I'm not impressed by those numbers! But that car has some nice mods.

 

If the remote gate is setup and functioning properly why would there have to be a loss in spoolup, Mikey? The entire system from the turbine housing's bypass port out to the remote gate's exit valve would be at the same internal pressure, wouldn't it? Just arguing for argument's sake, buddy!

 

Because if you look at the twinscroll housing you have two discharge ports that remain separate during the spoolup due to the stock flapper closing them both off. If you open the flapper/remove it you allow the two discharge ports, during spoolup, to mix pre-external gate and not remain separate, removing the true twinscroll effect. Mike at AWD and a few other people have tested removing the flapper and they lost 400-500rpm due to the fact that it is technically making it spool like a single scroll rather a twinscroll.

I have not had a chance to test this myself, so I am refering to other peoples testing. We will be doing this soon however.

The op graph doesn't provide a good comparison for spool since the before and after dyno were not started at the same rpm...

Mikey

 

You can't really say if you are/not impressed by the numbers. We don't know all the data about the car yet. main thing being boost!

Mikey

 

Mikey,

With the MAP recirculating O2 don't the discharge ports remain separated until after the TiAL MVS WG? There is no pre-mix of exhaust gases because the TiAL WG is closed, right? I don't understand how you lose the twinscroll effect with this setup. Not doubting you'll lose spool with this setup, just trying to understand how.

"Because if you look at the twinscroll housing you have two discharge ports that remain separate during the spoolup due to the stock flapper (TiAL MVS WG) closing them both off." Couldn't you make the same statement about the MAP recirc O2? Aren't the stock flapper and TiAL MVS WG performing the same function?

Any further explanation is much appreciated. I was really hoping to go this route with my next round of mods. But if I'm going to lose 400-500 rpm during spool up, I should really just keep my TiTek O2 housing. Already tried the MAP O2 Open dump, and just to loud for my tastes.

"Recirculated wastegate dump (Pictured): Standard O2 housing configurations recirculate the wastegate gases just inches away from the turbine outlet resulting in turbulence and decreased performance. Our unit recirculates the wastegate gases as far away from the turbine outlet as possible to provide you with the best possible performance without the additional noise from the external dump."

 

churchja, as soon as the internal wastegate flapper is opened, the effect of the twinscroll exhaust housing are all but lost.
This is because the flapper isolates the scrolls for each other. Once it's open, the pulse energy and exhaust flow can mix between scrolls. As i've already told mikey, i've actually tested this. With my wastegate the same setup as this item, once i put the internal wastegate back i gain a significant amount of spool/reponse back. 2nd gear, 17psi was being made @ 5000rpm. With the internal actuator on (and external still there), 17psi was being made @ 4400. Off boost response and drivability went up.

I didn't have my internal flapper welded open. I just lockwired it in the open position.
as seen here


All these results were obtained with a stock evo 4-6 wastegate actuator that opens at 12psi.

 

Off-topic discussion regarding the MAP Stainless Steel O2 Eliminator Downpipe for Evolution 9

Moved to (Post #13): https://www.evolutionm.net/forums/en...ml#post8501152

Junior: What size spring did you use on the MVS 38mm WG?

 

this is way OT.
Start another thread if you want i'll post in there.
I'll PM you what i mean.

Cheers, Mike

 

Not sure, I will have to have Junior check the before and after graphs and see.

Keith

 

seriously? you honestly think it made 774tq on 93oct? come on...... LOL. the graph is mega ****ed up, something happened to that dyno during the runs.

I want to see boost plot also..46whp gain for just swapping a restrictive exhaust piece is interesting. unless the car benefited from the other mods, but i dont think so as much as the exhaust mod made most the diff.

 

Do you have any idea where this post can be found?

 

Sorry for the late and short reply. I am away and have very little phone/internet access.

The small loss in low end/spool was more then likely the addition of the 3" IC pipes.
Boost was set to 28psi on BOTH the baseline and then the tune. I am sure with a little more tweaking of the WGDC I can get it to come in a little quicker. The flash cable died toward the last few pulls so we called it a night. I am sure another 15-20whp was left on the table, but it was late and 106 degrees in the dyno room.

Jr

 

and NO I no longer tune @ THE SHOP CT, I have not tuned there for a little under 2 months now. If any one needs me you can shoot me a PM or call TurboTrixRacing and ask for JR

 

That is a great tune man for 93 and 28psi. Room on the table just means you tuned the car safely

 

Sure, Mikey, theoretically it is supposed to function exactly in the manner which you have outlined above. However, this is just theory and the actual extent to which TS helps spoolup varies from case to case.

As long as the flapper valve remains closed on its seat there exists a separation of pulses. This is dependent on WG spring pressure/WG preload etc.

Every user runs a different amount of WG spring pressure. As soon as the flapper valve starts to lift or crack then the TS effect is compromised or lost, right?