2000 Audi S4Scarlet SedanIf JJ's RS4 Wagon is pretty damn fast, then Mark Slazak's 750whp RS4 Sedan can only be described as ludicrous.
Mark is the President of Autospeed Performance in Voorhees, NJ. He went for total performance from his 2000 S4 Sedan. And if the name of the shop sounds familiar, it's because Autospeed (ASP) worked with Eurocode Tuning at the '07 etGP, powering its S4 straight into the winner's circle.
Mark's Laser red example has a fully built engine, and virtually everything on the car has been upgraded. Listing all the parts would take another three pages, so we'll cut to the core.
ASP-developed engine and turbo...
ASP-developed engine and turbo kit with twin GT2871s puts down 750whp
The block has been punched out to an even three liters, and a stroker crank is connected to forged rods with forged 8.5:1 pistons. Ported and polished heads and cams from the naturally-aspirated Audi 2.8 V6 were added, along with Ferrea valvetrain components to let the big-six rev out to 8500rpm.
Fueling is critical at these boost levels (37psi), so twin Bosch Motorsport fuel pumps feed ASP fuel rails and 750cc RC Engineering injectors, set to a base fuel pressure of six-bar and regulated by an Aeromotive FPR.
The big turbo kit is one of ASP's own, based around Garrett GT2871 ball-bearing turbos - the largest that will fit the stock locations. ASP tubular manifolds, 3" downpipes and an ASP TruDual exhaust allow spent juice to exit quickly.
ASP also offers custom Motronic tuning with its SpeedPort flash-load programs, and Mark credits the outstanding power delivery to their ability to read and modify the Bosch maps. "If you're going to make parts for the car, you need decent tuning," He said. "When we started [custom tuning] is when we started getting serious about high horsepower cars. Without the engine management, it didn't matter what we tried to build, it just wouldn't run right."
That power, as mentioned, is a dyno-proven 750whp at 37psi on VP109 fuel, and an impressive 600whp at 28psi on 93-octane. "The power is really linear," Mark said. "It's not all or nothing. There's a good amount of power low down and it's not laggy but it comes on and just keeps building and building."
The chassis has been upgraded with Penske/StartUp Racing coilovers, 355mm StopTech brakes running ST60 six-piston calipers and either HRE or Work wheels, depending on whether it's used on the track or street.
The RS4 widebody was built almost entirely by ASP and was initially more of a cosmetic upgrade. "We ended up doing it all in-house except for the paint. I've done two so far but don't think I'd want to do a third," Mark laughed.
19" HREs for show, but these...
19" HREs for show, but these 18x9.5" work emotion Kai wheels with Hoosier tires are intended to go
These days, Mark stuffs as much rubber as he can under the wide fenders, running 275/35 R18 Hoosier R6 tires for racing. This still isn't enough at the track, as the car can spin through third gear when running full boost and race fuel. Impressed? The guys from Team Champion Racing were (they campaign the Audi R10 TDI racecar in the US). "The crew from the R10 program were a little skeptical," Mark continues. "I told them we had 750hp and they kind of rolled their eyes. Talk is cheap so I took them for a ride. I gave one guy a ride on the 93-octane tune, and he looked at me, white as a ghost and asked if I'd take the other three guys for a ride because they're never gonna believe how the car was. So that was really cool for us."
But despite big horsepower numbers, the car was designed first and foremost as a smooth performer for the track or the street, and the base turbo kit is available off the shelf from Autospeed Performance.
Mark also has ambitious ideas, such as his SpeedPort tuning, which will be available with up to eight different maps, optimizing the car for every situation. "With eight profiles we can give you tunes not only for octane, but for track choice as well," Mark said.
Given the quality ingredients Mark and JJ had to work with, it's no wonder they each cooked up outstanding vehicles. Their different approach, direction and results show it's up to each of us to mix our own perfect recipe.