The R3gister - Race Rally Research (R3)

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Having tolerated the constant buzzing and ringing of the cracked R3-Hotbits stock 4-2-1 header and later fullblown lorry-sounding orchestra after running at Sepang, I got a R3-spec Hotbits 4-1 header installed. Prozac, owner of the first ever retail version of the Satria R3 (series number 0006), offloaded his 4-1 exhaust header to me on the cheap. I had initially wanted his stock 4-2-1 header through a one-to-one swap with my stock bonnet, but the chance to own the bronzy stainless steel header was just too difficult to pass up.

Pic borrowed from The SP Files
The 4-1 header is similar in spec and looks to the R3 version above. There is a difference in design with original 4-1 Hotbits developed headers, just to note. Theoretically speaking, a longer primary will create more torque rpms below peak torque. It does this by increasing air flow velocity and expels spent exhaust gases much more efficiently than a 4-2-1 header. Want to know more? Read this (thanks to LLSaw of The SP Files).

It has always been a assumption (which has in recent times proven wrong) that you lose low to mid range torque in 4-1 header designs. Header designs have much improved, fusing the 4-2-1 layout with 4-1 lengths - hence the birth of longer primary 4-2-1 headers as well.

Since installation by the boys at R3 (thanks Suhaimi, you rock dude!), results through my sensitive butt dyno, have been surprising. Suhaimi had mentioned slight throttle vagueness i.e. lag at lower rpms when we were heading back to R3/Proton HQ. However, my drive back home revealed ‘a different car’, so to speak.

There is slight loss in torque in the lower range rpms. At lower rpms, I refer to anything below 3,000 revolutions. Where torque used to kick in early at 2,500rpms, the presence of the 4-1 header has shifted that to around 3,500rpm. It’s not a substantial loss, through my experience, but still notable. The surprise comes at around 5,000rpms. Be prepared for a seemingly endless ability to pull. And boy does it pull! The torque does not kick it in a lump as it did at 4,000rpm using the stock header, but its incredibly well-spread and smooth. It’s pretty amazing how it pulls smoothly to the upper ranges towards the redline. Sweet. Stay in the region of 5,000-6,000rpms in 3rd and 4th gear and you’ll know what I mean. I’m not afraid to say that it feels almost as if I’m running bigger piping. The car feels a lot more ‘free’.

Exhaust note overall has changed too. The burble at idle is crisp and misleadingly tame. Try it at full throttle and enjoy the aural orchestra! Very full, very solid. Menacing and addictive.

Initial reports of the 4-1 header on Stage 2 cams weren’t especially positive, with overall power loss on dyno. The header however increased peak power on a few SGTis and seem to work best with ported heads. I would like to do a dyno run just to look at the torque/power curve to compare with my previous dyno. From my own experience with the car (albeit brief with the new 4-1 header), I feel it has increased peak power by at least 3-5bhp and overall gains across the rev range. Although I am disinterested in peak power readings in general, I’m confident that my Satria SR3 has touched the 140whp mark with this header mod and hope to confirm this with a dyno session.

I’m also looking forward to port the head, which would conclude my engine mods on this hot hatch, and concentrate on the drivetrain, suspension and brakes. One important things to note. R3 had to remove the 4-point under chassis tie bar to fit the 4-1 header. If you plan to have a similar header installed, be prepared for this.

Coming right up is a smallish review on the Symborski gear shift aluminium bushes! Stay tuned.