just overlaid the 3.4L and 3.6L dyno charts from evo and tpc. i made a new thread so it wouldn't get lost in the other thread.

the tpc 3.4L kit seems to makes a lot more power under the curve. 3.6L evo kit wins out max power wise but still loses out on low range power.


EDIT plot shows stock HP now

 

The EVO graph for the 3.4 is in 3rd gear and the TPC is in 4th. Big difference is drivetrain loss.

 

in my experience, a 3rd gear run will net HIGHER hp #s than a 4th gear run. i've got numerous runs to prove it. 3rd and 4th gear runs done on MY car.

so with your observation the 4th gear TPC run makes even more power that the 3rd gear evo run. where does it say the TPC run was done in 4th gear? i can't find it anywhere.

 

i'd love to see that top chart with the stock on there as well for comparison. looks like the evo makes nothing on the bottom end till you get high in the rpm range.

 

You have just helped convince some people that dyno results are easily skewed. If it is true that your car showed more rwhp in 3rd gear than it did in 4th, then the dyno reported wrong. The more you move away from a 1:1 gear ratio on a dyno, the more power that is lost to the gears and therefore less power will get to the wheels. Remember, acceleration speed does not translate to horsepower.

Before I purchased the EVO system, I emailed TPC and they stated that their dyno was done in 4th gear.

Like I said before, drive both and see which one you like the best. Dyno's don't mean sh*t.

 

Actually any chassis dyno is pure bull****, you need a real engine dyno----motor out of the car---water brake, anything else is a joke, purely for the tuners and emissions testers, might as well use a 100$ g timer. Do you think Jack Rousch or Hendricks uses a chassis dyno on their NCC rides? But, that's another topic altogether.
I think a sc is a acceptable mod, and TPC also builds a pretty damn good one, not just evo. TPC also RACES which is key in the development of speed equipment, evo to my knowledge does not, also not sure you get the same quality install when evo doesn't actually do it, rather the guy who took the weekend course, TPC and Ruf do their own. I also think alot of porsche price gauging goes on as well, I saw a similar kit advertised for a ricemoblie for 3500$, by one of these sellers, common' they can't be that much different. Reliabilty is yet to be proven, as Kevin said, not alot of bottom end work has been done on these motors to handle the extra boost, that will change within the next 2 yrs I'm sure. The Ruf kit is probably the best and most reliable, just tooooo pricey.
I've been up in the air several times with my debit card in hand, just can't pull the trigger, too many unanswered(honestly) questions. I commend Kirby for his candor, I know Robyn can probably say alot more. but that's cool too, I know she's trying to sell a car and run a new bus. Off my soapbox, flame away!

 

it didn't report wrong, it just proved that 3rd gear is actually more efficient than 4th gear. it was done a dynapac which is reportedly more accurate than dynojets. same thing happened on the dynojet. 3rd gear reported higher than 4th.

you are right though. can't really compare the 2 runs because they are done in different gears. i have found a 10~15HP difference in 3rd and 4th gear runs. extrapolating this data the TPC should report 10~15HP even higher if done in third gear. maybe you are mistaken and the TPC run is done in 3rd gear.

if you think they mean **** why do you keep reporting that you modded SC reoprts XXXHP? why the hell would you care about the numbers then?

 

these dyno test have to be done in a consistent manner or else they are bull****. when it becomes consistent then it can be a reliable method of testing eliminating as many variables as possible.

dynapacs are much more acurate as they bolt up right to the hubs and use hydraulics rather than inertia to calculate the loads.

so here's another question, if the TPC kit produces more boost down low wouldn't that make that less reliable?

so TPC races with their SCs? i can't find it anywhere on their site. would you have a link? looks like they are racing in grand am so that means they are not using the SC.

 

i'll get to it in the morning.

 

I talked to one of their guys a while ago, the sc race car is a track car/DE toy, not really setup for class racing in grand am/scca but they do apparently race it in some local sanctionig deal/all out anything goes. I remember seeing stuff on their site about that this past spring.
Nice bumper BTW.

 

Ok, I don't have the time (or the knowledge) to write an essay in physics, but the fact that your dyno results showed more horsepower at the wheels when in 3rd gear compared to 4th gear, is proof that the dyno results were wrong.

The crank hp is always the same but when you transfer the power through a transmission, you lose some of that power in the form of heat and the energy necessary to move all componants connected to the crank. This is why you see a jump in wheel horsepower when you put a lighter flywheel on your car. The flywheel takes less energy to turn, and since energy cannot be destroyed, the unused portion continues travelling onward towards the wheels. The energy then has to turn the transmission gears. The bigger the gears, the more enegry is used to turn them and the more energy is transfered into heat. Only the energy that is not transfered on it's way to the wheels is measured by the dyno.

Gear size/weight, transmission oil thickness, friction, axle angle, etc, all absorb energy and thereofre reduce the amount of horsepower getting to the wheels. As a matter of fact, if you compared a dyno run on your car in 4th gear and 1st gear, there would be in excess of 75 hp lossed dropping down to 1st.

There are many sources you can research on this subject, so if you want a detailed scientific explaination, you can find it.

 

Thanks for sharing those two dyno charts, the overlay clearly displays a lot. The TPC give the 911's a FAR superior powerband!

...Not to mention that 434RWHP figure on the EVO represents a higher figure than ANY other kit has ever made (wasn't that the tweaked out one-off modded up kit anyway?)....more realistic figures are around ~410 rwhp on a 3.6's for EVO* (from what many others have posted*) ... The 393 RWHP figure of the TPC kit represents the lowest figure you could expect from their kit on a 3.6* More realistically you'd get over 400RWHP easily (bottom line, those posted charts are comparing the biased highest EVO run ever to a VERY low example/bad day for the TPC. ...not to mention the runs were done on different dyno's in different gears. All this said, it's STILL blatantly obvious which one has the superior powerband for just about ANY scenerio short of Vmax* (the TPC SC)

I don't know if you guys remember the video posted somewhere on here of the race between a highly modded Centrifugally supercharged E46 M3 with a stock 911 TT w/ X50. Those two cars are practically the same weight with that particular M3 making about 25-35 RWHP MORE than the TT he was racing....they were dead even in the race (even in the top end) becuase the TT's powerband was so FAT the torque kept catapulting it forward with every gear change compared to having to rev the beans out of the M3 to progressively get the power out of it. If two 911's are making anywhere close to the same peak RWHP but ones positive displacement/turbocharged...and the other is centrifugally SC'ed or a high output N/A type peaky powerband....its obvious which one will always be much faster, this is simple physics. IMO, if TPC had as many distributors as EVO (and hence kits out there), you'd be hearing of people on these forums bragging of 11-sec 1/4 mile runs and beating **GT2's** on the highway in their 996's all the time.

 

nice explanation of driveline transference but it doesn't explain jack about why you get more HP in one gear and less in another.

theory and practice are different animals. my practice showed your theory incorrect at least when it comes down to my porsche not some 5.0L car off the web.

 

You have to be joshing me? You REALLY don't get it? You have a set HP at the crank and you measure the hp loss to the wheels using one set of gears and then you do the same measurement using bigger, heaver gears and you think you will actually gain more power to the wheels? I guess you assume that Porsche has some secret way of transfering power to the wheels that no other car has?

Boy, I wish I had your dyno. I could dyno it in 1st gear and show some 700+ RWHP.

Please tell me you are joking.

 

haha, you think all gearboxes are built the same? now you have got to be joking. driveline transference can be different in every gear. even your plot shows it. it doesn't mean the loss is linear however. only thing your plot shows is that the 5.0L has a crappy 1st gear.