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Asked my friend if I could share his screenshot from the event @ midO gridelife event towards end of summer. I believe this was the same one you were at, but if you can figure which cooling "set up" you were running, it can give you a nice comparison. He has stock radiator, AC condenser, oil cooler. His temps recorded were from a mid-afternoon run.
Asked my friend if I could share his screenshot from the event @ midO gridelife event towards end of summer. I believe this was the same one you were at, but if you can figure which cooling "set up" you were running, it can give you a nice comparison. He has stock radiator, AC condenser, oil cooler. His temps recorded were from a mid-afternoon run.
Mid O was Setup 2. I’m now on the last setup and it’s good enough that I’m going to leave it there. Most of the time it was running around at ~215oF with the last setup. That’s acceptable for me.
Oh, and the brake cooling ducts. I went back through my eBay purchase history and the person listing them doesn’t have them up anymore. I’ll DM you their username if you want to send a message to ask them.
I see the mishi setup recommended way to often and I wish more people would realize the the OEM shroud and fan is the best option without going to an extremely expensive SPAL setup.
Mid O was Setup 2. I’m now on the last setup and it’s good enough that I’m going to leave it there. Most of the time it was running around at ~215oF with the last setup. That’s acceptable for me.
Oh, and the brake cooling ducts. I went back through my eBay purchase history and the person listing them doesn’t have them up anymore. I’ll DM you their username if you want to send a message to ask them.
I’ve read about that delete many times but have not sat down to understand the reason behind it. I understand Nissan built that in to cool the oil in the lower bottom of engine (correct me if I’m wrong here). But what made you decide to delete that particular cooling system/line? Very curious
also thanks for your PM about the brake ducts. The user does not have it for sale anymore but I may PM him just to see. I haven't had any brake cooling issues yet for me to think about cooling the brakes off due to fad/pedal consistency.
A friend and I had a thought about your cooling issue and we thought it could be the coolant system not properly bled; still containing air pockets that does not let the system work efficiently.
I’ve read about that delete many times but have not sat down to understand the reason behind it. I understand Nissan built that in to cool the oil in the lower bottom of engine (correct me if I’m wrong here). But what made you decide to delete that particular cooling system/line? Very curious
also thanks for your PM about the brake ducts. The user does not have it for sale anymore but I may PM him just to see. I haven't had any brake cooling issues yet for me to think about cooling the brakes off due to fad/pedal consistency.
A friend and I had a thought about your cooling issue and we thought it could be the coolant system not properly bled; still containing air pockets that does not let the system work efficiently.
-T
The factory heat exchanger is largely there for street applications. It helps get the oil to operating temperature more quickly, improving longevity of the engine. Coolant that gets to temp more quickly is circulated past oil entering and exiting the filter (primarily entering), heating the oil.
Once the engine is up to temp, there very marginal cooling benefits given engine oil on the street is usually some 10 oF warmer than the coolant, so heat transfers in the opposite direction.
But…
If you check the routing of the coolant for the factory heat exchanger, you’ll notice that it comes from the hot side of the system (exiting the back of the block) runs through the heat exchanger, and then straight back to the water pump. It doesn’t ever run that flow of coolant through the radiator.
This leads to a lot of cross-talk (for lack of a better term) between the two fluids as a spike in one just heats the other and vice versa. Not ideal for an on-track application.
With all that said, my issues were exacerbated by dead/dying fans and then a bottleneck aftermarket shroud and garbage fans. Having titanium headers also contributes to high under-hood temps.
Nissan eventually deleted the heat exchanger with the HR and revised the coolant flow in the back of the block to get on top of any cooling it needed.
Comparing setup 1 and setup 4, there’s a pretty consistent 10-15 oF peak temp reduction by replacing the factory exchanger with an external, dedicated, oil cooler. The (eyeball) average temps dropped from ~230 to ~215.
About the system not being bled properly - I agree this is often a problem with the Z33, but I’ve got more than a decade of experience with this chassis and even more with racecars in general. It was properly bled. I appreciate the help though.
I’m happy with the setup as it is now, I’ll ceramic coat the headers and delete the AC condenser the next time the engine is out, sometime next winter I expect.
I never understood removing the heater/cooler either, it'll do both jobs albeit to a certain degree, the more efficient the cooling system the more it'll cool the oil.
a lot of people tend to believe that because the HR doesn't have it that it's not needed, but to each their own.
The factory heat exchanger is largely there for street applications. It helps get the oil to operating temperature more quickly, improving longevity of the engine. Coolant that gets to temp more quickly is circulated past oil entering and exiting the filter (primarily entering), heating the oil.
This makes a bit more sense to me now. Am I understanding this right: on street, oil temps are usually higher (only about 10F) than coolant. However, on track the coolant temps are a lot higher than oil temps, which would cause the oil temps to spike a bit with the oil warmer contributing some of that temp gain (safe to say most of the temp gain of oil temps due to that area?)
If I am not having any water temp or oil temp issues then I will leave it alone, if that is my basis for leaving the system still there is that reasonable? Am I missing out on another benefit? I usually am tracking in the NE region which is fairly cooler than other parts of the nation. I believe I've only been to 1 or 2 trackdays where temps were above 85F midday.
The coolant temps are controlled by the thermostat, once the engine is warmed up they should stay in the thermostat controlled range (180-210 F) on the street and on the track. If they are spiking beyond, the cooling system is not sufficient and the radiator should be upgraded. The oil temps are not thermostat controlled, so they will usually be lower on the street than they are on the track..On the street they will hover near coolant temps, on the track they will likely be significantly above coolant temps, depending on the setup they can range from 200 to 250F and beyond. So while on the street the heat exchanger offers minimal heat transfer in a warmed up car, on the track it still allows some heat transfer from oil to coolant and as long as the radiator can keep up it will provide additional cooling benefit. It's not significant comparing to an actual oil cooler, but it's something.
Just whilst you guys are chatting about cooling...
I noticed that after rebuilding my engine, and deleting the the oil cooler/warmer (and a couple of bypass lines), running a Koyorad with the Z1 'Pathfinder' mod, my coolant gets up to temp VERY quickly (we're talking a couple of mins to blow hot air in the cabin).
No coolant overheating on track though, oil temps around 125c (for my particular oil this is optimal), bit weird not really sure why.
Sorry for the mini-threadjack!
That makes sense. Without the heat exchanger your coolant will heat up quicker at the expense of your oil staying cold longer. So your toes are nice are toasty but your engine is experiencing additional wear and tear on cold startups :P
That makes sense. Without the heat exchanger your coolant will heat up quicker at the expense of your oil staying cold longer. So your toes are nice are toasty but your engine is experiencing additional wear and tear on cold startups :P
Well hopefully not wear and tear
I'll try and see how long it takes for the oil to get up to reasonable temp on the road (need to start a build thread tbh).
Most of the engine wear occurs on cold starts before the oil gets fully circulated. Cold oil is more viscous and takes longer to circulate than warm oil. By removing the heat exchanger you're extending the amount of time the oil remains cold and the amount of time it takes for the oil to fully circulate inside the engine. So some additional wear is occurring. Probably not significant on a track engine that will see 20k miles in it's lifetime. But on a street engine that might see 200k miles by all means it's significant additional wear that'll reduce the engine longevity in the long run.
Well ho-leee sugar! It's been a while gang. Why the delay? All the life stuff, winter stuff, pandemic stuff, relationship stuff, car stuff...you know...stuff.
So...Where were we? GkTech FUCAs had just been installed and the cooling package had been sorted out, right? Gridlife Midwest fest 2021 next up? Right.
I got back from a vacation to the Pacific time zone at midnight the night before driving into the Eastern time zone to get to Gridlife Midwest Fest. This is the big OG Gridlife main event with time attack, GLTC wheel-to-wheel, drift, and HPDE all packed in alongside a music festival, vendors, food trucks, and much late-night tomfoolery. Time attack starts on Thursday before most of the masses show up, so the track is open for us HPDE types to get in and get through tech before the rush on Friday morning when the rest of the sessions kick off. I was a zombie when I got there Thursday evening, but the car and I made it after time attack had wrapped up for the day. The Michigan Boys had saved me a spot with them right across from the tower and I got registered and the car through Tech Thursday night before heading to the BnB for the night.
This was my first time around Gingerman Raceway. It's a great track for HPDE. Super safe with the right mix of technical and high-thrill elements thrown in. With the increased camber and caster the front of the car was a revelation. I had a bit of a taste of how much better it was at the ABCC North test day a few weeks before, but Gingerman really brought out how solid the change was. My brake pedal consistency was still missing, but I was starting to identify that it was only firm-yet-futile when I jumped on the brakes near the redline, and that toe-heel blip would bring them in straight away...
Either way, it was a relaxing Friday of pounding around a new circuit. I set my best time of the weekend Friday before chasing it the rest of the weekend. It was only in the footage afterwards did a realize that on that lap I pointed by the FCP Euro GT3 cars that were giving ridealongs during the HPDE sessions. That's good for another -1.5 sec, right?! (lol) In any case, I was pretty content with my 1:50.something for my first time around there on nearly dead RT-660s.
Friday night got a bit out of hand as my partner was driving up from Chicago after work and would be arriving late, but moreover could be my DD! I had brought along some of Chicago's finest, Malort, to share with the crew. Suffice to say they were not fans (I actually like the stuff...). We took in some of the music and a small bonfire before my partner and I headed to our BnB for the night.
Saturday was great weather and some great GLTC racing with my HPDE sessions sprinkled in. I finally got my partner out on track to show off the fruits of my garage-bound labors. Was she impressed? More impressed in my commitment to the cause, I think! I was pushing hard on Saturday looking to better my time from Friday, but with all the drift action, high temps, dying tires, and this damnable brake pedal, improvement wasn't in the cards. We shut it down early on Saturday to get some good rest for the Sunday sessions and the drive back to Chi-town.
Sunday yielded only one session. I decided to bleed brakes after my first session and was surprised to find my front tires had started chunking on the outer shoulder. This had happened to my friend driving a time attack RX8 earlier in the weekend. Some combination of pounding into the end of the curb where the earth had been dug out, the high temps, and the end of tire life had exposed the belting in some areas. Deciding discretion was the better part of valor, I rotated the worst pair to the rear, aired up the rollers and headed for home.
Quick recap: The brake pedal had been inconsistent all season. There had been improvements with the maintenance work done throughout including: loads of fresh fluid, complete rebuild of the rear calipers. replacement of the front calipers. two sets of pads, and two sets of rotors.
At my last event of the year I finally clued into some of the nuance of the inconsistency - the pedal was very firm and mostly useless when I got on the brakes with the revs above ~5500-6000rpm.
So in a naturally aspirated car with big(ish) cams, what do we know about high rpm...well...intake vacuum is negligible. This was evidenced by the trouble I had with the plenum not pulling enough volume through the catch can to lower the crankcase pressure sufficiently to avoid blowing oil past the plug seals early in the season. Poor vacuum means poor assist, presenting as a firm but somewhat useless pedal. The fact that the brakes would come on strong after engaging the clutch and bliping during a downshift further lent credence to the lack of vacuum assist being the culprit. This tied into the inconsistency factor as well, basically tied to revs, but in a way that wasn't entirely predictable.
BUT WHY? ISN'T THERE A CHECK VALVE MEANT TO MAINTAIN VACUUM IN THE BOOSTER?!
I mean...there was...and I neglected to reinstall it when I installed silicone hoses...
Let that be a lesson to you, kids.
So a $10 check valve later, my brake pedal was consistent and content.
My check valve shame equivalent to forgetting to remove the lens cap out of the way...
WINTER PROJECT TIME
The week after getting back from Midwest Fest (September 2021) my diff that I ordered in March 2021 finally arrived! It's an OS Giken Superlock 1.5 unit. I was super excited for the diff as throughout the 2021 season the factory VLSD would overheat quickly during a session and would start behaving as an open differential. This was like some pseudo traction control, but the lack of drive off of corners was frustrating while the locking/unlocking as roll moment came off the car occasionally created harmonics in the rear suspension that would cause some mild bouncing (I was doing it before F1 made it cool :P).
To go with the new LSD, I picked up a 4.36 final drive. Yes, this would make the car near unbearable on the highway, but hopefully I only have one more season of that before it gets to hitch a ride. Making all my power up top due to the cams means I need all the short-gearing-torque-multiplication I can get. In addition to the final drive I grabbed all new stub axles, seals, bearings, a finned cover and a diff brace.
I dropped all the bits off at a local driveline shop that came recommended by a local shop that builds drag-racing Supras. While my diff was getting built I re-powdercoated the Bell's Raceworks brace to something more up my street.
With the diff back I did a quick check of the pattern, slapped on the new cover, and got it in the car.
In parallel with some of the fall activities, I decided to COMMIT TO THE LIFESTYLE and do some trimming of the bodywork. I cleared this with the Gridlife technical staff and got out the cutoff wheel and went to town. @2TH PWR was the inspiration for the cut. I figured all Canadian Z's (even expat ones) need cut bumpers. Because the car is street driven it's getting a replacement rear crash bar. I played with the CNC plasma at my local makerspace to make some baseplates for a custom rear bar that I booger welded together in the garage before having it powedercoated in the spring. This can come off at the track, or can be used as a rear tow hook. The lack of weight on the back of the car is becoming a problem...
Somehwere in there i passed smog with the car. Yes, it has cats. Yes, it blows clean. No, the EVAP is not defeated, it legit passes smog.
A bit deeper into the winter I started working on a custom fender vent solution that would keep the car looking half nice while still evacuating the rear portion of the front wheel wells. I started by laying out some tape to get some measurements and a general shape. I printed a quick prototype that was swiftly abandoned in favor of Ver 2.0 once I actually got to cutting metal. This is the version on the car right now, but there will be one more version that ultimately follows the contours of the fender more closely.
The car is still a heavy gal, so she went on a bit of a diet over the winter. First the stereo is gone (except the head unit, I have plans for that later), along with the entire structure behind the seats. If the 3200lb sedan guys get to pull out their entire rear seats when they add a roll bar, I'm pulling the 25lbs of crap back there out of my 3400lb coupe in exchange for my roll bar. I mean, it DID interfere with installation of my roll bar...cough...cough...
I also sprung for some two-piece rotors, because, racecar...and a claimed 15lbs per axle. It's more like 15lbs across both axles, but saving any of the worst kind of weight (unspring and rotating) is positive.
The big weight savings was the addition of a Radium fuel hanger surge tank. I was getting fuel cuts in some long right-hand corners at 2/3 tank last year. This should let me run at as low as 5 gal for the session and doesn't require anything too complicated on the outside. SOME NOTES: 1. Radium missed a step in their instructions, before you try and fish the hoses around, just drop the rear subframe. Trust me, it's better that way. 2. The flat mating face of the radium unit means that getting it to seal against a 16 year old tank flange is tricky, even with new OE gaskets. Dress the OE gasket in some fuel-safe flange sealant and save yourself trying to rectify that while huffing 93 and balancing a surge tank above a full tank of fuel 12 hours before your alignment appointment...don't ask me how I know.
As part of prepping for the season the reman brakes on the front got rebuilt with OE Brembo seals and a Z1 crossover o-ring. New bolts were used to mate the halves. Yes, I split the halves. Don't @ me.
Factory aero is permitted, so I got this OEM rep spoiler to match the carbon hatch and stuck it on. I'm also a child of the first Fast and Furious, so I got some cheapo carbon mirror covers. Go ahead, judge me. You thought underglow was cool at one point, I know you did...
Oh, and yea...I WRAPPED THE FREAKING CAR. I did a lot of it panel by panel in my apartment on a bodywork stand. Was it hard? I mean kind of...The Z33 is a good chassis to learn on because it has mostly flat panels. That said, the front bumper was tricky. Is it perfect? HA! no, it's not perfect, but it's very much good enough for a race car. I sanded a lot of the surfaces and did some spot glazing and rust repair before wrapping. She's 17 years old and a four-season warrior. I'm lucky there's panels left to wrap. I've had the wrap sitting the house for over a year and am pretty darn pleased with how it came out. It is spot on my favorite color.
New tires arrived and were mounted up. I replaced my faulty TPMS unit and installed a momentary pushbutton under the passenger dash to make resetting the TPMS super easy. It's nice to have pressures on the dash at the end of a session, even if the system is NOT happy when you leave the pits at 23-25psi cold.
Also, I'm driving in Street Class time attack with Gridlife for 2022! I'll be running the midwest rounds with maybe a trip to Kansas in the fall. The Gridlife office isn't too far from me so I was able to snag my series decals to get them on with my BRE 240Z-inspired livery. You also may note the fiberglass side skirts. The factory ones were super chewed up and these were cheaper than secondary market factory replacements in equally garbage condition. Cheaper for good reason...they're trash. Absolute trash. Correct in exactly 0 dimensions. BUT, they're much lighter now that I've cut 60% of them away to even get them on the car...
11-13-2021, 03:57 PM
