So I've had my 991 for about a year and other than some ethanol mixing experiments I did and one Shift Sector event it just sits in my garage. My ethanol experiment with just the GIAC tune was fun and had great results. Did a 6.6 second 60-130mph run my only try and then at Shift Sector ran heads up with the fastest stage 2+ 991 in SoCal (the PP tuned FBO car doing 166 in the 1/2 mile). These limited data points showed how well the stock hardware (exhaust and intercoolers) faired in good and bad conditions.


I have been following the progression of some of the upgraded turbo cars and nothing really interested me until Mark Blackwell did his stage 4 with the newer Tial 68 w/HTZ wheel. That turbo got me thinking that maybe I could do one last test on the stock hardware - by bolting up the 68's on the stock exhaust and intercoolers and turning the turbos up to 1.7 bar to see if it would work.


Many people were skeptical. Hell I was skeptical. But if it worked it would be pretty insane and talk about cost effective. I got these turbos from Tom at Champion Motorsports and they were less than the cost of an aftermarket exhaust.


So the car went to Autotalent for the install and when I got it back I drove it on the stock map for a couple days. Funny it behaved just like a stock car at stock boost levels. Imperceptible lag. Mark told me there was no lag on these turbos and he was right.


Then it was time for the car to go to GIAC. GIAC installed their base map for the 68/htz turbo + FBO and strapped it on their dyno. GIAC uses a Mustang dyno and it is calibrated (almost exactly like the GMG dyno) to read very low. Case in point, my 997.2 bone stock made 501/536 AWHP/TQ on the Cobb mustang dyno. On GIAC was something like 435. Fully modded my 997.2 made 566 and it just did a 167.44 1/2 mile and 138.9 1/4 mile (uphill).


Now tune-only my 991 put down 540 AWHP on the GIAC dyno on my pump+ethanol mix which was very strong for that dyno and made sense for my 60-130 time. I was hoping with the turbos it would hit 580.


So to everyone's surprise the first run on pump it did 597. Then we tossed some MS109 and it did 630. 630 is insane on that dyno. At 620 the rods in a Mezger will bend. As a comparison, a GMG TT R8 v10 did 666. The logs looked beautiful. IAT's were in check. EGT's good. Dyno is one thing. How is it going to perform on the street or at an event?


So I did some runs on MS109 to see how it would do. Had the vBox and the GIAC logger. I went to my same 60-130 spot. It's perfect. Middle of nowhere and a flat slope. Same place I did my earlier 6.6 tune-only run.


First WOT run something felt off. There was some cutting and oscillation on the top end. 60-130's were mid-6's. At 630 wheel I was expecting low-mid 5's. Something was off. I did 10 back to back 60-130's in race mode, then pump mode. Actually got faster in pump mode. So something was off. Send the logs to GIAC and confirmed that EGT's were way too high. I tried two more times with different gas mixtures. Second try was with MS109 and some ethanol. Maybe the ethanol would lower combustion temps enough to allow the EGTs to stay in check. Nope. Then tried for a third time with a mix of pump gas and ethanol. Weird thing is that the car actually got faster on pump gas and was doing low 6 second 60-130's on pump map with pump+ethanol. Obviously this did not work in the real world.


Anyway I have a GMG catless exhaust, Champion intercoolers, upgraded diverter valves and a BMC air filter on the way. Will go in for a proper tune. I will see what it can do with this combination first. I don't want to do methanol on this car but I will continue to see what it can do with some ethanol mixes assuming I haven't tapped the stock fuel system.


Anyway figured I would share just in case anyone else had the same crazy idea. Sorry but it didn't work.

EDIT: The TT R8 v10 that did 666 wheel on the GIAC dyno was a GMG not UGR build.

 

I conclude that this tuning takes a lot of work and each car is different. Look how much work Carlos put into getting his numbers down. I have tried and tried but not had much success with mine and I am doing all the things as instructed but it won't get much better than it is. Your experience with the meth that day was really amazing so I hope you can dial in a good combo on this car with some additions, like you say though, this wasn't it. I didn't see any real gains by taking the cats off other than the car is louder and it is stronger on the back stretch at COTA but for 1/4, nothing.

 

We have a lot of time in getting this setup done and working well. I am sure with time you guys will get it more sorted out.

-Mitch

 

Hi Mitch, hope all is well. So a point of clarification please - are you saying you tried an upgraded turbo on a car with stock hardware (stock exhaust, stock intercoolers, etc)? I thought I was the only one to try this. Thx.

 

LB- thanks for continuing to pioneer trying new things and sharing your results honestly, both good and bad.

Is there any chance you could try just the catless exhaust without the upgraded intercoolers? I'm curious how much the of the IAT issue is the factory cats/exhaust vs. intercooler.

 

Hey what's up my friend. Yeah some of us have a much different moral compass. There's no glory in cheating.

So I did think about first doing the exhaust, but I'm going to be running a lot of boost (more than 1.7bar now) and it isn't just the IAT's that I'm necessarily worried about but also the amount of flow of the stock intercoolers can handle. Remember they can be very restrictive for air flow.

Mark Blackwell is running the Champion intercoolers and his testing showed that they flowed incredibly well, even better than the other brand intercoolers he tried. So all that said, and the fact that it's really cheap to have the intercoolers installed at the same time as the exhaust, I figured this would be the best option.

Car should be going in late this week or early next week. I'm excited

 

Kudos for trying new things Adam. I didn't really think you would be able to pull it off on stock cats but was curious to see. That would have been the budget setup of all setups IMO. I think both I and the forum are glad you shared honest results you had though. Let's see what you do when you turn things up after getting the supporting mods.
Any plans for meth? I don't think you will be able to take advantage of the ethanol blends once you are tuned for the bigger turbos. Car should be plenty capable with or without it.

 

Adam that would have been incredible if it would have worked, glad you have your goodies on the way your not gonna bust an axle with the 991 you should bring that thing to the Red List. What about NoFlyZone in December are you going to that?

 

Special delivery on its way out to CA for you today

 

Excited stuff Adam! Best luck with your results!


BTW thanks for the recent video run of your 997.2, without having to be asked!!..LOL!




https://www.6speedonline.com/forums/...re-nfz-ca.html

 

Keeping an eye on this, Adam! Looking for the next Omegamotorsport company car... haha. This platform impresses me more and more.

 

Now were talking Adam!

 

I have already had this experience on GIAC stage two (tune and exhaust) versus GIAC Stage 2+ (tune, exhaust and upgraded ICs).

On GIAC stage 2 which is with stock turbos and stock ICs, the extra heat generated by increased turbo boost (and consequent increased friction of the turbo blades against the air) is way too much for the stock intercoolers to overcome. You get one fast run and then the ECU dials power right back to stock to deal with The escalating IATs. (theoretically you could avoid this heats up power loss if your tune told the EC you to ignore the escalating I ATs but if you do that you're risking ruining your Turbos and other things with all the extra heat and I would never risk premature turbo failure in my car).

I put several very detailed threads with Timeslips a long while ago which proved this in action. It would be no different and probably much worse with a turbo upgrade car. You're just generating way too much heat for those tiny, puny featherweight factory intercoolers to overcome. Once you take a factory intercoolers out of the car and put it in your hands and realize how tiny and paperweight it is you will understand why it lacks a sufficient flow rate to cool down the air from the tune let alone from upgraded turbos. The result of trying upgraded turbos with stock intercoolers is you will generate far too much heat for the stock intercoolers to overcome and the ECU will very very quickly dialback power to stock levels or you ask the tuner to fool the ECU into ignoring the increased IATs which will make your turbos fail much much faster especially with our supersensitive VTGs. You might be able to get around this problem if you didn't want to upgrade the intercoolers with a meth injection kit but I'm not a big expert on meth. I know it cools everything way down but I can't vouch for whether it will have a significant enough impact to stop heat soak in that condition with upgraded turbos and stock intercoolers. I leave that for the technical experts here.

Here are my heat soak threads:

https://www.6speedonline.com/forums/...oss-ideas.html

https://www.6speedonline.com/forums/...rap-speed.html

https://www.6speedonline.com/forums/...dragstrip.html

 

Hi Chris. Since I'm taking this slow, I'm just sticking with the basics for now to see how the car does with the turbos intercoolers and exhaust. I really want to run e30 with this combination and I am afraid of running out of fuel so it might not work. But I will try. I was very happy when the car just had the GIAC tune and no other mods, that I could run the race map on e30 without any timing correction. This means anyone with stock turbos and FBO should have no problem with this gasoline mix.

So I'll try e30 and go from there. I know with my 997.2 with recently-installed dual 630cc jets that simply turning meth on is good for 50-75 HP. Partly because it would have otherwise run out of fuel. So not sure the 991 will respond as well but it's possible. So I will probably end up with meth someday and that will likely allow me to run an ethanol bend.

Yeah it would have been awesome if it worked. Odds were against me but it's fun to tinker. I'm lucky to have GIAC around the corner to appease my appetite to try new stuff out.

For sure I'll be hitting the events this winter with you guys. With the stock PZero's I won't need to worry about busting another axle. Drag racing not really my thing so I'll let the die-hards blaze the trail. But definitely look forward to the half mile and track events this winter with both the 991 and 997.2.

arriving tomorrow

Thanks brother. That event was a blast!

Hmmm. Sell the R8 and let's talk brother