The coolant cap has a rating of 140 kPa which is a bit higher than the Koyo radiator cap on Project S2000 that was rated at 127 kPa. Higher pressure raises the temperature at which coolant will boil.
Supposedly, to top off the coolant, it should reach the bottom of this blue tube when cold. It’s not easy to see exactly when that happens.
When the coolant is warm, it should reach the MAX line which is at the angled surface you see in the tube. This was after getting the car fully warmed up and taking the engine to redline a few times to really push the coolant around. Of course, be extremely careful when opening this cap after the car has been running. It looks like I over-filled just a bit. From what I’ve read, over-filling just causes coolant to leak out somewhere and onto the ground. I haven’t noticed a puddle anywhere underneath my car, so it must be right at the limit.
Overall, I’m very happy with the installation of the GT3 vent. I did a so-so job on installing the Radiator Grill Store center grill; maybe I’ll get around to making that neater someday. Oh yeah, I installed clear side markers after the head of design at work called me out for still having the yellow ones.
With the car at the stock 300hp power levels, I figure the stock thermal system is good to around an ambient temperature of 80F while maintaining my oil temperature limit of 240F/115C. With the protune with the COBB Accessport, I’m pushing about 35whp more than stock on my 93 octane cocktail made from 91 octane gas and Race Gas Concentrate additive. With the cooling upgrades, I’m going to see how the thermals stack up to the higher power and warmer ambient temperatures on track. And I’ll have more info on the Accessport to report.
11 comments
What a cool mod!
That’s not punny. You’re going to get punished by being sent to the punintentary.
Cool and rad. Nice article. I think I’ve accepted the fact that I will never be cool enough to understand Porsche life.
Just modding for more cooling for better track reliability like my other cars. Just happens Porsche has more factory parts to use!
Nice! I’m surprised you didn’t just buy the replica or OEM GT4 front bumper! You get the top vent, larger lower vent openings, and a more aggressive front splitter for maybe more front downforce. Plus you wouldn’t have had to hack up the stock front bumper. AFAIK, a GT4 front bump is pretty much a plug and play solution. Can’t wait to see even more progress on this build!
Maybe it’s just me but I would not want to put an aftermarket fiberglass bumper on a Porsche daily driven street car. An OEM GT4 bumper is pretty spendy. This is a nice compromise.
The reason for not doing a GT4 front end is that it would get destroyed around where I live. Lots of steep driveway entries in shopping plazas, gas stations, parking lots, etc. As it is, I scrape the air strake in front of the front tire every time I leave my complex. A couple people have done the full GT4 frontend conversion.
The center vent really looks factory – great job!
Great job and beautifully documented!
Fantastic final result.
It’ll be interesting to compare temperatures with a stock car with common “control” ambients and driving, at a track day.
I 100% agree with the perfect compromise of repurposing the stock bumper, on the grounds of cost and ground clearance. I have a 981 GT4 and conscious of the limited approach angle.
I live in the UK where local town councils instal traffic speed calming with “sleeping policemen”, which I negotiated at an angle and crab over.
Hotels in Europe tend to have underground car parks and on road trips I check if they are ok for low sports cars!
The 997 GT3 vent looks pretty good on the 718. But, why not just use the actual GT4 radiator kit instead of the GTS?
To do the GT4 center radiator right, either have to do the full GT4 front end conversion or make a custom center section to go from the base bumper opening geometry to the GT4 radiator. Neither are easy or low cost options.