Awesome!

Yes you are correct, but what i said later on was why it may not be as high (the different launch speeds, and run times)

I think you missed my point. The point is a dyno's fans never simulate real air flow that is seen on the road. So gains we see on the dyno will be lower because of less air flow for the intercooler and radiator.
Not using fans on a dyno is like not using laces with your shoes.

My point was that if a 3" exhaust is ok for the common 2.0L stage 2 WRX, then the same can be said about the Mini making similar HP. HP= airflow. The only difference from the 2.0L to the 1.6L making the same power is low end TQ and the 1.6L is running more boost. At 200 engine HP both engine are flowing the same air.

Thank goodness, we agree!

Your right, with the Unichip we changed the boost, we changed the AFR, but on purpose and to levels we feel is safe. It does make for a nice dyno sheet, and a consistent one at that. There is no AFR or ECU tuning going on here with our Dyno results. Like we have said many times before, we do many runs to prove it makes HP. Are you saying our 7 runs averaged out to show a gain of 10HP don't count? How does this justify an independent dyno result being bad?? BTW, 90% of our results were done on an independent dyno. If you noticed at the bottom of the screen-shots for alot of our parts it says PDXtuning. That is not us.....

In this example the AFR's have nothing to do with someones dyno results, unless we start talking about ECU tuning stuff. The parts get bolted on, they make power. The only time AFR matters is if the intake system has some strange turbulence and throws it off and causes the AFR to be unsafe. Which we have proven our intake doesn't. Other than that, the exhausts and all other parts still run the same AFR (or so close its not worth mentioning). We have almost a hundred runs with the r56 showing this. The car runs the same 14.0-10.5AFR to redline with bolt ons.

If we use the dyno runs we did in the past, with an ambient of our average rise over ambient is anywhere from 10-40 degrees over ambient. You can't use this data without knowing inlet and outlet temp, along with pressure drop to determine how an IC works. You should be concerned with IC efficiency and pressure drop. We have shown this data on our site also. The Prototype was about a 2.8psi drop compared to the stock being 2psi. The final design was about 1.5psi. This is all when making about 180WHP or so. The IC efficency of the older prototype was 85%, which is really good! But we sacrificed a little of this for the new one, which is still above 82%.

I am not a 335 Expert, and i have no idea what size of tubing is used on them, but past examples of different turbo cars have always shown bigger is better, until sound becomes an issue.

 

Its all about boost. More boost= more air flow. Its kind of like when the muscle car guys go, how can that little 4-banger make as much HP as my Vette? There is no replacement for displacement. But in this case the replacement is boost.

But you are correct given the same RPM, boost, and 2 different displacments the smaller engine will be making less HP. I know there are a million other factors like timing, fuel, but keeping all things consistent, this airflow=HP works.

 

HP=Airflow??

I do not really think that you can prove that....

or you mean that a 600cc smart with 82hp has the same exhaust airflow with a 1,2L Nissan Micra that has the same output.
It is not like that...


Regarding the numbers, an ALTA CAI is advertised to give around 10whp

The ALTA catback is advertised to give around 10whp.

Since it is agreed that the overal performance is not accumulative(meaning that we do NOT count 10+10=20 whp from these two modifications), I take a factor of 40% less (I think it is fair enough). So, the overall gain should be around 12 whp from these two mods.
Our friend got 6-8 whp, meening and other 35% less.

Can the difference in dyno method/type justify this 35% loss, or the advertised numbers are a little bit higher...???

 

Thanks for clearing that up Jeff!

 

actually it is that simple and if you were to go back to your highschool physics teacher he'd smack you upside the head.
The 600cc smart is turbocharged, the 1200cc micra isn't, when you're pumping double the air into a cylinder half the size ... it kind of evens out doesn't it.

Something else no-one's seemed to mention/notice, Alta's "claims" show where on the dyno they make the gains in torque & hp, as opposed to simply peak power changes.
If you want to look at if the gains are really worthwhile, check out the change in area under the curve

 

.....it seems like we're arguing some fine points beyond the attention span of most consumers.....my view is that a GPS-based in car dyno using runs of say 40 to 110mph is probably the only practical way of drawing any conclusions on any given car....consumers can do that on their own ...as long as the wind and ambient temp remain the same, you have an accurate before and after comparison

 

Area under the curve is a great way to determine HP. I wish our computer had a button for that

Yes, we may be arguing some fine points, but the fine points are important for on lookers to understand how a dyno works, and or how HP changes with different conditions.

I agree a road test going from 40 to 110 is probably the best test. BUt not legal unless at a track. And to do all the testing at the track is not feasable, and not convenient. All we can do is continue to show everyone what we see on the dyno, and back that up with customers dyno graphs. We could use this customers graphs, but there were a few things that change the HP and TQ, like start RPM, run time and ending RPM. The scoope being removed is important on the intake, and many don't do this. Even octane makes a huge huge difference. If the customer is not putting premium fuel in his car all the time (which EVERYONE here should be doing) this could be an issue. I had a customer call and say he was using 87 in his car most of the time, and then put 1/4 tank of 91 in to see how it worked!! YIKES!!

I guess we should stop going on an on about this customers dyno results. I feel like we have made our points on how the results can vary. I hope that others can see our points on the questions and comments made by others, and use that to make their own decisions of what they are seeing.

 

I just ordered an Alta Cat Back Exhaust. I assumed that the exhaust would not provide 10HP at the wheels but would hope for 5HP. I came to this conclusion because most (99%) manufacturers use ideal conditions and give any benefit of the doubt to their product when stating HP. I do beleive alta produced the 10HP on their dyno (were they running 93octane) did they use a very large fan to reproduce driving conditions.

My bottom line is - I am just grateful they did something to prove ther HP numbers rather than just claim 25HP for exhaust/20 HP for intake/ 50 HP for a thing that goes into the intake tube that spins around in Tornado like fashion.

If I notice any difference other than visual I will be pleased. I would not be able to feel the difference between 5-10 hp anyway. Now once the PNP has been proven reliable an extra 20HP sounds good.

I have a question for anyone on this forum- How safe do you think the boost levels of the Alta ECU is for an owner who wants the motor to stay strong and not have issues for say 70kmi?

 

I placed an order through one of Alta's dealers. He was told it would ship last Friday. He was not notified and called today to get the tracking. He was informed the exhaust never shipped. Alta's response was they are on back order until late March. What a joke, I almost expected this from Alta. You only sell 10-15 products for the R56 and the exhaust is the most popular. I would call Alta and voice my concern but I feel it would be a total waist of time based on a few people I have spoken with. If one of their dealers does not get a explanation why should a customer.

I would not be this upset if I did not burn a day off of work and the dealer did not call to double check it was in stock before he ordered.

ALTA WILL BE OUT OF STOCK ON EXHAUST SYSTEMS ALL MONTH

 

___________________________________

...the factory has already determined that

 

My personal feeling is the higher the boost / power levels, the shorter the life span of the engine and compressors. But I don't think 2-4psi is going to make a huge impact assuming the tuning is done thoughtfully. Keep it around 18-19psi and you should be OK for 70k. Just don't expect it to last 200k.

 

My apologies to all that are waiting for the R56 exhaust system. We are making them as fast as we can. I will check with the production department to see if we can pull them off other projects to get these exhausts faster.

I'll keep ya all informed here.

JohnL

 

Wow! I can't imagine getting that upset over an aftermarket car part. It's on back order. so what! can you not still drive your car?

 

I'm just curious if you have some compulsion to give your opinion or if you have some real experience to base this on ?
Maximum boost levels have little to do with expected lifespan of a motor, assuming the motor's not knocking or the EGT's aren't too high, there's no reason to believe it would fail any sooner then a stock motor treated in the same fashion. The primary factors leading to a premature failure are things like infrequent oil changes, sustained high rpms/boost (eg. time on the track), stop & go traffic (eg. horrible regular rush-hour commutes), ...
Having all that extra power might encourage you to really thrash on the motor, but as long as you're staying within the proper range of the turbo, there's no inherent reason for it to fail prematurely due only to the higher psi.

 

Until people rack up 100k miles at higher boost levels on the R56 we won't know, but higher boost also means higher turbine RPM. A turbo throwing metal shavings through the intercooler and engine would be a bad day.

 

almost all the turbo failures I see on a daily basis are failures at the oil seals, the smoke pouring out the tailpipe is usually enough advance notice for most people. It starts out with a small amount of smoke on startup, at that point hopefully you get it checked out. The turbines really don't throw metal shavings unless some foreign objects get in there. Sometimes the turbine shaft will sieze up (oil starvation) or even snap, but they still don't fire out shrapnel. The closest I've come across was one that spit the exhaust wheel out leaving it sitting atop the pre-cat. The R56 has a nice post shutdown coolant pump to help prevent coking in the turbo as well.
I think worst case you may have to replace the turbo at some point unless there's some manufacturing defect or serious design flaw.