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The reason I asked is because all of the Gen II GTMs that we've built here with the factory FFR fiberglass vent inserts installed have all run pretty hot.....
 

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Discussion Starter #22 (Edited)
I’ve heard that’s the case. The outside coolant pipe routing adds a lot of volume and also dissipates heat in a relatively open environment vs the tunnel and may be part of the solution. Also I have the Setrab 25-row oil cooler. Will report back when temps hit 90-100 in the summer.
 

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Discussion Starter #23
Man I love this car, how it drives, Rock steady. Great dampers are truly key for uneven roads. And for those who didn’t already know this, the Kooks exhaust note is nothing short of glorious. I return home only thinking about when I will get a chance to go for another drive.

Lots of little stuff to do though for comfort, sealing little gaps, adding sound deadening in the right places, then splitter, diffuser and more camber for track duty. Lovely project. And she’s still in primer.

357322
 

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Discussion Starter #24
Shane, I forgot to mention on more thing: I have placed my radiator more flat (rear is higher than original position by ~2.5" and I have a curved aluminim guide seamlesly connecting from the bottom front of the radiator box to the back / bottom of the radiator in a nice wide curve shape.

The (unproven) theory I have is that the airflow now gets curved up and through the radiator as a flow, rather than hitting the radiator in shear and possible stalling in the back of the radiator box with potential aero chaos and pressure build up.. If there's resistance in the box it can of course go through the radiator however it has to fight new air coming in as well, basically just adding a more pressurized zone that in turn would make some air choose a path other than the grille inlet instead of into the grille.

If this theory is correct it'd mean there is more air flowing into the grille and up through the radiator and no stalled air or pressure build up except the resistance of the radiator fins. I imagined trying to flow water at high rate through the grille and out the hood to come up with something that'd make the best flow with least resistance, but CFD simulation would prove this right or totally wrong. Anyway, as mentioned before I will follow up when the summer comes around.
 

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Discussion Starter #26 (Edited)
359626


Long since I posted, and actively worked on the car apart from a few things:
Polycarbonate hatch "glass" - quick and dirty, too wavy so will do again
Headlight covers
Z51 brake rotor upgrade.
Borg lower control arm offset bushings (for more negative camber at the front).
Camera based rear view mirror
All LED lights incl DRL/turn indicators
Adjustable rear diffuser rods, the original angle is too step to generate good downforce/low drag

The big step came today though. Sacramento did decide that the car has to visit the BAR for a thorough smog exemption process (called SB100 in CA). After a lot of paperwork collection and virtual meetings and calls with the BAR, I finally got invited to an in person vehicle inspection. I can't thank Jack (cob427sc) enough, he originally built this GTM and helped provide testimonial of assembly and references to the yards that sold him the donor parts. Without the build history it would likely not have been possible to complete the CA registration. Today's lunch appointment at the BAR was supposed to be the last step but they took photos, checked that the car matched the paperwork from the virtual meetings. Then said "Now a manager has to review it. He'll call in a few days, and if not then you have to call us back."

Oh no another go around.... but believe it or not they called me only 2 hours later and said it's been approved. Great stuff. I still have to return for the actual label to get affixed in the engine bay but that should be it. A good excuse for another drive and the station is very close to my house.

With just below 100 degrees outside the cooling system seems fine, stays at 175-180 all the time. Got to sit at a few stop lights and it doesn't seem to cause any issues. I do need to properly pull vacuum and fill the AC though, only put a pressurized can on it when I reassembled the car and that seems to have proved it's leak free but it's (OBVIOUSLY) not as effective as it should be. Easy job on the To Do list.

Next up is side skirts, front splitter, some kind of door handles. I DO NOT LIKE POPPERS, to me it's a HUGE nuisance at a track day to have to go dig in the pocket for the remote every time I want to open a door, or if the window is open lean in and drag on the inside door handle. I want a proper way to grab and open the door. It's the first interaction with the car before you drive. It should feel solid. Maybe a cutout under the hips shape of the door and a push button that I can kill with a remote to lock the car. Also have a couple of low mileage 997 handles that feel superb but not sure how they'd look on the door. Also inside I want to switch to the interior door handles of a 997, or just the GT3 RS type straps. The semi flexing interior Corvette handles just don't do the solid driving characteristics justice. You can't have a rock solid car when driving and then when you touch it to get out, or get in, it's flimsy or annoying.

The car is performing very well. It is nice to work on comfort items for a bit, and it's soon time to get help to fix the body gaps and get it painted.

I worked out the engine items I discovered at the shakedown. It had a bad tune with torque limiter that depowered the car in every gear, and the coolant temp sensor wire was grounding to the block intermittently telling the motor sometimes it was at 278 deg F, which pulled crazy timing and made it run weak. With those items solved the car gained around 125hp on the dyno, feels quick, and the Kooks exhaust sounds absolutely glorious. Absolutely glorious! It made 330 rwhp on 91 pump gas which is nice and easy to drive with. Bone stock LS1 with the LS6 manifold and Kooks. I do have a 555rwhp LS7 ready to drop in sometime, but probably won't be until this fall or winter after enjoying the car this summer.

Loving this car more and more the less I need to do hard work on it, and the more I can just drive and play with it.
 

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Discussion Starter #27
I had more oppo in 95 deg temp to push the cooling system in day to day driving conditions. Already confirmed it to be great at the track. Did 2x40 min drive with a 25min stop and some parking movement inbetween, drives had lots of stop lights, idling, low speed. After that I just let it idle for 20 min. Needle lands at 191. Fans kick in, cools it, fans turn off. Then takes 1-3 minutes before fan kicks in again. Repeat. If it was 105 I don’t think it’s going to be much different. Plus cockpit doesn’t need much AC to stay cool. Bottom line; rear mount reservoir and outboard coolant pipes work just as great on a street car as a racecar.
 

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Discussion Starter #28
Installed the QRP swaybar kit today. Had to run it in fwd position bc the coolant side pipe solution takes up the spot the bar normally go into. Driving notes below.

359702
 

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Discussion Starter #29
I was debating w myself whether to install the swaybar or not. Balance was absolutely perfect on my track shakedown so adding front bar generally induces push which will require a rear bar or spring rate change. So why add weight, work, to create more work? The answer is, pictures! There was a lot of body roll visible from my track shakedown. And a lot of uneven tirewear from not enough camber combined with excessive bodyroll. Springs are hardcore already. So bar on to reduce roll (or sway).

Results: Insanely good steering response. Super 7 meets racecar. On top of that a more composed ride on uneven roads. The coupling of left/right took down bump steer by 70-80%, the steering wheel doesn’t jog left rig left right anxiously along some of the vineyards. I can just drive and hold it lightly on really uneven roads, before I had to keep the car actively from the ditch or oncoming unless the road was pretty smooth. Game changer. In regards to comfort, bumps that used to feel like extremely harsh impacts are now feeling a bit rounded, this is a known swaybar effect in OEM car development when it comes to ride tuning.

359703
 

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Discussion Starter #30
Still not painted but added splitter, and put on APR C7 wing stands that are slanted rearwards more. This generally results in less drag, better overall downforce. Did a number of under the body jobs too incl Z51 caliper brackets and rotors. Adds rotating mass but more rotor material is the wise choice since I have a cammed LS7 ready to drop in this winter, adding appr 200 rwhp. Looking forward to take it to another track day soon.

360208
 
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