop put out. The motors just do not last over time. The cam loobs alone wear badly.
The best heads are still limited by the MAF, TB, intake and exhaust which is why I just kept my well ported LQ9's that flow well across the board and I just ran some turbo's.
A lot guys/vendors will try a get you to relieve your pocket books BIG for 10 rwhp.. and thats a maybe.
Sure you can get heads that flow great to .700. How many guys are running custom Hogan Manifolds, .700 lift solid rollers, 100+ MM TB's, No Maf, Straight thru 3" exhaust dedicated track cars that are broken down every 2,000 miles? There are a few (usually shop cars or mechanics), but this does not dictate the market as whole. Using my example above, what do I care, what the heads flow at .625+?
I saw one local test where a low dollar brand did just as well as high dollar brand as well.
Sex sells though. Food for thought.
Brian thanks for the study and notes.
My 427 N/A made 500 rwhp/500 rwtorque at only 6,000, with a very mild .575/.578 114 232/236 hydralic cam and only a 10.3 to 1 compression. vs. the typical 427, 12:1 compression and .612/.612+ 244/244+ cams that many shop put out. The motors just do not last over time. The cam loobs alone wear badly.
The best heads are still limited by the MAF, TB, intake and exhaust which is why I just kept my well ported LQ9's that flow well across the board and I just ran some turbo's.
A lot guys/vendors will try a get you to relieve your pocket books BIG for 10 rwhp.. and thats a maybe.
Sure you can get heads that flow great to .700. How many guys are running custom Hogan Manifolds, .700 lift solid rollers, 100+ MM TB's, No Maf, Straight thru 3" exhaust dedicated track cars that are broken down every 2,000 miles? There are a few (usually shop cars or mechanics), but this does not dictate the market as whole. Using my example above, what do I care, what the heads flow at .625+?
I saw one local test where a low dollar brand did just as well as high dollar brand as well.
Sex sells though. Food for thought.
Brian thanks for the study and notes.
06-20-2006, 05:30 PM
#18
Brian,
Welcome to Aruba!
You should have done this comparison 2 years ago when the AFR 205's first came out $$$$$$$$
Better late than never though. Maybe you should start porting FAST intakes also. Check out Tony's most recent write up about the FAST intake. Enjoy:
D.A. 
Welcome to Aruba!
You should have done this comparison 2 years ago when the AFR 205's first came out $$$$$$$$Better late than never though. Maybe you should start porting FAST intakes also. Check out Tony's most recent write up about the FAST intake. Enjoy:
Originally Posted by Tony Mamo @ AFR
FAST 78 out of the box with a bone stock 78 mm TB worth approx. 6-8 RWHP
A well shaped epoxied stock TB worth another 3-4 RWHP on that same intake.
An unported FAST 90 set-up worth an additional 3-4 over the PORTED 78 set-up.
Tack on another 5-10 RWHP for ported (correctly) 90 mm package for the ultimate results and of course the most greenbacks spent....no surprise there. What's interesting is the gains are very similar whether you are talking about a combination that puts down 375 RWHP or 475 RWHP, but as you start stepping up from there the ported FAST 90 set-up could show you even more....airflow is at a premium once your approaching 600 flywheel HP (over 500 to the tires) and the manifold starts to become a larger and larger restriction.
Tony M.
PS....To better more directly answer your original question, a 90 mm set-up will be worth an additional 3-4 ponies over the same set-up with a ported 78 mm TB. Considering the 90 mm aftermarket TB's have come down a little in price, I would tell you just to step up and go with the 90....if you already have a Shaner or another well executed 78 mm TB, you may deem the extra 3-4 HP a 90 mm set-up could provide not worth it from a HP per dollar scenario....although while $125 per pony isn't cheap, its not a ludicrous amount to spend once you have hit all the other details (much like an EWP.....$500 gets you 5 extra ponies). Not to mention you could sell your ported 78 TB which now cuts the HP per dollar in half and IMO now makes the decision to step into a 90 a no-brainer. To summarize...buy the 90
A well shaped epoxied stock TB worth another 3-4 RWHP on that same intake.
An unported FAST 90 set-up worth an additional 3-4 over the PORTED 78 set-up.
Tack on another 5-10 RWHP for ported (correctly) 90 mm package for the ultimate results and of course the most greenbacks spent....no surprise there. What's interesting is the gains are very similar whether you are talking about a combination that puts down 375 RWHP or 475 RWHP, but as you start stepping up from there the ported FAST 90 set-up could show you even more....airflow is at a premium once your approaching 600 flywheel HP (over 500 to the tires) and the manifold starts to become a larger and larger restriction.
Tony M.
PS....To better more directly answer your original question, a 90 mm set-up will be worth an additional 3-4 ponies over the same set-up with a ported 78 mm TB. Considering the 90 mm aftermarket TB's have come down a little in price, I would tell you just to step up and go with the 90....if you already have a Shaner or another well executed 78 mm TB, you may deem the extra 3-4 HP a 90 mm set-up could provide not worth it from a HP per dollar scenario....although while $125 per pony isn't cheap, its not a ludicrous amount to spend once you have hit all the other details (much like an EWP.....$500 gets you 5 extra ponies). Not to mention you could sell your ported 78 TB which now cuts the HP per dollar in half and IMO now makes the decision to step into a 90 a no-brainer. To summarize...buy the 90
Last edited by gollum; 06-20-2006 at 05:58 PM.
