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CLASH OF THE TITANS
BROUGHT TO YOU BY SP ENGINEERING AND TO4R.COM
written by ken henderson

Its not that we don't care about the sound. Its not that we don't care about the fury. We do. But, the thing we at TO4R.com care about the most is making rear wheel horsepower. If it sounds good and looks even better, well.....that's just frosting on the cake. So, we decided to gather the leading products of four aftermarket powerhouses, HKS, GReddy, VeilSide and Blitz, to see which one would prevail in this clash of industry titans.

Let's get this out of the way right up front. We were dealing with private owners of the exhausts that were tested and not official HKS, GReddy, VeilSide or Blitz representatives. Its kind of a secret, but we'll let you in on it. Some aftermarket manufacturers assiduously avoid shootouts of any type. Nothing puts the bottom-line under pressure like a bad performance in a widely publicized shootout. Its much easier to explain away why you were missing in action than to explain why a competing exhaust, possibly cheaper, made 15, 20 or even 30 whp, and more torque to boot, than the exhaust you've been touting as all-conquering. Of the four invited, three showed up ready to do battle. More on that in a minute.

As many of you know, there have been numerous subject-specific threads and hijacked threads on the Supraforums, and other MKIV-based forums, regarding the "best" exhaust on the market. Surprisingly, from what I've observed, most of these discussions revolve around the sound quality, decibel level and the aesthetic appeal of the particular exhausts being discussed, rather than the ultimate power producing potential of the products in question. As noted, we like the power, and we'll do most anything, within reason of course, to get it.....and keep it.

Appetite whetted yet? Read on, and try not to skip ahead to the results, although we'll understand if you do. There's a lot going on here and some against-the-grain stuff that you'll find surprising. Enjoy.

the exhausts:
The participants that showed up to see who would be the last “man” standing were the early favorite, the VeilSide titanium, the long-time champ, the HKS titanium and the venerable and always competitive GReddy Power Extreme. The Blitz Nur Spec participant was a no-show for reasons unknown as of this writing. Hopefully, we can test this exhaust in another contest some time in the future.

The VeilSide is a slim (90mm) light weight (10 lbs) super fast contender going up against a pencil-straight 102 mm knock-out artist, the HKS titanium, with the winner taking on the 94mm GReddy PE; that is, of course, if the GReddy still wants a piece of the winner of the first-round action. We would have preferred to test the 94mm GReddy Evo, as did Turbo magazine in its June 2003 issue, because its a bit straighter and four pounds lighter than the 38 lb., PE, but none were available. Because many Supra owners roll with the GReddy PE, we felt there was still value in testing it for our customers (after all, a few years ago, I personally made 690.2 whp, SAE net, with HKS 264 cams at 1.75 bar with the PE).

the car:
As can be seen above, the car used for this test was the electric-blue custom wide body Supra of TO4R.com member Bill Robards. Those of you unfamiliar with this car can click on "Bill Robards" under "members" and read all about this amazing vehicle. For our purposes here, suffice it to say the car has all the goods, HKS GT2835 turbos, GReddy three-row front mount intercooler, HKS 264 cams, intake and exhaust, an HKS triple-plate clutch, an HKS EVC-Pro boost controller and an ACPT carbon fiber drive shaft.

Bill purchased this car in March 2003 and the car had not been on the dyno for about three years (699 whp at 2.05 bar) and, before he decides what power upgrades, if any, he wants to make, he had SP Engineering add a second fuel pump and carry out some ROM tuning of the ECU. This slight freshening resulted in 700.2 whp at somewhere between 1.8 and 1.85 bar (boost could not be held over 1.8) the day before our exhaust testing took place on May 23, 2003.

the process:
In order to ensure reliable and repeatable results, all things being equal, care was taken to remove as many variables as possible from the testing regimen. We agreed in advance to three dyno runs per exhaust (for a total of nine runs), no cool down period between dyno runs involving the same exhaust and at least one hour between the third run of a given exhaust and the first run of the next exhaust (this turned out to be 1 hour and 4 minutes between the HKS and the VeilSide and 1 hour and 9 minutes between the VeilSide and the PE). All runs were at 1.7 bar, SAE net, using Unocal pump 100-octane fuel. With the exhausts being tested on the same day, on the same dyno, using the same car and fuel with no tuning, we were confident we had done all that was reasonably possible to ensure reliable results. Because summer heat arrived this week without warning in southern California, there was some initial concern we would see significant variances in ambient air temperatures, but the day of the testing (5/23/03) was significantly more temperate than the day before.

the results:
With the HKS titanium already on Bill's car, it was logical to start with this exhaust. So, at 12:42 pm, the first run of the day went off without a hitch, as did all the others, resulting in 694 whp (693.9 actually) and 569.3 lb-ft (click here to see dyno sheet #1). The next two runs occurred at 12:45 and 12:48 pm, respectively, both resulting in 685 whp, a slight increase in torque on the second run (570.1 lb-ft) and a fairly significant 12-13 lb-ft decrease in torque on the third run (relative to the first two runs).

Up next was the HKS' chief challenger, the VeilSide 100% titanium Teardrop exhaust. Being the personal owner of this exhaust, and having had great success with it, I, and other TO4R.com members employing the same exhaust, Steve Wilson and Bill Robards in particular, all thought going in the VeilSide would be a strong contender for the Ultimate Street Exhaust Challenge, and it was......just not enough to topple the HKS titanium from its championship perch. On the dyno, the VeilSide snorted, gathered itself and produced 669.6, 667.8 and 663.3 whp at 1:47, 1:49 and 1:52 pm, respectively (click here to see dyno sheet #2). Good numbers all....just 22-24 whp less than the HKS titanium and down 12-14 lb-ft as well. Curiously, like the HKS, the VeilSide produced its highest torque rating on its second dyno run, although by a significant 12 lb-ft over the first dyno run. I'm not sure what caused this situation, other than maybe the HKS triple-plate clutch getting more heat in it during the second run and holding the torque better the second time around.

Forgive the GReddy Power Extreme if it feels a bit neglected. I also own this exhaust, having previously abandoned it for my new flame, the VeilSide titanium. I mean, what's a guy to do when a slinky, super hot, great looking, sexy piece of equipment outperforms your old standby by 30 whp and 10.5 lb-ft at the same boost level (for those of you that don't know this story, go to "members", click on "Ken Henderson" and read all about it)? None of us thought the GReddy would prevail but, as noted earlier, there are a lot of these exhausts in the Supra community and it has a strong, loyal following. So, at 3:01, 3:03 and 3:05 pm, respectively, we paid homage to the power producing potential of one of the community's most popular exhausts (plus, its legal here in California, a real big thing, trust me). And, the PE didn't let us down, generating 641 (640.9 actually), 637.6 and 639 whp while, at the same time, producing 524.7, 522.8 and 523.4 lb-ft at the standard boost level (click here to see dyno sheet #3). The PE was the only exhaust to pick up a bit of power and torque between the second and third dyno runs. Some would say testing an exhaust that's been replaced (?) by the GReddy Evo is a bit unfair and they have a point. When we do this again, we here at TO4R.com hope we'll have one available to test, along with the Blitz Nur Spec and any other maximum power exhaust claiming the ability to unseat the current and, some say, future champion, the HKS titanium.

Turbo, Sport Compact Car, Automobile and European Car magazines, among others, have all published articles suggesting larger diameter exhausts and, to a lesser degree, larger diameter throttle bodies have the unintended consequence of softening up the bottom end response, power and torque, only for the "softness" to be made up for by a stronger mid-range and an absolutely outrageous top end. The testing conducted by TO4R.com and SP Engineering put the lie to this conventional wisdom. Dyno sheets #4 (click here) and #5 (click here) overlay the maximum power and maximum torque numbers for the three exhausts tested (the torque numbers are picked up from the highest horsepower run so this is slightly inaccurate, but makes the point nevertheless). The 102 mm HKS titanium out powers, out torques and OUT SPOOLS the competition. To make the point even more dramatically, dyno sheet #6 (click here) shows Bill Robards' latest dyno run at 700.2 (2835s, 264 cams, HKS titanium) the 826 whp run of the SPE/TRD wide body Supra on the June 2003 cover of Turbo magazine (2835s, 272 cams, VeilSide intake with 100 mm throttle body, HKS titanium), my old 789.1 whp dyno sheet (modified GReddy TDO6s, 272 cams, VeilSide titanium) and Steve Wilson's 632.7 whp (HKS TO4R, 264 cams, VeilSide titanium, 3.73:1 ring and pinion). Removing Steve's car from consideration as a result of the 3.73:1 rear end (all the others are six-speeds with the stock 3.13s), the car with the biggest cams, the greatest exhaust internal diameter and the largest intake is also the fastest spooling and makes the most power in this comparison. Those wanting even more spool than the HKS titanium can provide might want to consider the 3.73:1 combination as it clearly makes a difference in how soon you can put the power to the ground.

With the intake air temperatures ranging from 77.9 F., (HKS), to 80.3 F., (VeilSide) to 79.7 F., (GReddy) and the SAE correction factor for the HKS and the GReddy being 1.00 and 1.01 for the VeilSide, we believe we were able to minimize to the extent possible the variables that might have affected the reliability of the results we derived. The numbers produced for each exhaust system were closely grouped, with no apparent aberrations that would have called into question the validity of the processes employed or the health of Bill's motor.

the facility:
As noted, all testing took place at SP Engineering located at 424 Turnbull Canyon Road in the City of Industry, CA, 91744 ((626) 333-5398; www.sp-power.com; sp@sp-power.com). As one of the pre-eminent Supra tuners in the country and, as a result of its very significant contribution to this article, TO4R.com is pleased to bring you a still photo virtual tour of the SP Engineering facilities. Since its tuning prowess is well known in the Supra community, and several of its customers' cars are members of this website, some effort was taken to show some of its handiwork on other makes and models.

acknowledgements:
We at TO4R.com wish to thank Alex Shen, Bill Robards, Jason Reinholdt and Mark Witkowski for making this article possible in order that we might bring its contents to the Supra community. Alex donated over six hours of the time of one of his two chief engineers, Jason Reinholdt, and over four hours of dyno time FREE of charge to TO4R.com (SPE normally charges $250/hour for its dyno tuning services). Bill Robards donated the use of one of the most dramatic and notorious Supras in the country and allowed nine dyno runs that, in the scheme of things, were not necessary. We all know a lot of things can happen on the dyno, most of them bad, so we want to express our sincere appreciation to Bill as a TO4R.com member making pretty close to the ultimate commitment to this article.

Jason Reinholdt, of course, prepared the car, cleaned my Veilside exhaust that Turbo magazine left all dirtied up from its recent exhaust shootout, carefully strapped the car on the dyno three times, "drove" the car on the dyno and put up with me being in the way while he was up to serious business with Bill's car.

My good friend, Mark Witkowski, dropped everything he was doing literally at a moment's notice, hopped on one of the world’s hottest Kawasaki ZX12-Rs and hightailed it to SPE on the first day of a holiday weekend to take all the pictures you've viewed and to assist me wherever necessary. I know TO4R.com is not a website for motorcycles but, if it were, this bike would be one of the charter members. Why? Well, because the ZX12-R already comes from the factory loaded for bear. Plus, the best part is that its turbocharged. At low boost (somewhere around 5.6 psi) its already producing 284 whp. The bike was built by the same fellows who had the two turbocharged Hayabusas at Vegas 2K2, one of which was making 541 whp! Those of you, like me, fond of racing bikes from a roll at 80 mph might want to make sure you and your car have had your, “Wheaties, Breakfast of Champions”, the morning of, if you ever encounter Mark and this bike out on the open road. That's Mark and the bike right below. So, when you see him at Vegas 2K3, say hello and don't forget to say thanks.

conclusions:
So, what do we know now that some, or maybe a lot, of us didn’t know before? Well, for starters, we know that bigger is almost always better when it comes to our cars. It also helps to be as straight as possible. The comparative dyno results shown above reveal the car with the largest intake, the biggest cams and the largest, straightest exhaust spools the fastest and makes the most power and torque (although the VeilSide has a smaller internal diameter than the GReddy PE, it more than makes up for it by being significantly straighter and doing without the two resonators the PE brings to the party, which helps to make the PE the quietest exhaust by far).

And, speaking of sound, although we have no video clips, trust us when we say that, on Bill’s car, the VeilSide is noticeably louder than the HKS titanium, not significantly so, but louder nevertheless. In fact, Bill says the VeilSide titanium on his red ’94 T-78 (643 whp) is louder than the HKS titanium on his blue wide body, even though the red ’94 has stock cams and the wide body comes with the 264s and more exhaust flow.

We also learned that, if Bill’s ROM tuning had occurred on the same day of our testing, the car certainly would have made more power than the 700.2 he posted the day before. Ambient air temperatures were a good 20+ F., warmer the day prior to our testing. Proof of this, we think, is the first run made with the HKS titanium exhaust which produced 694 whp, only 6 whp less than the 700.2 from the previous day at significantly less boost. Installing two stiffer wastegate springs to safely run 2-bar of boost is not inexpensive, so we’ll have to see just how greedy Bill becomes in the future.

Those wanting more spool than the stock 3.13 gears can provide would be well advised to look into the 3.73:1 ring and pinion. Look at Steve Wilson’s spool compared to everyone else’s. ‘Nuff said.

And, finally, maybe there are a few more horses (and a lot more spool!) left in Henderson’s corral that might be unleashed by the the HKS titanium (and the VeilSide intake which is already in process), although its hard to argue with an exhaust that weighs only 10 lbs. I guess we’ll just have to see what the future holds. As always and, until then, keep it on the road and out of the ditches. Peace.

Comments, rants, raves? You can email me here.

JUN 24TH '05

ryan woon updates!

JUN 22ND '05

john firth updates with new pics!

JUN 18TH '05

john firth updates with new info!

JUN 5TH '05

garth updates with 2 new pics!

MAY 18TH '05

PT71GTQ added to turbo database!

MAR 17TH '05

garth weaver joins TO4R.com!