[Neanderthal Racing]

Originally Posted by JJ18Sniper

bruce, are you going to incorporate this into your setup?

eventually, providing these cams pan out. i know some people will disagree but cams are less of a priority when you are using a huge turbo to make power. if it was a n/a motor i'd feel differently.

i had the same problem as everyone else is when i was doing the valves and springs and i had the chance to get them; no one had any experience with these dpr cams. they were way too new at the time, although i believe a one or two people on nasioc has had some experience with them by now. i had the aditional problem that i'm using phil's base map and a lot of head work (full p&p) and other than stock cams would have thrown off the tune. phil discouraged major head work for that reason.

i do plan to attend to the heads the next time the motor is out; maybe next year.

[Davenow]

cams are MORE essential on a turbo car. I cant even fathom how you can say that.

[Neanderthal Racing]

Originally Posted by Davenow

cams are MORE essential on a turbo car. I cant even fathom how you can say that.

sorry, but youre just going to have to fathom it.

[Davenow]

Originally Posted by BruceChapman

sorry, but youre just going to have to fathom it.

Seriously though, the ask any engine builder, who does turbo motors, if cams are not INCREDIBLY vital, even moreso than on a N/A motor.

As you know, the cams are what determine how much air flows in and out of the cyl, for how long, and when. When you are dealing with a highly pressurized air charge, the effect they have is multiplied many times over.

A prime example is the wrx that made 300whp with a vf34 at 12PSI. For reference, it would normally take 21+psi to hit 300whp with that turbo, if you could even get there. That car previously made 270whp@19.5PSI. They dropped 7 1/2lbs of boost, and gained 30whp, and the torque curve was pretty much a big long flat line from about 2500 to 6500

Where a bigger turbo just shoves the peak of the curve up, it also typically narrows the curve, A well matched set of cams will push the peak up, but also push and fatten the entire curve. Peak gains may only be 15-20whp, but gains at 3000 and redline may be 40-50whp. The car with the lower peak number, and way fatter curve will be decidedly faster.

[Neanderthal Racing]

Originally Posted by Davenow

Seriously though, the ask any engine builder, who does turbo motors, if cams are not INCREDIBLY vital, even moreso than on a N/A motor.

As you know, the cams are what determine how much air flows in and out of the cyl, for how long, and when. When you are dealing with a highly pressurized air charge, the effect they have is multiplied many times over.

A prime example is the wrx that made 300whp with a vf34 at 12PSI. For reference, it would normally take 21+psi to hit 300whp with that turbo, if you could even get there. That car previously made 270whp@19.5PSI. They dropped 7 1/2lbs of boost, and gained 30whp, and the torque curve was pretty much a big long flat line from about 2500 to 6500

Where a bigger turbo just shoves the peak of the curve up, it also typically narrows the curve, A well matched set of cams will push the peak up, but also push and fatten the entire curve. Peak gains may only be 15-20whp, but gains at 3000 and redline may be 40-50whp. The car with the lower peak number, and way fatter curve will be decidedly faster.

youre working way too hard to make yourself look smart because my comment didn't require a technical answer. i'll even stipulate youre a genius so you don't have to try so hard.

by this spring i'll have between 550 and 600 whp. do you really think i give a rat's ass if i throw a cam in there, dave? let me answer my own question. no.

[Davenow]

Originally Posted by BruceChapman

youre working way too hard to make yourself look smart because my comment didn't require a technical answer. i'll even stipulate youre a genius so you don't have to try so hard.

by this spring i'll have between 550 and 600 whp. do you really think i give a rat's ass if i throw a cam in there, dave? let me answer my own question. no.

Not trying to sound smart, just trying to give as detailled of an answer, because so many ppl here will tear you apart if you miss one minute detail.
It also prevents 10 replies asking 50 things you didnt detail...

How about someone that builds a 500-550whp car WITH cams, then smokes you because you have a powerband 1500rpm wide??
Because I have seen that happen a dozen times.

Case in point, RedRockets STI that made 371whp and ran high 12's because it made crap below 4700rpm and was gutless anywhere other than a 1000rpm wide powerband. 371whp on a good setup is 11's. His car, driven well ran high 12's. Its all about area under the curve.

[Neanderthal Racing]

Originally Posted by Davenow

Not trying to sound smart, just trying to give as detailled of an answer, because so many ppl here will tear you apart if you miss one minute detail.
It also prevents 10 replies asking 50 things you didnt detail...

How about someone that builds a 500-550whp car WITH cams, then smokes you because you have a powerband 1500rpm wide??
Because I have seen that happen a dozen times.

it'll break make heart and completely shake my confidence, dave. before you know it, i'm so depressed i start hitting prozak and viagra ****tails like rush limbah popping vicoden. on christmas morning i finally commit suicide by police in a hail of gunfire. not pretty.

[Tortfeasor STi]

Cams can make a big difference in how an engine flows air. However, when dealing with forced induction you have to be very carefull with duration and overlap or the result will be blowing the intake charge directly into the exhaust without making power. I would not buy a cam for any car I owned without knowing exactly how it affects idle characteristics, it's long term effect on valve train life and whether the tuner I am using has experience tuning for the change in cams.

Also, what a camshaft does is change the valve events to maximize airflow into the cylenders. However, they are not the be all and end all in airflow efficiency. Cylender head design and intake manifold design have huge effects on both peak power and average power over the course of the rpm band. A cam shaft should be optimized to your cylender heads, manifold and means of forced induction. Engine building is a package deal and you can realy mess things up by simply bolting on random products, cam shafts in particular.

Now, when using a turbo charger you have to be doubly sensitive to valve events because it is the cam shaft controlled exhaust pulses from these valve events that turn the compresor wheel. Now, when increasing the efficiency of an engine by use of camshafts, you can make the same amount of power with less boost because there is less back pressure in the intake tract because the engine is flowing more air. This does not mean that the stock snail will magically make more power. Every turbo has an efficiency range measured in airflow. This is why you need a huge snail to power a v-8 engine and a small snail to power a 4 banger. So, when you increase engine efficiency it is possible for peak psi to decrease while peak power increases. And if you exceed the airflow capacities of the stock sized turbo you will not be helping yourself produce more power.

Bruce's original post saying he would wait to see if the cams pan out sounds like words of wisdom here. Especially considering how sensitive the STi is to random modifications. It is a lot easier, and usually more cost efficient on a $/hp standpoint, to upgrade your means of forced induction than tear down a motor. Especially if you consider driveabillity to be a priority. the most tweaked out race motors make huge hp but would not be able to idle at a stop light. So, if we can get more information from the company and some people with practical experience caming up a stock style EJ25 engine, then we will have some valuable information from which to judge whether cam shafts are a good modification for our engines. But until there is a lot more development on these engines I for one will be sticking to more conventional modifications.

[Neanderthal Racing]

dude, that was an awsome presentation.

[sachin]

When I asked Quirt Crawford he told me cams are more important in terms of making power an NA application than with a turbo application...with a turbo application all they really do is move the powerband around. Not exactly a technical post, but *shrug*

It's worth noting that a lot of NASIOC guys have seen some nice gains from DPR cams.

[STI*FEVER]

Gadiel's 719 HP STI (worlds fastest USDM STI) rocks STOCK cams
seems like he knows what he's doing.

[evilSTi7]

Originally Posted by BruceChapman

it'll break make heart and completely shake my confidence, dave. before you know it, i'm so depressed i start hitting prozak and viagra ****tails like rush limbah popping vicoden. on christmas morning i finally commit suicide by police in a hail of gunfire. not pretty.

if so, i call your sti, and the harley.

[TTTT]

Originally Posted by BruceChapman

it'll break make heart and completely shake my confidence, dave. before you know it, i'm so depressed i start hitting prozak and viagra ****tails like rush limbah popping vicoden. on christmas morning i finally commit suicide by police in a hail of gunfire. not pretty.

If you kill yourself, can I have your car Bruce?

btw..you never answered my pm a while back when i posted my v3 pics (sniffle)

[Neanderthal Racing]

Originally Posted by TTTT

If you kill yourself, can I have your car Bruce?

sorry, man, but the car's going down with me like bonnie and clyde, tttt. all i have to do now is to talk hilary into going down in a hail of gunfire with me (youre more likely to get a shot at the girlfriend than the car)

Originally Posted by tttt

btw..you never answered my pm a while back when i posted my v3 pics (sniffle)

hanky?
(the pics were great!)

[PhantomLord71]

I might be a little late to the party for this topic but I have to respond to this and put my 2 cents in.
I own a 04' STi and love it to death. I have the Cobb downpipe, RS*R catback and the Cobb AccessPort running Stage 2/93 Octane. My car feels great and has run a best of 12.98@102. My friend, on the other hand has the dreaded EVO - the car that does everything better than the STi. His EVO has the Busher Racing turboback, Dynaflash reflash on the ECU, and a set of 270 HKS cams. Just suffice it to say that he totally kicks my a** everytime at the drags. That little 2 liter engine in the EVO with the turboback, reflash, and the CAMS puts my 2.5 to shame.
I am an old school hot rodder that has built stroker small block chevy's for a good portion of my life. You name it, I've most probably either built it or helped someone else build it. I know that cams make a huge difference with forced induction cars, I've seen it happen many time from swapping cams in blown small blocks. The cam is the heartbeat of the engine and swapping the stock cam for one that can fill the cylinder quicker and expell the exhaust gases more efficently WILL increase the power of the engine and greatly effect how the engine feels under the turbos/superchargers curve. My buddies EVO is a prime example that the new turbo imports react just like the old supercharged American V-8's I fooled with in the past. Cams make a difference, bottom line.
Someone mentioned the 700+ hp STi. I hate to tell them that there are EVO's putting 800+ hp to the wheels and running 9 second 1/4 miles. IMO, as long as the Subaru community keeps being narrow minded like with this cam issue - the EVO will continue to dominate the STi like it did at the latest EVO vs. STi shootout. I was simply humiliated to own my STi as I sat down at my friends house with the EVO and watched STi after STi get beat by the EVO. The 700 horse guy was there and he was the only saving grace for the STi that I saw.
Also, what good is having 400 or 500 hp if it's a totall slug below the turbo's curve. Do people realize that it's not the peak hp, but how fat the curve is. My friends EVO puts down 335 hp to the wheels and the hp and torque curve on his dyno sheet is amazing. By 2700 rpm, his car is starting to make power and it keeps increasing all the way to redline.
When I get the money a set of Cosworth heads and Stage 2 DPR cams are going on my car along with a FP red, APS front mount, bigger injectors/fuel pump, tumbler delete valves, and a full custom tune by Cobb in Utah. I'm sick of Evo's kicking my a**, time to do something about it and I'm not talking about just putting on a bigger turbo.