Doyle623

My buddy has a WRX with a tial dumping to atmosphere and it sounds like a jet taking off. Kinda loud but sounds really good. I'm def. gonna dump mine to atmosphere when I put a new exhaust and tial on my car. (my first post as an offical rellist member)

Techno Duck

motoxxx, what other mods does he have on his WRX? I have heard about a dozen times from the WRX guys around my area, any WRX dumping to atmosphere will be slower than stock unless tuned / modified correctly.

MM951

Just wondering why it would cause a car to be slower?

I had at atmospheric dump on my blue Conquest and to say the least, it sounded bad-***. My friend also dumps to the atmosphere in his MK3 supra and it draws ALOT of attention from the police

Doyle623

The WRX has an STI block, 740 cc/min @ 43psi injectors, upgraded turbo, front mount, 3" exhaust, running 23 psi with 340 hp/350 ft.lb torque

toddk911

With my GURU wastegate vent to atm, it was kinda loud but at WOT so not really noticable.

But now with the Tial, it is A LOT louder when dumping.

Anyone else notice this difference???

eastendr

Resurrecting an old thread ...

We had a bit of a get together and I took some exhaust noise figures. These were taken in open air with a noise meter placed 1 metre from the exhaust, offset to the side at an angle of 45 degrees, and with DIN 'A' noise weighting. First figure is at idle, second at 3,000 rpm with no load.

924S with standard exhaust 73 / 80 dB

944T with ESS 6x4 rear box 76 / 85 dB

944T with 4" rear exhaust 74 / 85 dB

944T WUF (my car) straight through exhaust 94 / 105 dB

Obviously when the cars are under load and at 6,500 RPM

WUF also dumps the LR DPW to atmosphere. When we were in the Dyno cell this week we were reading over 130 dB at the front of the car at 16PSI / 6500RPM !

There's a video clip, but it's big (over 200 MB) HERE

I've got some boost control issues at the moment - possibly sticking wastegate valve - so about to change to a Tial to see if the boost will come on stronger.

Which size Tial do the team think I should fit - 38 or 46mm ? I'm running a LR Super 75 / #8 and intend going beyond 20 PSI.

Current 17PSI dyno plots are HERE, but that is with the original 951 head and standard porting back on. The big valve head is off at the moment and will be slightly skimmed to bring the CR back up to nearer standard.

Also, anyone know of better headers that will fin in a Right-Hand-Drive 951 ? Unfortunately, we've got a steering joint where the LHD ones don't ...

Rick

reno808

Around how much HP are you making??

eastendr

Interesting point. The Dyno Dynamics is a load dyno. The graphs show 342.5 / 290.3 FW/RW. You guys work in RWHP and from comparissons I've found on Rennlist a Dynojet may read 14% higher RWHP than the DD.

If that is correct, then DD 290.3 +14% = 320.5 RWHP, but this is open to discussion. This at 17 PSI.

Rick.

toddk911

So the 4" is actually not that loud.

So you made 320 with just Super 75 and other bolt ons? no cam, or head work etc.

Looks like you might have been a smidge lean. Got timing pulled back?

How mcuh boost do you run now or plan to??

I also have the Super 75 and plan to run 20psi.

eastendr

That wasn't the LR 4" system. It was a 3" system with a 4" tailpipe. I don't know the exact spec but I'll try to get Fen to post as it was his car.

Not quite just bolt-ons

The big valve head wasn't on for that session, and I've not started on power mapping the Wolf-3D yet - just driveability up to 3,000 RPM. The lean spike works very well to spin the turbo up, but I've got a lot of work to do on the fuel mapping yet before beginning on the timing. That will wait untill the coil-on-plug sequential is sorted later this month.

At the moment I'm running 17PSI. An 18PSI run produced another 17BHP. When the boost control problem's sorted (Swaping to a Tial) ultimate should be over 20 PSI with the big valve head once it's all mapped.

Rick.