Sneak Peek of New Stainless Steel Headers

[mb911]

impressive numbers

[zzwhm]

It's my 3.2 that got 220.92 at the rear wheels mentioned above. I'm sort of a dyno nut and out of curiosity have tested a few exhaust/muffler variations.

The dyno runs above were when I wanted to compare 1/1/2 SSI to 1 5/8 headers. The catalyst was that I noticed guys running larger diameter headers on their 3.0s and 3.2s seemed to have more torque and could pull me on the straights. I went into this as a firm believer in SSI and wanted some evidence that larger headers would make a difference. I was really surprised when the dyno results showed a substantial gain in torque and ~20 hp difference above 6k where the SSI fell off a cliff.

BTW, for grins I also tested a drilled airbox versus stock. Only 1 hp difference, which is statistically noise, but free.

Bill

[Steve W]

Jim and Bill, nice work!

Bill, looks like you found the cause of your lower HP, your car should be very competitive now. How did your AFRs look afterwards, were they within a safe range?

[zzwhm]

Steve, here's the results with AFRs. Pretty sure I had the o2 sensor attached for the SSI runs. Bill

[911st]

If it is a WOT run the O2 should not effect the AFR's.

If the AFR's are not normalized I suspect the result of compairing one system to another is not very valid.

If I read this righ the old system was to lean at 14/1 at HP peak and headers were at 12.5/1. Neither is ideal but I suspect that 12.5/1 will make more power every time.

It seems odd that the motor would run richer after the change unless the chip, fuel pressure, or ECU fuel quality switch were changed.

I certainly am not an expert on this.

[mb911]

Originally Posted by 911st

If it is a WOT run the O2 should not effect the AFR's.

If the AFR's are not normalized I suspect the result of compairing one system to another is not very valid.

If I read this righ the old system was to lean at 14/1 at HP peak and headers were at 12.5/1. Neither is ideal but I suspect that 12.5/1 will make more power every time.

It seems odd that the motor would run richer after the change unless the chip, fuel pressure, or ECU fuel quality switch were changed.

I certainly am not an expert on this.

I would agree with your statement as well and a note typically back to back comparisons are skewed simply because the ECU and timing etc is not optimized for the additional/flow/restriction what ever it may be.

[zzwhm]

The chip, fuel pressure and ECU stayed the same. The ECU fuel quality switch was set to richest setting.

I'm definately not an expert either, just hunting for any improvement I can get. Hard running E Class in a G50 Carrera against the Euro SCs.
Bill

[911st]

My guess is the Fuel Quality Switch was cranked up with the new header install. ???

Any decent 1 5/8's or 1 3/4's header should out preform a 1.5" SSI to about 10hp assunming a same muffler.

A better comparison would be the Euro George 1 5/8 or 1 3/4" headers w Phase 9's or
Flowmaster. I believe that seems to be the standard unless one wants to step up to some very expensive stepped headers.

Not sure how much scavenging that can be done with a stock low overlap cam (tube volume and length). I think it is more about increasing efficiency / reducing back pressure.

Still, love the long tube design, collectors, and expantion chamber. Nice work.

Again, I am not an expert just what I belive.

[JB]

When we did the dyno test on Bills car, the only difference other than the headers was the oxygen sensor was unplugged as there was no bung on the new headers.

And ST, just to clarify, these are "stepped" headers (1 5/8" to 1 3/4").

The initial development was done back to back with ER's and showed we had at least a 10HP gain on a 9.8:1 Euro SC. I agree we need to do another back to back test with the production units and that will be soon. I will post the results when I get them.

Thanks!
Jim

Btw, Another customer of mine just dyno'd his 1987 3.2 "E" class club racer with 1 5/8" ER's and it made 208 at the rear wheels.

[911st]

Back to backs are always the best but not often easy to do. Also, dynos do vary.

I remove my O2 when I dyno also. No issue in doing so as the O2 is out of the picture at WOT.

With a chip, stock headers & muffler, and cat bypas I dyno at 215 to 217 with 130k miles on the clock. My friend dynoed a bit higher with the same set up but a Bursch 1/1 sport muffler.

However, I suspect you can not change the chip. Still, I believe a chip can be gotten close to by playing with the AFM, Fuel Quality switch. Just can not legally do much with the timing (crank sensor & temp sensor inputs).

Again, the standard seems to be a properly sized Euro George headers w Phase 9's. That is the best system to test against.

I think the following info is very insightful.

Originally Posted by Steve W

I've compiled a spreadsheet of expected power output values based on a internally stock 3.2 Carrera motor based on dyno tuning data that I've accumulated from many cars over the years. The output values are given in engine flywheel hp assuming a Superflow engine dyno such as at Jerry Woods. You results may vary, based on the flow quality of your muffler, but for a healthy 3.2 motor, I estimate these values to be accurate to within 2-3 hp of each other.

[zzwhm]

If we ignore variation in dynos and figure 15% loss, the stepped headers and stock chip got ~259 at the crank which kinda slots in between Steves numbers at the top end. I sure wish PCA would let us use chips to tune the ECU cars.

[911st]

I think you get that Steve's numbers seem to be calibrated or adjusted to kind of compare to factory crank numbers (he references JW's crank dyno).

The dyno I use puts me at 215 to 217 at the rear wheels. At 15% that would be 253 hp fwhp compared to SW's 236hp from the table for basically the same set up. Thus, I would not compare wheel dyno numbers directly to his.

What I find usefull are the delta's between set ups.

For example, SSI's are really a good 1.5" header and when combined with Phase 9's makes about 10 hp less than larger 1 5/8's or 1 3/4's headers and open exhaust. It takes the best headers money can buy and race fuel with an optimized chip to make another 8-11 hp.

Not being able to use a chip dose not stop one from manipulating the AFR's. The ignition is the challenge.

I have wondered how I would tune my car if I could not chip. Playing with AFm calibrations, the fuel quality switch, tuning the exhaust to fit the chip (cross over), and playing with the cam timing would be my starting points. If you are limited to 6500rpm, maybe retimming the cam to fill in the early part of the TQ curve might yeald some improvement.

The ignition side is the challenge. If they allow playing with the temp sensor inputs one could delay the ignition from being pulled back with increases in temp. Or one could "blue print" the flywheel or fw sensor.

If I were racing I would put SW on retainer and look into what stock chip are the best (club sport?) and how to manipulate the adjustments that can be made. The Miata guys swap ECU's on the dyno to see what works best. The successful ones even run lower viscosity oil for a small HP gain.

Looking at the dyno curve posted here showing the AFRs', I suspect that the variance between the two setups might not be as much if the fuel quality switch had been used to correct the lean condition of the before system.

Just my thoughts.

[Steve W]

Thanks for posting chart. The very lean afr reading with the SSI has never looked right. With the stock chip, it should actually go very rich at the upper rpms so I suspect it is not accurate - possibly a vacuum leak at the wideband lambda sensor of the dyno at the time, or possibly even an exhaust leak. The fact that with the new headers displays richer seems to confirm it because a freer exhaust will always dyno leaner and require more fuel, the opposite of what is showing here.

The dyno numbers that are referenced on the hp chart posted by 911st are normalized to a Superflow engine type dyno, which should be closer to the factory numbers. I have found and suspect over the years that the loss at the wheels on a 911 for a Dynojet SAE corrected is closer to 11-12%, not 15. I have a set of hundreds, maybe a thousand Dynojet runs accumulated from a probably a few hundred different Porsches, from 3.2 to present, undergoing various stages of modification that I'm using as a basis. For example, a 2007-2008 GT3 is rated at 415 HP, while my completely stock GT3 dynoed 371 at the wheels on Vision's Dynojet, in line with what others have gotten. I don't think the factory really underrates their motors, so using a 11% loss ( divide by 0.89 ) comes to 417 HP. Therefore a motor that dynos 221 at the rear wheels is actually closer to 248-251 at the flywheel. Chip tuning Bill's car with more ignition timing for 91-93 octane pump gas should bring about another 8-10 hp.

[911st]

Steve,

Hope you do not mind my reposting but you are a great source of very good info.

Here I go again.

I thought the following might be helpfull to know if a chip can not be used per class rules.

Originally Posted by Steve W

The data on the chart is based on an 87-89 ECU unit. Although the 87-89s are supposed to put out 10 more hp than the 84-86s because of the programming, I have not seen an appreciable difference on the dyno between the two. At cold ambient temps, the 87-89 cars may put out a bit more hp, but at normal to warm temps, it seems as if the later programming puts out less power because it is more aggressive at trimming back overall ignition timing as the ambient temps rise. The later programming does put out a bit more low and mid end throttle response than the earlier cars, which give the impression that they are more powerful though. In either case, the power gains from chipping are the same no matter which year the car is. The chips are already tuned and tested assuming 91 octane with 10% ethanol, so that is not an issue. Also, as I mentioned, the Motronic programming is designed to trim back overall ignition timing irelative to the ambient intake air temps, so even if you are in 100+ degree heat, the programming compensates and keep you in a safe range...

[zzwhm]

911st -
The cam timing is advanced and as you noted, it fills in the bottom a bit. You're right that some stock chips are better than others and Steve can advise on which ones are best. But I'm not sure that a Club Sport chip would be legal for my car since it alters the RPM limit.

One other benefit of this header system is that it's light compared to ER.

Bill

[cdrik915]

Splendid exhaust !!!!

Hight quality welded , equal lenght .....i just would suggest the same headers but with a very simple system for keeping the heat system.

And a muffler more adapted to street use.

I consider the price as correct , comparing performances , quality , furnitures .

[ninesixfour]

Originally Posted by RarlyL8

The most tweaked stock CIS 3.0L engine I've come across put out 191HP at the wheels. To squeeze 210 at the wheels on CIS has got to be near maximum efficiency. Very impressive.

I agree. How is it possible while staying within the CR rules?

[Mahler9th]

Very nice looking. So $2400 for about 10 bhp? Have they been compared to George's European headers? My engine started out with those, and I think you can set a set of the larger ones for about $7-800.

Have they been compared to the Mark Robles headers sold by S Car Go? I now have a set of those, and they are very, very nice, and have been documented in terms of power. I have the original version... I think S Car Go sells a less expensive version as well. So how would you summarize the benefits over George's and the S Car Go units? Modularity and perhaps weight are two advantages over the European headers.

[JB]

Well said Mike. The 10+ HP on a Late Euro SC is compared to European Racing Headers. Modularity and lite weight are also a plus. Stainless vs mild steel is a plus.

Ninesixfour, it is possible if your motor is up to Euro SC stock spec and using our header system. My email & phone # are on my website if you want to discuss.

Best Regards to all,

Jim

By the way, we will be PCA Club racing this weekend at the new High Plains Raceway just east of Denver if anyone is in that area and wants to drop by to see how we're doing.

[JB]

Update: We have completed testing and development on our street and track muffler system and should have production units by the end of the year. (Sorry, there is no heat option at this time. )

Our new muffler design works only with our headers and utilizes two stage mufflers for the street or single stage mufflers for the track. The muffler canisters are very high quality 304 stainless units made by Burns Stainless. The two into one configuration produces a higher pitch tone with more power (pulse scavenging) and reduced sound levels than a straight through design. Measured sound levels on open track are 86dB for our street configuration and less than 89 dB for the track (measured at 100'). The track system is configured with V-bands to quickly change from muffler to tuned megaphones for tracks that have noise restrictions.

The prototype street system with two stage mufflers is shown below:






By the way, another E-class track record utilizing our headers was set at High Plains Raceway at the PCA race in August. 2:01.8