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It's potentially a catagory killer product, no surprise that other manufacturers are concerned. The catted version has an even larger audience, I'm waiting to see it.
This is why we're trying to stay on task.
1. Finish the orders we have
2. Build and Test the Catted Version 991-3/RS systems
3. Build and Test the Catted and non catted version of the GT4 systems.
Question.....without doing ECU flash/tune, does the OEM ECU system eventually adjust itself & negate (or even reduce) any power gains after adding aftermarket headers, exhaust etc etc?
THX
Originally Posted by MileHigh911
This is a great question. Charles...what are the limiting measurements with concerns to the OEM ECU? Doesn't the ECU constantly measure torque? Would one have to get a "ECU tune" to keep these systems from controlling the parameters?
While we need to do some long term testing (this is what my car is about...). We have mechanically changed the volumetric efficiency of the engine, so regardless there is more air in the cylinder the engine is able to use to produce meaningful power gains. What we found on the stock ecu with our headers is it doesn't adjust fueling long term, it's adjusting on the fly constantly. This tells me as long as you don't bump into a torque limiter, the car will keep on doing what it's been doing without too much regard for the past (this is unlike the 997's which have a long term adder...).
Cam timing doesn't have many maps to follow or to change overtime, so I don't expect cam timing to "wander" and change cylinder fill.
Ignition advance, there's very little ignition advance in the maps to start with, so again, as long as there isn't a knock signal (and there isn't) then don't expect it to change.
As far as injector duty, as Charles said the fuel pressure is a variable with the DI cars so you have 2 ***** to turn for this, and the car was only adding 8-10% fuel to hit the lambda targets, well within variance for the stock ecu to manage.
While we don't know, and will need to test it, the physical changes are harder for the car to ignore and negate or change as if it did it's starts to violate lambda targets and knock thresholds and will put it all back so the sensors are happy!
As Charles said, the best combination for any modification to the volumetric efficiency of the engine is the combo of hard parts (headers, air filter, etc...) and a tune to take advantage of the hard parts. This is exactly what we've been working on and will continue to work on and refine!
1. Build and Test the Catted version of the GT4 systems.
2. Build and Test the Catted Version 991-3/RS systems
3. Finish the orders we have
Jaime fixed it for you.
Seriously, appreciate all the work on this. I know you guys are working hard right now, but can you give me some kind of timeline on when the catted GT4 version might be available. I might be up for a road trip this spring/summer for an install, and will need to plan ahead.
Seriously, appreciate all the work on this. I know you guys are working hard right now, but can you give me some kind of timeline on when the catted GT4 version might be available. I might be up for a road trip this spring/summer for an install, and will need to plan ahead.
Originally Posted by GT3 KSA
when do you think approximately this can be ready (timeline, give or take a few months)
These are the best kinds of questions, means we're doing something right! From a practical matter we don't have our GT4 yet to test on. We were told the ship made dock in CT/NY a few days ago and it's on it's way to Dallas. Our business partner is flying down to get it and drive it home, break it in so we can hit the ground running. The design Charles has worked out in his head already as he got a chance to look under a GT4 at another shop for a few hours.
Realistically March will be spent working and making the 991 Gt3 catted systems as we have a car to test on easily. We should be able to design and test the catted system. We'll open up pre orders after we have it tested and dyno results up so we can get an idea on the number of cats to order and mandrel bends to order.
Once the GT4 gets here, we'll get started in earnest on it. I'd expect we have the design finalized and tested by the end of April.
Then Charles will have to clone himself to knock out the 991 catted systems and GT4 systems in addition to our orignal 991 GT3/RS race headers
Looking forward to the headers w/ cats for the GT4. My car will not be here until May so figure I want to put 500-1000 miles on it before putting on some Mods. I like your approach and results with your headers so willing to wait. Another Vendor looks like they got a pretty good tune for the GT4 that they just announced on the GT4 forum. I think your headers with this tune could be a nice bump
Just grabbed others comments from previously in the thread, as a refresher...
Jamie,
When looking at the increase that you're getting on a standard 991 GT3 of 55 hp and 30 pounds of torque at the wheel I am wondering if you are getting the same increased results with the 911 RS GT3?
I was wondering if you had a comparison chart of the 911 GT3 RS getting dynode with and without your headers?
If you are not getting the same increases in horsepower and torque as the 911 GT3 can you explain why it's not considering that there is a 4 L motor being used in the RS?
When looking at the increase that you're getting on a standard 991 GT3 of 55 hp and 30 pounds of torque at the wheel I am wondering if you are getting the same increased results with the 911 RS GT3?
I was wondering if you had a comparison chart of the 911 GT3 RS getting dynode with and without your headers?
If you are not getting the same increases in horsepower and torque as the 911 GT3 can you explain why it's not considering that there is a 4 L motor being used in the RS?
Thank you.
Hi Loungedog.
We posted the RS results in the thread that was deleted... Sigh. Also on our dyno we saw 40whp and 30wtq gains. Matts car on Titan Motorsports dyno showed more.
Below is SSTHO's white RS on our dyno. 20whp peak gains and 25whp max gains and about 25+wtq gains at 4500 rpm or so.
We believe the reason we're not seeing higher gains on the RS are due to the torque limiters in the Ecu, you can see a bit of a stair step nature to the dyno. This isn't too much of a surprise as the same Ecu was used (different maps) and similar transmissions.
We'll know a bit more after we get an RS on the dyno with our headers to tune! Feel like a drive to Maryland?
We posted the RS results in the thread that was deleted... Sigh. Also on our dyno we saw 40whp and 30wtq gains. Matts car on Titan Motorsports dyno showed more.
Below is SSTHO's white RS on our dyno. 20whp peak gains and 25whp max gains and about 25+wtq gains at 4500 rpm or so.
We believe the reason we're not seeing higher gains on the RS are due to the torque limiters in the Ecu, you can see a bit of a stair step nature to the dyno. This isn't too much of a surprise as the same Ecu was used (different maps) and similar transmissions.
We'll know a bit more after we get an RS on the dyno with our headers to tune! Feel like a drive to Maryland?
Can't wait to see what you can do with a tune on the RS. More HP and Torque bring it on!!
03-03-2016, 05:54 PM
