FWIW, the person who did the testing posted that the A/F logs were off due to an exhaust leak. In any case, those jagged lines don't look good - seem indicative of a problem.

 

they only had one of the best aem tuners tuning the car like that means anything.

 

That doesn't mean diddley squat if something has changed with the car during the 5 months lapse between the two dyno runs. A difference of 100whp between two similar sets of cams? Think about it...

 

I would say depends on the cars purpose if its a daily driver I would say the 264/264 would be best but if your on the track all the time and the car is just for playing not every day driving then I would recomend something more aggressive like 272/272 or the works setup.

 

Why would spool up be 100 rpm later with the 264 intake when compared to the 272? I thought the 264 would spool up quicker but fall off sooner. Is the quicker spool up with the 264/264 related more to the exhaust cam than it is the intake?

 

The 264/272 set will spool slightly later because it has a few degrees less of valve overlap, which in comparison to the straight 272 set, will give a bit less exhaust gas pressure at the same rpm.

 

I have had the WORKS 269ers in for over a month now. Streetability is exactly the same as stock besides a different exhaust note. I wouldn't consider the 269's as a track only cam. After a week I didn't even notice them.
The past weekend I put in about 200 miles of track time. My straight away top speed easily increased by 5mph. A tough thing to do as after 100mph it always has seemed to give up. My track times stayed the same but I was battling bad tire and brake problems. Considering the problems I was having and still running the same times as before the cams they are indeed worthwhile. I also used their valve springs and retainers for safe measure.
I love them so far. Install them, toss in the flash tune and never worry again. Just concentrate on the next corner.

 

Ted, you keep spewing assumptions without dealing with the facts- the chart i posted was uncorrected and without any smoothing. That is why it is jaggy.

I clearly stated this fact and also told you that the normal sae or standard charts with smoothing on looked much nicer. They were also within 10whp of the same numbers. I can post those up too but I will wait till I dyno the hks again this week to verify if the power came back.

You are also failing to consider that between the bjch stage 5++ head, bjch intake manifold and the 52 lb/minute gt30 on the car, it is possible we just outflowed the design of the pipers.

So far, all I can say is that I have observed that I had to add a lot of fuel when going back to the hks 272's so they appear to flow a lot more air uptop than the pipers.

You need to have all the info before you draw conclusions. That is why we are going to the trouble to redyno the HKS before we start saying anything.

Just labling a test "compromised" because you don't like the results doesn't help anyone. Wait till the second dyno and get your info complete before you start stating opinion as fact.

After the hks are dyno'd again, I will post charts with smoothing on/off and any other info relevant like timing afr etc from the aem ems logs.

 

The only thing I assumed was the A/F readings were accurate, and as you later indicated, they were not. That was the basis for my preliminary conclusion.

I have a difficult time believing the Pipers could pose a limitation in flow potential, simply because they appear have more lobe area than an HKS 264 set, and it is difficult to see a difference of 100whp between HKS sets. Although, the fact that you had to add more fuel to the 272 set indicates one or more of several possibilities.

Are the lobe profiles 100whp different? I could be wrong, but...

 

Well I am trying these soon, Pipers 11.5mm 10.8mm. maybe a little more lift @1mm and a longer duration inlet cam for good measure

 

you guys might want to read this

http://www.lancerregister.com/showth...s&pagenumber=1

 

No your right. The HKS cams spec wise have the lowest flow capacity of all the cams. Im not sure why the tests came out like that but the pipers specially with they were the 272 with 12mm lift would outflow the HKS cams terribly. There has to be somthing else involved that is causing these results. I have a buddy that owns a company that will be doing test results on every cam to come to conclusions. Hopefully this will happen soon!

Chris

 

http://www.socalevo.net/forums/viewt...?p=64933#64933

 

Looks like the Pipers were not dialed in correctly.

 

Interesting stuff. I wonder what the results would have been with a bigger set Pipers, though. I think GT-40's car may be considerably over built for the cams he tried out, or the "combo" Piper set-up may be poorly matched. Of course the Pipers may just not measure up, too. There is no denying the outcome, though.

My car should be going back together before too long, and it will have a set of Piper Rally cams (matched 11.5 lift & 265 duration) with a BJ's stage 5++ head. I'm planning on switching back to the stock airbox (to match the Vishnu Stage 1+ set-up - except for the ported head..) and will doing my initial testing with either the stock turbo or a stock turbo with a 10.5 hotside.

I know a fully ported head with oversize valves is an odd match for a stock turbo in a largely stock car, but I'm upgrading from the inside out; I'd rather get all the internal stuff out of the way first. I was originally planning a turbo upgrade at the same time, but it looks like that will wait a bit.