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Slowberry Update - Dallas WannaGoFast - New 6 Speed Manual 1/2 Mile Record
Last year I pushed out a stock GT3 head gasket after about 1800 Miles on the setup that made 1500whp. My wife and I bought a new home and had a beautiful daughter 10 months ago and my free time to mess with the car became very limited for a while. We pulled the engine apart to replace gaskets and saw that my stock turbo 2 piece IMS actually loosened up. Pushed headgasket was a blessing in disguise because if that IMS let go it would have taken my whole engine out. After doing a lot of research the believed cause is engine harmonics. I decided to get the harmonic balancer which I previously was not a fan of and felt was not necessary, I also opted for a brand new one piece GT3 Cup IMS from Porsche Motorsport North America. This alone put a 2 month damper because it wasn't in stock and took a while to get. I had a GT3 Cup crank sitting that I didn't use before so I decided to throw it in now but that presented its own challenge, rod bearing is wider so I need a custom rod made. I had a rod built to my own spec from 300M which is stronger and lighter than readily available 4340 rods. Finally I decided to not put the FVD piston kit back and go with a stronger option as that kit is rated for a 1000HP ( which I can tell you for sure is underrated). Joe from AIM commissioned a set of billet Diamond Pistons for me slightly larger than FVD along with a set of Trend wrist pins - a true 3.8L now. These things looked like a work of art and I no longer have to worry about hurting anything pushing to 13-1500hp.
Finally to address the headgasket issue I ditched stock GT3 gaskets and Raceware studs for composite gaskets with fire rings and AIM custom 10mm drop in headstuds. This is huge step - using better materials now there is a 10mm stud that can hold a ton of power.
Next change in the build was probably the most time consuming one. After seeing how easily my previous 996tt was clicking off mid 9.5 second passes and some other cars starting to come out of AIM, I decided to switch tuners and standalone ECUs. I went to Emre from ESMotor. I had a lot of wiring to sort thru since my previous standalone was hardwired without a plug and play jumper harness, I also had a ton of extra wiring to sort for 12 fuel injectors, individual EGTs in each header runner, all kinds of pressure and temp sensors added for safety. Fast forward a ton of time sorting the wiring and the car is back up and running. In my opinion Emre is hands down the best overall Porsche tuner in the world whether its Syvecs or stock ECU. Support, knowledge of the specific platform intricacies and just plain hours spent tuning this particular platform, not to mention results. By the time I was done wiring my car Emre and AIM have done a dozen more Syvecs cars together and I saw most of them in person, ranging from 750whp VTG cars to 1300+ whp Spoolbus.
My previous setup made 1005whp at 20-21psi on 93 oct, 1430whp on E85 going to 8600rpm and 1501whp (only revving to 7800rpm) on Ignite racing E85 at 36psi. I was using Xona 9567 turbos with 1.03 Tial vband hotsides, the top end pull was mind bending insane. Tunnel vision and ears feel like they are getting sucked shut, however it just wasn't responsive enough for a street car to drive around and have fun with.
I downsized the turbos to Xona 8267 with .82ar Tial vband hotsides.
First full pull on wastegate with 19psi springs, making 20psi of boost it made 872whp on 93 octane pump gas. I was perfectly happy with these numbers on 93 and didn't want to push it any harder. I am not really planning to use pump gas but I still wanted to have a reliable tune up for it in case I am on pump gas and still want to floor it and rip it up. My car is a full flexfuel car so it blends pump and E85 tunes. Speaking of ethanol here are the numbers. 1312whp at 35psi of boost. I took the car out on the street and clicked off 4.2 60-130 on first attempt shifting early every time. My car revs to 8700 but tach only goes to 8000. Something I am working on addressing now. I have since improved to 3.9 and 3.8 with two shifts. I think it will do a 3.5 60-130 with one shift. I was registered for Wannagofast New Orleans 1/2 Mile. 1/2 Mile was never my thing but it seems everyone is doing it now and AIM guys had 8 other cars going down. I built this thing for street rolls and occasional digs, but whole squad was going so I gave my M3 to the wife, jumped in her Cayenne with a good friend of mine and we drove down to New Orleans where we met the rest of the guys from AIM. We unloaded, registered. The following morning event kicked off and was over 15 minutes after it started. Unfortunately a fellow racer from the east coast spun and got in a bad wreck in his GTR after hitting 217MPH. I was standing outside of my car at the starting line 3rd to go in the fast pass lane, it was a terrible thing to see. I didn't know if I would go back again or if there would even be another one of these events again. Fast forward 2 months later and the Dallas 1/2 Mile is on and I am driving a 50ft trailer half way cross country with 2 friends. I talked to a few friends who ran this particular event and they assured me it was a much better surface with significantly more room for error than at NOLA. Finally 24 hours and 1500 miles later we were in Dallas Texas, unloaded, washed and ready for action. My friends were right this airfield was wide and only had one tricky transition in the beginning of the track.Can you spot BHT? My goal for my first half mile was to go 200MPH and stretch goal was to go faster than 204.6MPH which was the 6speed Manual Porsche 1/2 Mile record being held by the new owner of my old 996tt Spoolbus.I lined up for my first pass and clicked off 196.x MPH off the trailer with an easy take off and shifting gears around 7600, was nervous and left the sunroof open lol. VBOX GPS this pass was 197.5MPH. With shifting RPM and speed improvements I right away said car had 10mph left as it sits. Next pass I did a GPS 200.8MPH completely missing 3rd gear.
Let the car cool down went up for another pass and left the traction control on so it was a slow coast, pulled right back up to the starting on a hotlap and put a VBOX GPS 204.9 MPH. 9.7 @ 165 1/4 Mile with a 1.97 60ft, 3.86 60-130MPH and a 3.1 100-150MPH. The day was done and I switched to Tequila. Later in the evening I combed thru the vbox data to see what can be improved for the next day. There were 3 things that I identified. First I have yet to launch the car, fastest take off was a 1.97 60ft and I know it can do at least a 1.7, second was an early shift from 2 to 3 gear falling out of boost just a tiny bit and last a slightly sluggish shift from 5 to 6 ( only shift where accel G dropped to zero). 208-210MPH is doable and in sight. All this without making any power increases to the car.Day 2 I show up and its cold, there is no sun and practically no one racing. Lanes are wide open. I line up, launch the car click off 1.7 60ft, nail a perfect 2-3 shift and shortly after at about a 100MPH I hit the transition dip in the runway while hazing tire in 3rd gear and all of the sudden my tires go into a full burnout and car takes a hard right and then a hard left.... a second later I am going thru the 1/8 mile traps backwards at 80 MPH and then onto the grass. I was bummed that my perfect run was cut short by a cowboy driver error and at the same time happy that I wasn't hurt and that the car also wasn't hurt. I didn't feel like laying on the cold ground and inspecting everything underneath the car to make sure it was good for another attempt so I just decided to park it up for the rest of the day.I had the fastest manual Porsche at this event with some good competition from Texans, BHT in his wild turbo GT3 who went 193.8MPH and RIX who went 198MPH with newest UHFT hot tech from Xona. Amir's ESMotor UK car 1500whp grey sequential 997TT driven by Joe @ AIM went 215MPH.I'd like to thank the AIM team, Emre, Tim and my friends who came down to support me at the event as well WannaGoFast for putting on an awesome and safe event.
Great writeup! Perfect start to my sunday with a coffe.
The IMS issue: I didn't fully understand, but do you think that your issues is related to usage of lightweight crank pulley? You did not write that so I am guessing here.
On other engine platforms removal of harmonic balancers can cause these issues. But since you rev your engine quite a lot more than stock TT all sorts issues can, and probably will, happen.
Great writeup! Perfect start to my sunday with a coffe.
The IMS issue: I didn't fully understand, but do you think that your issues is related to usage of lightweight crank pulley? You did not write that so I am guessing here.
On other engine platforms removal of harmonic balancers can cause these issues. But since you rev your engine quite a lot more than stock TT all sorts issues can, and probably will, happen.
I was using an EvoMS lightweight pulley before and also a lightweight triple carbon clutch. The stock crank pulley is not a harmonic balancer, its just a regular pulley. Now I have added a harmonic balancer to the equation. I don't think it was the extra RPM that loosened up the turbo IMS, i think it was the harmonics at rather low cruising rpm. For high RPM I have a full GT3 CUP top end. GT3 CUP Heads, GT3 Cup Cam Baskets, Custom GT3 style cams, GT3 timing chain and rails... also GT3 CUP Crank and IMS now.
I'll try and dig up some pictures of the IMS comparison.
11-27-2018, 01:51 PM
