Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum - View Single Post - Blue Bayou S13 - VQ30DE Endurance Build (Tons of pics and video!)

knate · 01-06-2021, 08:01 PM

We only had a few weeks to get ready for the next race, and knew we had some overheating issues. I had added water pressure sensors to our datalogger, and in reviewing our datalogs I found where the car was venting pressure during a pitstop. I chalked this up to a bad radiator cap, since during the race we had seen the pressure disappear, then build back up again after the engine had cooled down. We replaced the water pump, thermostat, and radiator cap.

I also found myself completely exhausted and soaked with sweat getting out of the car in the last unexpectedly hot race (for the NW), so I went after building a cool suit cooler. Following some other directions online, I put together a cheap cooler using an Engel cooler, bilge pump, and a bilge timer.

Here it is attached in the car:

And here I am quite proud of my new Cool Shirt:

Until I realized the shirt was designed for the metal fittings, and I had the plastic fittings and it didn't clip in..

This groove was too narrow:

Mr. Generic Dremel to the rescue..

After being trimmed a bit, the fitting worked perfectly.

With that cleaned up we were ready for our race at the Ridge! Well, at least we thought we were.. I meant to get a warning light for the temperature gauge, but that didn't happen in time.

Rain at the Ridge (8/30/2014) - 4.5 hours - Ridge Motorsports Park:

I head out in the car during the yellow flag, but immediately find that the defrost is not working. I dive in the pits, and luckily my dad is able to quickly find a loose connection and my defrost is going again. There is massive spray everywhere and visibility is terrible, but the Ridge has relatively new pavement, and is much better than PIR to drive in the rain. I start in 36th place and start making my way forward in the field. The high horsepower cars are really struggling to put power down, so we really have just enough power for these conditions. I make it up to 11th place, then pit for my dad's turn with a best lap of 2:23.

My dad is out there and gets tagged in the back at the bottom of the hill. He manages to steer out of it without too much issue and continues on. By the time he pits, it's still wet and he has gotten us up to 6th place.

Since it's just the two of us at this race, I get back in the car and there is something wrong with the power. The car really seems to struggle to accelerate on the top end and is just not its usual self. I think it may be something with the knock sensor and the ecu pulling timing. The best lap I can muster is 5 seconds slower than my first sesssion! Luckily with all the rain this is less of a hit than it would normally be, so we manage to pull home a 4th place finish.

Drying up.. (8/30/2014) - 4.5 hours - Ridge Motorsports Park:

The ECU was showing a knock sensor code, so I dummy out the knock sensor with a resistor in hopes of fixing the power. I set out in the car for our second race, and it's starting to dry up. With the track drying up, I am reminded that the Ridge is definitely a "horsepower track". There are many long acceleration zones, and the 1/2 mile long front straight is preceded by a very slow corner.. so it's really a drag race.

The car is still down on power and I am getting killed on the straight stretch. I manage a 2:17, but this is not going to cut it with the leaders having ran a 2:04. I'm in 8th but since we have a few more races coming up, I decide to pull in the pits and we do a quick swap of the ECU. Success! We are back down to 36th place but the car now pulls like it used to, and I immediately knock 6 seconds off my lap time getting down to a 2:11. This is still not enough to win a race, but with our 7 minute pit stop to swap the ECU we are out of the running for a podium anyway. At least the car is working, we still have more races. The car works great for the rest of my stint. Temps are holding perfectly and power is OK. I'm still left wishing for power every time I'm near one of the V8 Mustangs, or the BMWs, or V6 anything..

I pull into the pits, we top off with oil (like we do on every pit stop), and my dad gets in. The track now dries up completely, and we are getting dusted by every car with more power than us. Which is most cars. When my dad pulls into the pits, he says that the power just doesn't quite seem as good as it used to, and that it doesn't pull past 5500 as hard as it used to. While I am exiting the pits, multiple tents get blasted over the pit wall and into the hot pits! The wind is really gusting, although it is dry out.

A few laps into my driving stint, I see the temperature start climbing. I radio in that I'm getting to 200F, where the temperature had been sitting rock solid at 180F. Just a few corners later the temperature starts to rocket up and I cruise it into the cold pits for the car to cool down. We discuss thermostat and other possibilites, then I loop around the pits slowly and the temps drop. I decide to take it back out on the track to see what happens. Just like at Portland.. I start pushing on the car again and temps are still right at 180F.. how strange, and frustrating. That pit stop dropped me from 20th to 29th. I get back to 25th with a fastest lap of a 2:08 before the car decides to randomly overheat and I pull into the pits to end our race for the day.

We swap in a known good fuel rail (complete with good injectors) as it seems like our fuel mileage is a little too good.

Please don't overheat.. (8/31/2014) - 9 hours - Ridge Motorsports Park:

My dad heads out on course for the first stint and sets a 2:07 lap time! He says the car is working good and feels great. My dad is still out on course and after about an hour we radio my dad to ask him how much fuel he has left and he says he has 3/4 tank. What?? That cannot be right.. fuel gauge must have quit working.. The temps are holding rock solid and the car is working good. My dad pulls into the pits in 9th place on lap 44. We can't even get two fuel jugs into the car... how is this fuel mileage possible?

I head out in the car and within two laps.. the car has decided it's time to overheat. I pull into the cold pits and let the engine start cooling down. At this point we have realized that our issues are serious enough that the easy fixes have not helped, and we likely have an issue with the headgasket. That's not something we are going to fix in the pits at a race track (I know many of you have done that, but we are not prepared and motivated enough to do that). We figure we will run as hard as we can while we can, then if it overheats, let it cool down, and try for more later.

This was really a turning point for our weekend. We had started getting really focused on trying to get onto the podium, and to some degree seemed like fun was equal to doing well in the race. Having problems meant frustration. However once we knew there was no hope for a podium and we would just learn and have some fun runs here and there it changed everything. We were now hanging out with family and friends at a race track, with a car that would at least last for a few laps, so if one of us felt like going out, we could. If we felt like hanging out in the pits, we could.

We pulled the spark plugs, and they are WHITE! This confirms that we were running super lean with the other fuel rail, so that comes right back out and the original one goes in. This is super strange, as this was a known working spare..

I head out on track.. and the car overheats on me within a few laps and I pull in. More time to hang out with family and friends! I start chatting with Paul Newman's Revenge, who also drive a 240SX, and they are wondering if I would drive their car to see how it feels compared to our car. Their car has a full 300ZX brake system with custom dual master cylinder and significantly stiffer springs than our factory cut springs. Hey, this is cool, normally I would be too focused on our own race to jump in other people's cars.

I get in their car during the next pit stop, but I sit for an extra long stop as their rear pads were worn out and they had to swap them. What they forgot to mention, is that they had Autozone pads in the back before, and were now switching to Hawk Blues. The bias adjuster doesn't work anymore, because the system requires so much leg pressure to work that the balance bar is bent. The Kirkey seat feels like it is straight up, and is definitely an awkward position for me.

I head out of the pits, and immediately notice the clutch pedal has a lot of movement side-to-side. As I shift from 1st to 2nd, I accidentally slip the clutch a bit. Oof, I never have this issue in our car, the engagement point seems way too high. Luckily it's yellow when I head out onto the track, but when I step on the brake pedal it just feels like a rock.. and I'm not really slowing down. I start standing on the pedal for all I am worth.. and the car starts slowing down some. Ouch, this is going to be a lot of getting used to! I start to get a little bit of a feel for it, and start pushing the car a little harder, then putting the 150+ lbs of leg force into the pedal for the braking zones. Their engine feels pretty strong (same KA24DE but with a bigger exhaust), but the shocks are terrible. The springs are extremely stiff but paired with stock shocks, so it's as if they don't exist. The car skips and hops in corners that our car has no issue with at all.

My dad had decided to jump in Blue Bayou and try to chase me down. As he was closing down on me, I see our old rival Son of Andre come on track and I decide to see how well I can hang with them. Despite the bouncy suspension and brakes that require way too much leg force I am hanging on behind Son of Andre, and my dad is catching me from behind. I head into the sharp left-hander turn 13, and brake hard. As I crest the hill I am trail braking and there is a slight bump and the back end snaps out. I had been drifting at this track in my personal car a few months prior, no big deal, just spin the wheel to catch the slide... except with no shocks and rock hard springs... the back end just won't grip up. I am at full lock and end up in the world's slowest rotation going nose first into the gravel off to the left. And I'm stuck. I have never been stuck on the side of the track before during a race, and now I did it in someone else's car. How embarassing! The only small consolation was.. most people don't know it was me. After getting pulled out of the gravel I pull into the pits ashamed and give my report on how the car felt. Thanks for the opportunity to drive it though!

Tech Tip #11: If a car works OK from the factory, make small tweaks, don't start from scratch! Our 240SX with lengthened control arms (for more camber) and cut springs is SO much easier to drive than the one with custom steering column, custom race car brakes, custom suspension setup, etc.

We end up 38th in this forgettable race.

Ok, we know you are going to overheat.. (9/1/2014) - 4 hours - Ridge Motorsports Park:

I head out first and run a bunch of 2:04s, setting our fastest lap at the Ridge! I get up into 6th place before on lap 17 the car decides it's time for me to hang out with friends in the pits. We have a blast catching up with other teams and treating the day more like a track day. We finish a forgettable 28th place but have lots of fun in the process.

Tech Tip #13: Don't take things so seriously that you forget to have fun regardless of the outcome!

Now for our fuel issue.. this was a bit of a head scratcher. We ordered new fuel injectors.. and those also came up as super lean. We finally figured out that the injectors that came with our mystery engine were actually bigger than factory injectors, and our fuel pump was starting to fail. Since the fuel pump had started failing at the same time the bigger injectors went in... it actually balanced out and we won a race with that setup! With a new fuel pump and new injectors, everything was good. We also bought an Air/Fuel ratio gauge so we could catch these kinds of issues in the future.

We also found corrosion on the ECU pins for the knock sensor and believe that is why it was triggering for phantom knock even with the dummy resistor. I believe our ECU was mounted too low in the car and water was able to splash up there.

Video overview of the weekend:

01-06-2021, 08:01 PM	#10
knate Leaky Injector Join Date: Feb 2005 Location: Washington Posts: 138 Trader Rating: (0)	We only had a few weeks to get ready for the next race, and knew we had some overheating issues. I had added water pressure sensors to our datalogger, and in reviewing our datalogs I found where the car was venting pressure during a pitstop. I chalked this up to a bad radiator cap, since during the race we had seen the pressure disappear, then build back up again after the engine had cooled down. We replaced the water pump, thermostat, and radiator cap. I also found myself completely exhausted and soaked with sweat getting out of the car in the last unexpectedly hot race (for the NW), so I went after building a cool suit cooler. Following some other directions online, I put together a cheap cooler using an Engel cooler, bilge pump, and a bilge timer. Here it is attached in the car: And here I am quite proud of my new Cool Shirt: Until I realized the shirt was designed for the metal fittings, and I had the plastic fittings and it didn't clip in.. This groove was too narrow: Mr. Generic Dremel to the rescue.. After being trimmed a bit, the fitting worked perfectly. With that cleaned up we were ready for our race at the Ridge! Well, at least we thought we were.. I meant to get a warning light for the temperature gauge, but that didn't happen in time. Rain at the Ridge (8/30/2014) - 4.5 hours - Ridge Motorsports Park: I head out in the car during the yellow flag, but immediately find that the defrost is not working. I dive in the pits, and luckily my dad is able to quickly find a loose connection and my defrost is going again. There is massive spray everywhere and visibility is terrible, but the Ridge has relatively new pavement, and is much better than PIR to drive in the rain. I start in 36th place and start making my way forward in the field. The high horsepower cars are really struggling to put power down, so we really have just enough power for these conditions. I make it up to 11th place, then pit for my dad's turn with a best lap of 2:23. My dad is out there and gets tagged in the back at the bottom of the hill. He manages to steer out of it without too much issue and continues on. By the time he pits, it's still wet and he has gotten us up to 6th place. Since it's just the two of us at this race, I get back in the car and there is something wrong with the power. The car really seems to struggle to accelerate on the top end and is just not its usual self. I think it may be something with the knock sensor and the ecu pulling timing. The best lap I can muster is 5 seconds slower than my first sesssion! Luckily with all the rain this is less of a hit than it would normally be, so we manage to pull home a 4th place finish. Drying up.. (8/30/2014) - 4.5 hours - Ridge Motorsports Park: The ECU was showing a knock sensor code, so I dummy out the knock sensor with a resistor in hopes of fixing the power. I set out in the car for our second race, and it's starting to dry up. With the track drying up, I am reminded that the Ridge is definitely a "horsepower track". There are many long acceleration zones, and the 1/2 mile long front straight is preceded by a very slow corner.. so it's really a drag race. The car is still down on power and I am getting killed on the straight stretch. I manage a 2:17, but this is not going to cut it with the leaders having ran a 2:04. I'm in 8th but since we have a few more races coming up, I decide to pull in the pits and we do a quick swap of the ECU. Success! We are back down to 36th place but the car now pulls like it used to, and I immediately knock 6 seconds off my lap time getting down to a 2:11. This is still not enough to win a race, but with our 7 minute pit stop to swap the ECU we are out of the running for a podium anyway. At least the car is working, we still have more races. The car works great for the rest of my stint. Temps are holding perfectly and power is OK. I'm still left wishing for power every time I'm near one of the V8 Mustangs, or the BMWs, or V6 anything.. I pull into the pits, we top off with oil (like we do on every pit stop), and my dad gets in. The track now dries up completely, and we are getting dusted by every car with more power than us. Which is most cars. When my dad pulls into the pits, he says that the power just doesn't quite seem as good as it used to, and that it doesn't pull past 5500 as hard as it used to. While I am exiting the pits, multiple tents get blasted over the pit wall and into the hot pits! The wind is really gusting, although it is dry out. A few laps into my driving stint, I see the temperature start climbing. I radio in that I'm getting to 200F, where the temperature had been sitting rock solid at 180F. Just a few corners later the temperature starts to rocket up and I cruise it into the cold pits for the car to cool down. We discuss thermostat and other possibilites, then I loop around the pits slowly and the temps drop. I decide to take it back out on the track to see what happens. Just like at Portland.. I start pushing on the car again and temps are still right at 180F.. how strange, and frustrating. That pit stop dropped me from 20th to 29th. I get back to 25th with a fastest lap of a 2:08 before the car decides to randomly overheat and I pull into the pits to end our race for the day. We swap in a known good fuel rail (complete with good injectors) as it seems like our fuel mileage is a little too good. Please don't overheat.. (8/31/2014) - 9 hours - Ridge Motorsports Park: My dad heads out on course for the first stint and sets a 2:07 lap time! He says the car is working good and feels great. My dad is still out on course and after about an hour we radio my dad to ask him how much fuel he has left and he says he has 3/4 tank. What?? That cannot be right.. fuel gauge must have quit working.. The temps are holding rock solid and the car is working good. My dad pulls into the pits in 9th place on lap 44. We can't even get two fuel jugs into the car... how is this fuel mileage possible? I head out in the car and within two laps.. the car has decided it's time to overheat. I pull into the cold pits and let the engine start cooling down. At this point we have realized that our issues are serious enough that the easy fixes have not helped, and we likely have an issue with the headgasket. That's not something we are going to fix in the pits at a race track (I know many of you have done that, but we are not prepared and motivated enough to do that). We figure we will run as hard as we can while we can, then if it overheats, let it cool down, and try for more later. This was really a turning point for our weekend. We had started getting really focused on trying to get onto the podium, and to some degree seemed like fun was equal to doing well in the race. Having problems meant frustration. However once we knew there was no hope for a podium and we would just learn and have some fun runs here and there it changed everything. We were now hanging out with family and friends at a race track, with a car that would at least last for a few laps, so if one of us felt like going out, we could. If we felt like hanging out in the pits, we could. We pulled the spark plugs, and they are WHITE! This confirms that we were running super lean with the other fuel rail, so that comes right back out and the original one goes in. This is super strange, as this was a known working spare.. I head out on track.. and the car overheats on me within a few laps and I pull in. More time to hang out with family and friends! I start chatting with Paul Newman's Revenge, who also drive a 240SX, and they are wondering if I would drive their car to see how it feels compared to our car. Their car has a full 300ZX brake system with custom dual master cylinder and significantly stiffer springs than our factory cut springs. Hey, this is cool, normally I would be too focused on our own race to jump in other people's cars. I get in their car during the next pit stop, but I sit for an extra long stop as their rear pads were worn out and they had to swap them. What they forgot to mention, is that they had Autozone pads in the back before, and were now switching to Hawk Blues. The bias adjuster doesn't work anymore, because the system requires so much leg pressure to work that the balance bar is bent. The Kirkey seat feels like it is straight up, and is definitely an awkward position for me. I head out of the pits, and immediately notice the clutch pedal has a lot of movement side-to-side. As I shift from 1st to 2nd, I accidentally slip the clutch a bit. Oof, I never have this issue in our car, the engagement point seems way too high. Luckily it's yellow when I head out onto the track, but when I step on the brake pedal it just feels like a rock.. and I'm not really slowing down. I start standing on the pedal for all I am worth.. and the car starts slowing down some. Ouch, this is going to be a lot of getting used to! I start to get a little bit of a feel for it, and start pushing the car a little harder, then putting the 150+ lbs of leg force into the pedal for the braking zones. Their engine feels pretty strong (same KA24DE but with a bigger exhaust), but the shocks are terrible. The springs are extremely stiff but paired with stock shocks, so it's as if they don't exist. The car skips and hops in corners that our car has no issue with at all. My dad had decided to jump in Blue Bayou and try to chase me down. As he was closing down on me, I see our old rival Son of Andre come on track and I decide to see how well I can hang with them. Despite the bouncy suspension and brakes that require way too much leg force I am hanging on behind Son of Andre, and my dad is catching me from behind. I head into the sharp left-hander turn 13, and brake hard. As I crest the hill I am trail braking and there is a slight bump and the back end snaps out. I had been drifting at this track in my personal car a few months prior, no big deal, just spin the wheel to catch the slide... except with no shocks and rock hard springs... the back end just won't grip up. I am at full lock and end up in the world's slowest rotation going nose first into the gravel off to the left. And I'm stuck. I have never been stuck on the side of the track before during a race, and now I did it in someone else's car. How embarassing! The only small consolation was.. most people don't know it was me. After getting pulled out of the gravel I pull into the pits ashamed and give my report on how the car felt. Thanks for the opportunity to drive it though! Tech Tip #11: If a car works OK from the factory, make small tweaks, don't start from scratch! Our 240SX with lengthened control arms (for more camber) and cut springs is SO much easier to drive than the one with custom steering column, custom race car brakes, custom suspension setup, etc. We end up 38th in this forgettable race. Ok, we know you are going to overheat.. (9/1/2014) - 4 hours - Ridge Motorsports Park: I head out first and run a bunch of 2:04s, setting our fastest lap at the Ridge! I get up into 6th place before on lap 17 the car decides it's time for me to hang out with friends in the pits. We have a blast catching up with other teams and treating the day more like a track day. We finish a forgettable 28th place but have lots of fun in the process. Tech Tip #13: Don't take things so seriously that you forget to have fun regardless of the outcome! Now for our fuel issue.. this was a bit of a head scratcher. We ordered new fuel injectors.. and those also came up as super lean. We finally figured out that the injectors that came with our mystery engine were actually bigger than factory injectors, and our fuel pump was starting to fail. Since the fuel pump had started failing at the same time the bigger injectors went in... it actually balanced out and we won a race with that setup! With a new fuel pump and new injectors, everything was good. We also bought an Air/Fuel ratio gauge so we could catch these kinds of issues in the future. We also found corrosion on the ECU pins for the knock sensor and believe that is why it was triggering for phantom knock even with the dummy resistor. I believe our ECU was mounted too low in the car and water was able to splash up there. Video overview of the weekend: __________________ Blue Bayou Youtube Channel Facebook Last edited by knate; 04-18-2021 at 01:29 AM..