LS2 Dyno Results: Headers, FAST 102
05-01-2012, 06:56 PM
#21
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I've only run the car hard twice, once down my friend's concrete driveway (pre tune), which is pretty long (little over 1/8 mile) -- I couldn't get the tires (nearly new Goodyear RSAs) to stop spinning for a few hundred feet -- and once from 30-65ish in 2nd getting on the highway. Tires got loose there too, but gets up pretty quick.
I'm expecting about 114 or 115 in the 1/4 mile. No idea about the time since I tend to launch soft.
05-01-2012, 09:27 PM
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Hi Derrich,
The reality here is a sizable portion of the gains cam from the intake swap....not the other way around. Headers are typically worth 15 - 20 HP at most (with stock heads and cam)....maybe 15 ft/lbs of torque or so. When you do the overlay I think your going to see close to a 40 ft/lb gain in torque at 4000 RPM's! (a very bonus point in the curve to feel a gain like that).
The reality here is a sizable portion of the gains cam from the intake swap....not the other way around. Headers are typically worth 15 - 20 HP at most (with stock heads and cam)....maybe 15 ft/lbs of torque or so. When you do the overlay I think your going to see close to a 40 ft/lb gain in torque at 4000 RPM's! (a very bonus point in the curve to feel a gain like that).
Are you saying a stock ls2 v1 would dyno well north of 350 stock or are your inferring after other mods are done the headers become a lesser bang for the buck? I have no doubts the c6 platform can yield north of 350 stock but the v1 driveline is a hp leech. See above for my print out which was 1 7/8 kooks w/hi flow cats and tune, everything else on the car was stock except a drop in kn air filter. From the tuner - another ls2 based v1 with obx headers/cai pulled north of 380. Either their dyno is extremely generous or 35-40hp closer to the right number for a good set of headers on a stock ls2. I didn't baseline my ls2 V1 but 335-340 seems about right from other postings and the 370-380 number also seems common for header only ls2 v1's posts.
05-01-2012, 09:45 PM
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That was my dyno graph and just to clarify - that was not a header swap, that was just a re-tune (by a new tuner) after a new boost a pump was installed. The 1 3/4 headers were on before the blower was. When I installed the headers on my stock V I was at ~365-370 rwhp.
05-02-2012, 01:20 AM
#24
Are you saying a stock ls2 v1 would dyno well north of 350 stock or are your inferring after other mods are done the headers become a lesser bang for the buck? I have no doubts the c6 platform can yield north of 350 stock but the v1 driveline is a hp leech. See above for my print out which was 1 7/8 kooks w/hi flow cats and tune, everything else on the car was stock except a drop in kn air filter. From the tuner - another ls2 based v1 with obx headers/cai pulled north of 380. Either their dyno is extremely generous or 35-40hp closer to the right number for a good set of headers on a stock ls2. I didn't baseline my ls2 V1 but 335-340 seems about right from other postings and the 370-380 number also seems common for header only ls2 v1's posts.
What does make for extremely useful info however is changes made on the same dyno and essentially what I am saying is IMO, a larger portion of the OP's gains came from the manifold swap....not the header swap.
I have seen many header swaps on stockish engines....my own Corvette being one of them as I was doing all the typical bolt ons prior to ultimately getting deeper into the engine. While worth more on modified rides complimenting all the other airflow related mods, stock head/cam engines usually see in the vicinity of what I quoted with a long tube header install(about 15-20 HP.....15 ft/lbs of TQ) which in and of themselves are reasonably stout gains and produce a noticeable improvement in the SOTP. I saw 20 HP and 15 TQ on my C5 and it added to the fun factor for sure because the entire curve was lifted up, not just gains upstairs.
That leaves alot left to make up the difference that Derrich actually realized (achieving close to 50 HP and 30-35 ft/lbs of torque with even more gains in torque seen in various portions of the curve that will be easier to see with an overlay of the two runs).
Truthfully, whether we are discussing F-Bodys, Vettes, CTS-V's, etc. the gains seen installing a set of long tubes on basically a stock Gen III longblock (no internal mods) usually fall in the same area from the data I have experienced and seen over the years.
Sorry to sound defensive, but I see so many guys poo-poo the FAST intake for no reason (usually griping about the cost), the bottom line is its a very effective mod if you have the money to spend and can be made even more effective with the right porting and prep work (adding more to the cost and more to the net gains as well). Especially over an LS2 manifold which is arguably the worst performing factory manifold GM ever produced. The LS6 makes more power in spite of it smaller TB opening handicap because the runner design if far more important than the size of the opening to the plenum..
Another novel.....alright Im outta here.....Derrich I expect to see that overlay tomorrow!
-Tony
Last edited by Tony Mamo @ AFR; 05-02-2012 at 02:01 AM.
05-02-2012, 01:33 AM
#25
Launching!
I wanna add my two cents.....
This is my dyno of both my car before cam and after cam layover. The before cam mods were 1-3/4 pacesetters, no cats, magnaflow catback, ported stock manifold, and the stock airbox with a k&n...on a dyno jet.
The after dyno was the above mods with a ported tb, and the cam. I know all dynos read different but since we were talking about the power made i thought i would post mine for comparison.
This is my dyno of both my car before cam and after cam layover. The before cam mods were 1-3/4 pacesetters, no cats, magnaflow catback, ported stock manifold, and the stock airbox with a k&n...on a dyno jet.
The after dyno was the above mods with a ported tb, and the cam. I know all dynos read different but since we were talking about the power made i thought i would post mine for comparison.
05-02-2012, 01:15 PM
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You guys must understand that dyno's, much like flowbenches, all read differently. While in a perfect world it would be nice if they all read the same that statement couldn't be further from the truth. Different brands and different styles of dyno's, not to mention the quality of the test cell or lack there of, all read differently so comparing data from different dyno's is really kind of a fruitless exercise. Its just not scientific at all and having been on many, while some are close, you can still see a really wide spread, especially with chassis dyno's that add more variables than an engine dyno.
What does make for extremely useful info however is changes made on the same dyno and essentially what I am saying is IMO, a larger portion of the OP's gains came from the manifold swap....not the header swap.
I have seen many header swaps on stockish engines....my own Corvette being one of them as I was doing all the typical bolt ons prior to ultimately getting deeper into the engine. While worth more on modified rides complimenting all the other airflow related mods, stock head/cam engines usually see in the vicinity of what I quoted with a long tube header install(about 15-20 HP.....15 ft/lbs of TQ) which in and of themselves are reasonably stout gains and produce a noticeable improvement in the SOTP. I saw 20 HP and 15 TQ on my C5 and it added to the fun factor for sure because the entire curve was lifted up, not just gains upstairs.
That leaves alot left to make up the difference that Derrich actually realized (achieving close to 50 HP and 30-35 ft/lbs of torque with even more gains in torque seen in various portions of the curve that will be easier to see with an overlay of the two runs).
Thanks for the clarification and that makes more sense because a blower engine will typically respond better to exhaust mods than an N/A engine. I didn't have a bunch of time earlier and quickly read your post quickly thinking the overlay you posted was the header swap.
Truthfully, whether we are discussing F-Bodys, Vettes, CTS-V's, etc. the gains seen installing a set of long tubes on basically a stock Gen III longblock (no internal mods) usually fall in the same area from the data I have experienced and seen over the years.
Sorry to sound defensive, but I see so many guys poo-poo the FAST intake for no reason (usually griping about the cost), the bottom line is its a very effective mod if you have the money to spend and can be made even more effective with the right porting and prep work (adding more to the cost and more to the net gains as well). Especially over an LS2 manifold which is arguably the worst performing factory manifold GM ever produced. The LS6 makes more power in spite of it smaller TB opening handicap because the runner design if far more important than the size of the opening to the plenum..
Another novel.....alright Im outta here.....Derrich I expect to see that overlay tomorrow!
-Tony
What does make for extremely useful info however is changes made on the same dyno and essentially what I am saying is IMO, a larger portion of the OP's gains came from the manifold swap....not the header swap.
I have seen many header swaps on stockish engines....my own Corvette being one of them as I was doing all the typical bolt ons prior to ultimately getting deeper into the engine. While worth more on modified rides complimenting all the other airflow related mods, stock head/cam engines usually see in the vicinity of what I quoted with a long tube header install(about 15-20 HP.....15 ft/lbs of TQ) which in and of themselves are reasonably stout gains and produce a noticeable improvement in the SOTP. I saw 20 HP and 15 TQ on my C5 and it added to the fun factor for sure because the entire curve was lifted up, not just gains upstairs.
That leaves alot left to make up the difference that Derrich actually realized (achieving close to 50 HP and 30-35 ft/lbs of torque with even more gains in torque seen in various portions of the curve that will be easier to see with an overlay of the two runs).
Thanks for the clarification and that makes more sense because a blower engine will typically respond better to exhaust mods than an N/A engine. I didn't have a bunch of time earlier and quickly read your post quickly thinking the overlay you posted was the header swap.
Truthfully, whether we are discussing F-Bodys, Vettes, CTS-V's, etc. the gains seen installing a set of long tubes on basically a stock Gen III longblock (no internal mods) usually fall in the same area from the data I have experienced and seen over the years.
Sorry to sound defensive, but I see so many guys poo-poo the FAST intake for no reason (usually griping about the cost), the bottom line is its a very effective mod if you have the money to spend and can be made even more effective with the right porting and prep work (adding more to the cost and more to the net gains as well). Especially over an LS2 manifold which is arguably the worst performing factory manifold GM ever produced. The LS6 makes more power in spite of it smaller TB opening handicap because the runner design if far more important than the size of the opening to the plenum..
Another novel.....alright Im outta here.....Derrich I expect to see that overlay tomorrow!
-Tony
I am sure the fast piece is helping the bottom line but there are so many dyno sheets of headers/tune providing ~30hp on the gen4 ls2 on the v1 platform that its difficult to agree with everything you have stated given the trend.
I agree these dyno's are a crap shoot and based on the most popular technology driveline weight/efficiency affects the numbers(as seen by flywheel upgrades), heck when I dyno ran mine it was wearing heavy snow tires ~4 extra pounds a tire. Does your tuner roam from shop to shop and have a good idea of what dyno is more optimistic than others or is your tuner in house? Would they say yours is known to being less optimistic than others. Do you have dyno days, do those people think your dyno is less optimistic. It just hasn't been the norm for the v1 gen3 or gen4 engines, again from those who post online to only see 20hp. Perhaps we are all getting cooked numbers. I am not trying to scare you off in fact it would be great if more people in the business posted and stated research and secrets like you have done keep the info flowing.
05-02-2012, 08:58 PM
#28
Now I will admit I am much more familiar with Vette's and F-Bodys and how they respond to a typical long tube install (and perhaps the CTS-V's have a more restrictive OEM cast manifold and respond better....I don't know), but I did a search on this forum specifically and didn't see anything like that.
Honestly in the 5 - 10 mins I spent looking there was very little in the way of documentation (before and after dyno overlays) one way or the other although I only looked specifically in the CTS-V section because I felt it would be better than providing data from other vehicles which add a variable.
Anyway, if you have some links to share I would be interested in seeing them but the facts remain even at that figure (30) which I feel is high, that leaves a good margin of gain for the manifold which alot of folks on the net would tell you is a waste of time and money....and that's just not the case, keeping in mind with better heads the manifold swap would have shined alot more.
I still suspect the average gain from a long tube install is much closer to twenty.....especially of we are discussing stock head/cam vehicles but as I said I don't have as much real world experience with the "V"'s to know for sure.
For what its worth in the next 6-12 months or so I plan on purchasing a low mileage used one for my next project cars (a newer boosted model).....its just such a practical real world refined hot rod as opposed to the Vette, which I enjoy, but its not as multi faceted as the CTS-V.
I drove a newer one recently for the first time and was extremely impressed with it....probably one of the smartest cars GM decided to build.
Cheers,
Tony
05-02-2012, 09:57 PM
#29
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Thirty ponies is just alot of power on a stock heads/cam longblock from just a header swap.
Now I will admit I am much more familiar with Vette's and F-Bodys and how they respond to a typical long tube install (and perhaps the CTS-V's have a more restrictive OEM cast manifold and respond better....I don't know), but I did a search on this forum specifically and didn't see anything like that.
Honestly in the 5 - 10 mins I spent looking there was very little in the way of documentation (before and after dyno overlays) one way or the other although I only looked specifically in the CTS-V section because I felt it would be better than providing data from other vehicles which add a variable.
Anyway, if you have some links to share I would be interested in seeing them but the facts remain even at that figure (30) which I feel is high, that leaves a good margin of gain for the manifold which alot of folks on the net would tell you is a waste of time and money....and that's just not the case, keeping in mind with better heads the manifold swap would have shined alot more.
I still suspect the average gain from a long tube install is much closer to twenty.....especially of we are discussing stock head/cam vehicles but as I said I don't have as much real world experience with the "V"'s to know for sure.
For what its worth in the next 6-12 months or so I plan on purchasing a low mileage used one for my next project cars (a newer boosted model).....its just such a practical real world refined hot rod as opposed to the Vette, which I enjoy, but its not as multi faceted as the CTS-V.
I drove a newer one recently for the first time and was extremely impressed with it....probably one of the smartest cars GM decided to build.
Cheers,
Tony
Now I will admit I am much more familiar with Vette's and F-Bodys and how they respond to a typical long tube install (and perhaps the CTS-V's have a more restrictive OEM cast manifold and respond better....I don't know), but I did a search on this forum specifically and didn't see anything like that.
Honestly in the 5 - 10 mins I spent looking there was very little in the way of documentation (before and after dyno overlays) one way or the other although I only looked specifically in the CTS-V section because I felt it would be better than providing data from other vehicles which add a variable.
Anyway, if you have some links to share I would be interested in seeing them but the facts remain even at that figure (30) which I feel is high, that leaves a good margin of gain for the manifold which alot of folks on the net would tell you is a waste of time and money....and that's just not the case, keeping in mind with better heads the manifold swap would have shined alot more.
I still suspect the average gain from a long tube install is much closer to twenty.....especially of we are discussing stock head/cam vehicles but as I said I don't have as much real world experience with the "V"'s to know for sure.
For what its worth in the next 6-12 months or so I plan on purchasing a low mileage used one for my next project cars (a newer boosted model).....its just such a practical real world refined hot rod as opposed to the Vette, which I enjoy, but its not as multi faceted as the CTS-V.
I drove a newer one recently for the first time and was extremely impressed with it....probably one of the smartest cars GM decided to build.
Cheers,
Tony
You had to speak of the V2 now I will be thinking about it again. Don't need a v2 don't need a v2 don't need a v2 luckily it doesn't have a 22+ gallon tank like the new m5 otherwise I would have a v2 and I drive 20k+ a year in all climates and even have a hitch on my v.
05-03-2012, 05:43 PM
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Tuner sent me the overlay, but with the wrong baseline run. Actually, this was the third baseline run...the second netted the higher 336HP number that I posted originally. That said, this gives an idea of the before and after KOOKS headers/FAST 102.
Last edited by dudesweet; 05-03-2012 at 05:50 PM.
06-11-2012, 08:09 PM
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I ended up getting a pull at one of the local tuners in town since I was there getting my DMH cutouts wired up. Turns out the dyno results were nearly identical. Another identical characteristic was the fact that I'm getting a fair amount of jumpiness at the top of my curve as well as a little pull in timing.
What's even more discouraging is that there was a 6.0L GTO that pulled before me with a FAST 102 (not ported by Tony Mamo...or anyone else) and headers...same exact mods as my car plus a catback that pulled 402 RWHP and 392 TQ.
Anyway, here's my run with 0 smoothing. Looks like it wants to crawl higher, and then some timing pull. Ugh!
What's even more discouraging is that there was a 6.0L GTO that pulled before me with a FAST 102 (not ported by Tony Mamo...or anyone else) and headers...same exact mods as my car plus a catback that pulled 402 RWHP and 392 TQ.
Anyway, here's my run with 0 smoothing. Looks like it wants to crawl higher, and then some timing pull. Ugh!
06-12-2012, 11:35 AM
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I'm assuming those STD figures are different due to the weather conditions. When it comes down to it, I don't put a lot of stock into dyno #'s. Rather just a tool to measure relative increases. The real #'s come at the track for me.
06-12-2012, 03:14 PM
#38
The operator would have to change to SAE to see the SAE numbers. Its easy if one has the dlf/drf file and winpep 7 on their workstation to view the run file. and you can then look at any number, make cross hairs, compare other runs...
If he has the file, I can change for him.
I usually print out STD, SAE and an Uncorrected.
In this case, based on the weather conditions, a correction was added of approx 4% for one run and 6 % for the other.
This correction varies as weather (air) varies, as for STD (or the others), there is a formula to bring the hp and tq value to a reference using the Dyno Baro, temperature and other sensors.
Ideally, if all sensors are calibrated correctly, the dyno was operated correctly, removal of tire spin (tied down correctly), regardless of which day, the curve should be the SAME! (except for Uncorrected - as this is your at that DA at that time).
Dyno (same brands) variances are from crap operators, crap maintenance on the actual dyno, crap maintenance of dyno air sensors or inability to operate and configure the software. or heat soaking the engine or lack of or any other little habit. SAE for example is a Standardized Engineering and is accurate or NA combustion engines.
Turbos should ONLY BE UNCORRECTED as a waste-gate allows for PSI to be reached regardless of air density (sea level or denver - your manifold will hit 15psi for example.. just at a different ramp rate. There are other considerations such as leaving the turbo efficiency map or actually hitting the turbo limit.. but I wont get into that.
Adding correction (SAE for example) only falsely adds HP/TQ.
Belt driven blowers is fine for correction, as its fixed based on RPM, unless one is using a wastegate (again) on the intake or a restrictor plate.
Last edited by vmapper; 06-12-2012 at 03:22 PM. Reason: drf file
