When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Sorry to bother you guys with more dumb questions, but I can't find much help on this car so far as I am not racing with POC or PCA just yet. Anyway I have a few more questions after another race.
1. The car is experiencing some fuel starvation on right turns. The car never had it prior to this weekend. I was getting it despite running with 4-5 more gallons than I did in the past races. Did I break something while I ran the tank low? I ran other tracks fine, down to much lower position.
2. I really want to put a coolant pressure gauge on my car as I am paranoid about everything. I am trying to avoid splicing the upper radiator hose as it is another source for leaks and I don't like how you can only get to that with the bumper off. Anyway since the system is under pressure, can I remove one of the hose for the coolant tank and run a barb and use a new hose to connect them? I am thinking about the one above the drain line since it is bigger. I don't want to Tee it as it is harder to just disconnect it.
3. How long do you guys get with the Toyo RR? Even though my tires are 8 days old and they are not at their prime obviously, yet they can usually come through in qualifying and drop 2-3 laps before falling off. Yet the same tires are a disaster in the race. I can pace at a decent clip the first 1/3 of the race, then a 2 sec drop off for the next 1/3 and then really far off the last 1/3. Did I overheat the rear tires or did it have something to do with the way they act as they age. It happened the last time I ran these 4 days old tires too. Or did I screw up on their pressure? I run the mid 20s in the front and low 30s in the back.
4. What is the normal water temp, oil temp and trans temp when racing?
My car has a coolant pressure sensor which is a brass angle fitting drilled/tapped into the coolant gallery cover at the left rear of the engine, with a short stainless braided line running to the sensor pot nearby. I have a Motec C127 dash that reads the coolant pressure, but you could read it with anything from this pickup point. It is usually around 0.5-0.7 BAR at say 3500 RPM. Sorry I just looked and I don't have a good photo showing this area.
My car has a coolant pressure sensor which is a brass angle fitting drilled/tapped into the coolant gallery cover at the left rear of the engine, with a short stainless braided line running to the sensor pot nearby. I have a Motec C127 dash that reads the coolant pressure, but you could read it with anything from this pickup point. It is usually around 0.5-0.7 BAR at say 3500 RPM. Sorry I just looked and I don't have a good photo showing this area.
Are those tire pressures cold or hot? If hot, mid-20's is way to low.
Hot temps very by driver preference, but I know of racers that run as low as 30 and as high as 39. I don't know of anyone that runs a split pressure of 5 psi front to rear, 2-3 yes for some.
They were both cold psi but I can see the possibility of running higher rear psi after my recent struggle in the race. I am getting some tpms sensors and possibly temp sensors to help with car setup. Overall it was a good test run, my qualifying pace isn’t bad but I need to improve on my racing.
They were both cold psi but I can see the possibility of running higher rear psi after my recent struggle in the race. I am getting some tpms sensors and possibly temp sensors to help with car setup. Overall it was a good test run, my qualifying pace isn’t bad but I need to improve on my racing.
You really need to be measuring hot pressures and then learning where to set cold pressures to achieve your hot pressure goal. On most days I see around a 7-9 psi increase from cold to hot.
Last year was my first season running RR's, on the advice of a top ranked SPB vet he suggested 35 hot all around and added that some drivers even like them up to 38. I ran them at 35 all year and was very happy, seemed consistent and predictable even when they creeped past 35. Initial cold pressures were usually around 26 depending on ambient and track temp.
You really need to be measuring hot pressures and then learning where to set cold pressures to achieve your hot pressure goal. On most days I see around a 7-9 psi increase from cold to hot.
You can get that done in one practice session. Even at the pro level we don't monitor temps or pressures on data. However, I do recommend a good data setup for driver improvement. I will be at several PCA events this year coaching, let me know if I can help.
More importantly you’ve actually discovered/felt tire fall off, which happens on tires with more heat cycles. They will be great for a few laps and then fall off. So they work for qual but not for a race. Normal and not related to tire pressure at all.
Originally Posted by coss1600
it’s cheap compare to trailering to multiple track days.
__________________ Todd Lamb
Atlanta Speedwerks www.ATLspeedwerks.com
Porsche repairs, servicing, and upgrades / Certified IMS installer / PDK repair experts
Over 150 PDK's repaired and counting: https://youtu.be/m54P_zisEcI
many races don’t have practice, I am just trying to get the car dial in before I join a more competitive event. Yes I look forward to meeting with many of you guys
agree on the tire drop off, but I would love to see the tire pressure reading on lap 3 vs lap 13 to see if the temp or psi had any impact on it. I recall the only two times this drop off didn’t happen was an event where I raced with new tires and an event where I was in a wheel to wheel battle the entire race. I don’t know if I just fought through it or the tires were newer then.
since my race wasn’t a competitive event, as soon as I sense the car was dropping off. I was driving a lot more cautiously. My qual time was about 2 sec quicker
Originally Posted by toddlamb
You can get that done in one practice session. Even at the pro level we don't monitor temps or pressures on data. However, I do recommend a good data setup for driver improvement. I will be at several PCA events this year coaching, let me know if I can help.
More importantly you’ve actually discovered/felt tire fall off, which happens on tires with more heat cycles. They will be great for a few laps and then fall off. So they work for qual but not for a race. Normal and not related to tire pressure at all.
Then do it in a race session - the point being all you need is a tire gauge and a pen/paper to figure tire pressures out in one session. Don't over think it - that's your worst enemy in racing.
It is already a known fact that tires will drop off during a race, and especially so with more heat cycles. You don't need to spend any money to reconfirm this. However if times are falling off 2+ sec per lap with a Toyo RR that's a driver issue, not a tire issue.
Fuel starvation - possible that the fuel pump has become dislodged from the mount in the tank. The tabs break off.
Then do it in a race session - the point being all you need is a tire gauge and a pen/paper to figure tire pressures out in one session. Don't over think it - that's your worst enemy in racing.
It is already a known fact that tires will drop off during a race, and especially so with more heat cycles. You don't need to spend any money to reconfirm this. However if times are falling off 2+ sec per lap with a Toyo RR that's a driver issue, not a tire issue.
Fuel starvation - possible that the fuel pump has become dislodged from the mount in the tank. The tabs break off.
What Todd said in all respects.
Don't nerd out on the data, first drive the car and figure out how to use all the tire that is available at any given time. Flying is a good guide: Aviate, navigate, communicate - in that order.
#paralysisanalysis
(also check/replace your fuel filter while you're at it, but not while driving)
Just my 2 cents, if you want to be competitive, you will save yourself a lot of time and money by hooking up with a coach and/or track support team that knows SPB’s. Todd is definitely one that can help. I didn’t see where you are from, but if you are in Texas there are a ton of local people too that are kinda good (being facetious) at SPB’s.
There are about a million questions you haven’t asked yet that they can help you with too which will be much cheaper/faster than you doing it on your own (shock settings, ride height, sway bars, brake pads, rotors, sweet spot for RR’s, qualifying v. Race tire strategy, etc).
For what it’s worth, the best advice I ever received was, “if you are ever comfortable in a SPB, you are doing it wrong”.
if you don’t care to be competitive, no issues with just going and having fun while being safe and enjoying the company. It’s a great class with a lot of great people.
02-28-2022, 03:54 AM
more newbie spec boxster questions
