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Cayman The Destroyer!
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My engine retains the 78 mm stroke and the pistons are 99.5 mm. I chose not to stroke the engine at all because I was not willing to take the risk of unintentional results. I think Diverdog made the wise choice by going to a 3.8 block because the block is designed for the longer strokes.

Different strokes for different folks
Changing the stroke on a turbo engine plays havoc with the DME programming. I was aware of this going in to the project but it is more complex that I first thought. tuning found 100hp vs the 3.4L programming.
 

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The problem is not physically stroking the engine, the problem is the DME as diverdog stated.
 

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Discussion Starter · #43 ·
That is correct. We set the piston crown profile on my car to reduce the compression ratio to 10:1. The profile of the first gen engine is also very different that the profile for a DFI engine. The tune for the NA setup is different from the tune of forced induction engine. Then add methanol and it is yet another map.
 

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Discussion Starter · #44 ·
Well, I finally went to TPC to get my Sally back. Mike Levitas just had to have one last drive though, so he suggested a quick drive to make sure the brake pads were properly bedded on the new Precision Friction rotors, so away we went. The car will literally plant you against the seat back. We talked about where we had been on this journey. He wanted to make sure I was happy. After driving the car for 3 hours, unfortunately, mostly in traffic, I can report that I am completely happy, even thrilled.

I don't have the dyno chart yet due to some server issues, Mike tuned it to produce a very flat torque curve and we ended up at 537 WHP. For those who like to talk crank HP, that is 645 for 15% loss and 655 for 18% loss. Mike reported that we could have gone higher, but the wheels were beginning to spin on the dyno at about 6000 rpm. I don't remember the final torque number, but I will report it along with the chart.

Technical Discussion

Mike tuned the car at 10 PSI boost to set the maximum benefit of the methanol. I seriously doubt that I will ever operate the car at 10 just because of wear and tear and reliance on methanol injection. The tune at 4 psi boost (the low boost setting) is completely independent of the methanol and I could run the car at low boost with the methanol off if I choose. At 6 psi (high boost), the tune will accommodate a methanol flow failure by detuning.
The methanol injection begins at about 2 psi boost and increases as boost and rpm increase. I do not know the flow rate, but it is low. In normal driving conditions, meth usage is zero. In all the driving Mike did to seat the piston rings and to get the methanol onset and ramp evaluated on the street and 8 dyno pulls (I think), total methanol consumption was about 1 quart. I'll keep records and report findings, especially on the track.

Driving impressions

The car accelerates in 3rd gear like it did in 2nd before the build. The pull is constant and relentless. Exactly what I ordered. In full pedal accelerations from low rpm, the turbo onset is noticeable but smooth and the onset and ramp-up of methanol is not detectable and is completely linear. In linear pedal pushes, the torque progression is linear and completely predictable. An absolute perfect set up.
I was worried about the Sachs racing clutch, but it is very nearly as controllable as the stock clutch. I did notice a slight shudder in reverse, but the onset and the progression of torque is very predictable and controllable. Pedal effort seems a little heavier, but not so much as I would notice it if I didn't know the clutch had been changed. I may even be kidding myself.
The exhaust has a slightly lower, fuller tone to it. At full throttle at high rpm, it is more of a howl than a scream. I love it.
The combination of the GT3 master cylinder and the Precision Friction 330 mm rotor improve the brake feel and modulation noticeably. The brake pedal is higher and much harder than stock and the added radius on the rotor provides great brake feel.
The only evaluation of the Guard LSD I did was unintentional. Accelerating from a stop sign, at about 3500 rpm in first, I smoothly floored the pedal. After an initial insane thrust, PSM intervened with throttle pulls. I looked in the rear view mirror to see two black stripes on the pavement. During the acceleration, I noticed no side force or directional disturbance.

The bottom line is this: I have taken a well mannered, reasonably restrained young lady and turned her into a howling Amazon warrior princess. I can't wait to get her on the track and begin to learn how to coordinate our moves for mutual satisfaction.

Thanks to the highly capable and professional crew at TPC Racing. They gave me exactly what I wanted, gave exceptional technical advice, and performed every task with accuracy and care. If I had to do it over again, I'd do it exactly the same way with exactly the same people.
 

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Cayman The Destroyer!
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Kenny, this must be the week for 600hp Cayman's! I'm glad you are so happy with the mods to your "Sally". Be careful, who knows what will happen when the girl next door drinks the magic turbo potion and turns into an Amazon Princess. Just remember it's OK to ride her hard but always stay on "top" of the situation!:burnout:
 
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Discussion Starter · #47 ·
I know what you mean. I'll try to stay in control. On the other hand, some of the most memorable times in my life is when the girl "took charge" ;)
 

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Discussion Starter · #48 ·
My wife drove Sally yesterday. Most of the drive was in traffic. She said the clutch was no problem at all. She actually likes the new clutch more than the old. She said the feel is more precise. She did experience the slight shudder in reverse. She also said she had too much fun in second gear to ever shift to third.:)
 

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Very glad to hear that you and your wife are enjoying your car! We finally got the network issues sorted and have emailed you the dyno charts. I will post them as well in a separate thread once I have videos and photos edited as well as a write up.

Keep having a blast with Sally!
 

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Discussion Starter · #50 ·
And a blast she is.
She spins the tires in low boost. Street-warm tires, 2500 rpm, first gear, clutch fully engaged, stroke the gas pedal to prevent outrunning weight transfer, resulting in full throttle at about 3200 rpm. It stays hooked up until about 4500 rpm then breaks away. Apparently I am very near the grip limit because the torque curve is essentially flat in low boost. Beautiful curve. Partial throttle accels seem to be quite linear. I have no reason to believe that the throttle will be very predictable on the track. More sensitive, yes, but predictable. Also, significant torque is available at a lower RPM than with the 3.4.

High boost is somewhere between inspirational and insane. First gear accels can only be done at partial throttle, maybe 80%. It is easy to break the wheels away. Second gear accels pull harder as the rpm increases. I have limited experience with third gear because I am on the street and there ain't no Autobahn here in the US.


The more I get to know her, the more I like the new Sally. I've got a lot to learn. With the new 60/40 LSD, I get to start experimenting with sway bar and tire pressure settings to match her response to my style. This is going to be FUN!!
 

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sounds really great - fwiw I always wondered how trapped one must feel not being able to run as fast as it goes ;)

I am very lucky the next autobahn part here with no speed limit is pratically 5 minute drive away from my home :)

but don't worry about it because the number of insanely higher hp'ed cars in the area is also not too small - the current GTR's are just insane - or even a well tuned 911 TT is scary fast - that's why we have a car club here - called club 300 plus - meaning club of the cars driving over 300 km/h speed :)

enjoy your sally it sounds the right owner got the right mod to his car if you are so sensitive to details and have fun exploring them - perfect match :cheers:
 

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Cayman The Destroyer!
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Torque is a beautiful thing! Your Sally is now a super model, olympic athlete. Beautiful, svelte, nimble and oh so fast. Much better looking than big brother 911, and now capable of kicking his butt.

Driving on public roads is always an exercise in restraint as using this kind of power is very addictive. Like you, I can't wait for some track time:cheers:
 

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Discussion Starter · #53 ·
Yes. TPC tuned low boost for flat torque. Mission accomplished. From 3000 rpm to 7000 rpm, torque variation is less than + or - 5%. Life doesn't get any better than that.
 

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Discussion Starter · #54 ·
I can't wait to get her back on the track. I'm seriously considering wider wheels and tires. I'll wait to get some track experience and figure out the sway bar and pressure settings for a good setup, but I am thinking about wider tires up front to help counter the understeer inherent to the LSD. Changing sway bar settings is a heck of a lot cheaper than changing wheels, so I definitely want to get enough experience that I can make an informed decision on absolute size and stagger. So many parameters to play with.:)

I just think Sally would like a new set of dancing shoes to add grace and elegance to her new athleticism.
 

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Discussion Starter · #56 ·
What size tires are you running now? Stock? 235/265 ?

I think I'm going to go with 275's on the rear for my next tire swap.

I would think with your set up you'd need like 295's on the rear.
Yes, stock 19's, 235/35 front, 265/35 rear. I'd like to go to a 295 or 300 in the rear. I'd like to go to a 9.5 or 10 inch front wheel and a 10.5 or 11 in the rear depending on what I can fit. I know if I put too much rubber up front that I will make her tail happy and we try to keep that kind of stuff out of the public eye.

I also want to play with the aero with a full width front lip with fender strake extensions and a larger spoiler/wing in the rear that will obviously affect the setup. I'm thinking I would be smarter to do the aero first and then select the tire stagger.
 

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Cayman The Destroyer!
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I have a good set of BFG R1's 245X275 on 8.5x10" wheels. Full width splitter and larger rear spoiler. Guard LSD & TPC bars. I'm going to use up these tires before trying anything larger. The only options I have that will fit as an upgrade would be 245x295- Hoosiers. The 255 Hoosier is really wide and may not fit up front.

I wish I would have done a real wing in back but we shall see how the existing setup works. I like the idea of more rear grip on high speed turns.
 

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Discussion Starter · #58 ·
I've been quite busy lately and have had only a few opportunities to drive my car. On Monday, I took her back to TPC to update the nozzle and pump duty cycle schedule. The reason for the change is system optimization. With the original nozzle size selection, we were operating the pump on the low side of the operating band. While the original installation provided very good performance, we were not operating the pump in the duty cycle range that provides the best pump response to flow demand changes, so Mike figured out that by decreasing the nozzle size, we get the pump operating at a higher net pressure and get a better nozzle spray pattern and faster, more controlled response. It also gave me the opportunity to take a few pics of the installation.

Here is a pic of the engine compartment installation of the methanol routing


The braided line comes from the pressure side of the pump in the forward trunk. The methanol then goes through a check valve then to the nozzle that is installed in the aluminum duct that provides the T to the compressor bypass valve. Here is the nozzle fitting in more detail

and finally, the nozzle protrudes slightly into the duct


After the install, Mike Levitas and I took her for a spin to road tune the injection schedule that involved several full throttle accels at various duty cycle settings to maximize the torque. Mike's initial guess on the schedule was close, so the process didn't take long.

Here is what I have noticed just operating on the street. The torque rise at injection onset is even smoother and throttle modulations are more precise. Granted, the impressions are based on a few accels and several throttle modulations on a few interstate entrance/exit ramps. With this setup, it is not hard to power the back end out from under the car, but there is still very adequate pedal sensitivity to control the slide in low boost. I have not yet worked up the nerve to try it in the high boost setting.

The car continues to amaze me and make me grin. The biggest problem I have had with the car is staying off the RPM limiter. I never realized how much I used the sensation of torque decrease at high RPM as a shift cue. This car is still pulling like crazy when the limiter intervenes. I can't wait to get some real performance numbers.
 

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Hey Ken what an amazing journey! This is one of my favorite threads. Have you been able to get 0-60 and 1/4 mile times? When you do please post, I'm curious to death to see what times your Sally can do.....

Cheers!
 

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Discussion Starter · #60 ·
It has been a lot of years since I did a no-kidding quarter mile run. The last car I drag raced was a 67 Oldsmobile 442 that I had great fun modifying and rebuilding over several years then converting back to a street configuration and driving it until it literally fell apart in the mid 80's.

Optimizing the hole shot with Sally would take significant practice to learn the throttle setting that will just keep the rear wheels hooked up and I am not willing to do a bunch of clutch-torturing runs. I will do a couple just to get a feel but with the ability to break the rear wheels away at full throttle, I'll bet getting a good velocity slope is about all I will be able to do. Second and third gears are simply hang on and keep it straight, so I will be able to get a good accel profile for each gear. It probably won't happen until I get back south.
 
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