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I'm with Option. Anything's better than the gaping hole under the front end and you've had a learning experience now if you end up doing another iteration! Better to play around with it now than during Summer once it's already hot.
Also, yeah, big performance gains to be had even just by running a full undertray. I couldn't believe how much cooler my car ran and how much better it handled at high speed just by installing a full plywood undertray.
I knew my exhaust wasn't ideal for performance, but I'd forgotten how small it is. I think Curly was on to something with the exhaust being a restriction.
I didn't pull the exhaust and collect any data, but if you look at the photo below you should be able to figure out where the restriction might be.
So lets see... 2.5 inch downpipe into a 2 inch section with a Cat. An unused O2 Sensor to fill the bung, and then a slip joint into a 2.25 or 2.5 inch section. Further back it's a bit better, with the axle back seeming to be 2.25 to 2.5.
Regardless, some searching around the internet indicates that a 2" pipe would support somewhere in the range of 150-200 horsepower, which is right where I'm at.
I talked to a guy I autocross with who runs a muffler shop, but it sounds like he mostly does smaller patch work and mufflers. It also sounds like he doesn't want the car to show up in his shop with a Cat, and leave without one, reasonably so.
Kraken has free shipping on their exhausts right now, and it looks like I could get one for ~$650 with a resonator and muffler. I still need to think through that a bit more, but likely I'll end up buying one of those soon.
First events of the season are this weekend. Knowing what I know now, I'll probably turn the boost down to 8-10 PSI and run it like that. I'm not sure if it's true, but it seems to me like increasing the boost past the point where the system is happy (IE past the point where the exhaust flows well through that 2" section) would put additional stress on the system. I'm not sure if that would be the turbo, or maybe the engine, but it seems like something would be unhappy. Correct me if I'm wrong there. Considering I only picked up an estimated ~30 HP on 6 addition PSI, I imagine turning the boost down a bit will be a very minor drop in power, and likely keep everything running happier.
My guess is a bit of everything. I had a catless 2.5" crush bent exhaust with my SR20 turbo setup years ago, and I went from 165hp to 185hp when I went to an Artech 3" mandrel setup. Zero other changes. Felt amazing, miss those days, low hanging fruit is fun.
Well, as if it was a sign from above, my exhaust kept disconnecting at the slip joint this weekend at autocross. I eventually fixed it by drilling some holes and using wire to hold the two pipes together. I'm guessing a hanger finally loosened up enough to allow the exhaust to move around because I've ran this exhaust setup since I got the car and haven't had this issue before. The wire in the photo below did not hold up, but it's what I had on hand Saturday night. Sunday at lunch I replaced it with some 100 LB stranded wire and that held up for the rest of the day.
Reminder that this was the PO's job trying to get the car to pass emissions. I know it's bad, I just haven't gotten around to replacing it until now.
The question now is whether to get the resonated or unresonated Kraken system. I don't plan on running a cat either way. I can't find any sound clips of the setup with just a muffler. The system with the muffler and resonator seems really quiet to me. I'm not trying to be a hot boy with a fart can, but I'd like to have some noise. If anyone has experience with either let me know your thoughts.
I won XB on Saturday and took second on Sunday against a couple turbo NA/NBs, some 2.5 swapped NC's and a few other cars. I had the 6th raw time on Saturday and 11th raw on Sunday. Even with the ambient temperatures in the 50's the car was still hitting 110 C coolant coming across the finish line and 50 C intake temps. The temps dropped pretty quickly once I was back in grid, but exhaust, intercooler and ducting are going to need attention ASAP.
A fellow competitor brought his NB out. This guy has an insane twin charged CRX as well that he engineering all by himself.
Turbo K, ZF5 and a Caddy diff.
Congrats on the result! That's killer you took the W against multiple similar cars in class.
Kraken catted+resonated user here. Just running the cat to keep the car from being noticeably smelly on the street. Failure to follow emissions laws in California is punishable by death.
Can confirm the exhaust is fairly quiet. It's probably just a tad louder than the stock exhaust at idle and a few notches louder at high RPM. The flipside of this is that when you open the throttle up, the loudest thing you hear is the turbo. On my car, it's probably 65% turbo noise, 35% exhaust. I personally love it, but can see the desire for more exhaust noise.
The turbo is slightly louder in real life but here's the gist of what mine sounds like. This was with the stock motor. The exhaust note is a tiny bit louder/throatier with the built motor.
Thanks for the link and the praise @Z_WAAAAAZ I was actually looking through some of your posts to find some videos since I knew you were running their system. With my current setup I mostly hear turbo as well (Cat, no res, muffler).
Further pro's of running no resonator are weight and money savings. I also figure it would be easier to add a resonator later than to remove one. I don't imagine I'll actually try removing the resonator if I get one in the first place. Decisions, decisions...
I was at home Depot today and browsed a bit trying to get a better idea of splitter/ducting materials. I found a few things that seem like they could work. No idea when that will happen, but we've got a bigger event down in Winnemucca in May and I'll need to have something figured out before then.
I have no idea if I'll end up going down this route, but another thing I've been looking at is the OEM Nissan R35 intercooler. From what I can find, it seems like this Intercooler (half of the stock R35 setup) would be about 396 cu inch, which would be a bit more than most of the intercooler kit's I've found. I believe the outlet on the left could be flipped, as the flange looks symmetric. It's a 4" thick core I believe. Maybe obvious, but this would be an over the radiator setup. If nothing else I figured I'd mention it here, as it seems like someone could make that work.
Biggest downside here is that the outlet pipes appear to have unique flanges. Being an OEM part though it seems like replacements wouldn't be too hard to find.
Also, the other side of the IC does have bolt holes to use for mounting.
Kraken 3" is ordered. I ended up going catless, resonator and muffler. It sounds like the muffler can be removed, connecting the V-bands before and after the muffler to create somewhat of a center exit setup. I might play around with that if it's way too quiet, but I doubt I'll need to.
Further updates from last weekend. The blender bottle catch can caught a lot of attention and no oil that I can see. Win win. It did melt a tiny bit where it was contacting the metal power steering reservoir, so I added a bit of heat shielding tape on the bottle. We'll see how that holds up.
I still need to figure out better routing for the coolant reroute hose. I'm hoping to get around to that within the next week, possibly addressing a few other small issues I have while the coolant is drained.
Debate is ongoing on whether I'll do an over the radiator intercooler setup, or something more traditional. I like the over the rad setup for the short runners and fewer couplers, but I'm wondering if it's worth the hassle. It seems like most people go around the rad. Not sure if there's much sense reinventing the wheel.
There are a couple of events towards the end of April/beginning of May. I want to get all of these issues addressed by the time those roll around so I can test them before heading down to Nevada for a regional event in mid-May.
I expect exhaust note videos once you get the setup installed! Good luck with the rest of the chore list as well.
Looking at the R35 and other OTR IC setups, I can’t help but feel like “tanks” on either side of the IC would impede airflow through the radiator. To what degree that would affect coolant temps in practice, though, I have no idea.
Don't worry Z, I'll make sure to get some sound clips. I meant to grab some video last weekend at autocross, but I need to figure out new camera mounting since I removed the bar I used to mount my stuff to.
Also, I grabbed some pictures of the undertray. The main issue is that it bows because it isn't wide enough. I've still got some leftover material, so I'm thinking I might try to cut the center and extend it by an inch or two.
I'm also planning to pull off the front bumper and do some more serious ducting. I've got a few strings to pull in the ECU to help with cooling (kicking fans on a bit sooner and running both fans at speed), but I'm already nervous about some of the summer events where we'll see 90 F temps or higher.
Haha, I feel that. I had the same issue with where to mount my GoPro after I removed the same bar in my car. I hear @redursidae makes a pretty mean roll bar mount
Good luck with the continued ducting project, looks like you're getting closer to a finished product with it. You given some thought to venting the hood, too, once the ducting is done? Even a couple generic vents placed in the right location will make a sizable difference in cooling. The only reason I mention this is that it's relatively low effort compared to the ducting project once that's already done.
I'm pretty sure I was searching about hood vents yesterday. It's definitely on my mind.
The more time I spend in that engine bay the more I want to rip out AC and PS as well. The AC condenser isn't helping cooling, but I'm hesitant to rip it out since the system is still working. I wasn't able to use it at idle all of last summer (ECU issue) and I was fine. Never had AC in highschool/college either. I might leave it in for the summer, see how much I'm actually using it and reevaluate.
Fixing the AC I broke in my Miata was one of the best things I've ever done to that car, even though I lived in Michigan at the time. My friend with an RSX ignored my advice and removed it, now he is regretting that as it's unenjoyable to drive in NC summers. Not having it in high school and college is one thing and I've BTDT, but once you've got a stable career it's nice to arrive to places without a swampy shirt and pants.
I don't enjoy sweaty back syndrome... AC will probably stay in until the system pops a leak or something. I doubt I'll put in the effort to fix it if it blows.
As I do more research about intercoolers and ducting, I'm wondering if some of my temperature issues are caused by the restrictive exhaust. Given the low power gains I saw when I added 6 lbs of boost, I'm thinking that the turbo is running inefficiently and causing it to generate more heat. I've found some discussion that a restrictive exhaust will lead to higher EGTs. I'm not counting on the exhaust to fix all my issues, but I'm hoping that it helps.
I have some datalogs from autocross (bluetooth logging via phone is great), and my coolant temps dropped from 111 C to 96 C in less than 2 seconds once I got off the throttle. Intake temps are pretty slow to drop (steel piping maybe retaining some heat?), but they still went from 51 C to 37 C in about 40 seconds. I'm not sure what to make of that, but it seems like my coolant system isn't super far off from working.
If anyone who's more experienced with this wants to tell me I'm on the right track with my thinking, or that I'm an idiot, feel free.
I'm interested in feedback on this as well, a 15*C drop in coolant temp in 2 seconds is kinda outlandish. Only time I've seen that is after draining and refilling coolant, when my car was passing an air bubble through the system. Were temps consistent before and after that drop?
Edited to add that this is a 80 C thermostat with the primary fan kicking on at 90 C
You can see below that the coolant temps are very spiky. Returning to ~90 C very quickly when I get off throttle. Intake temps rise steadily.
This is logging over bluetooth so I believe the data rate is a bit worse than with a cable/laptop.
Got a few things buttoned up on the car. I finally got the reroute hose trimmed and... rerouted? I like the new placement better, although it is still contacting the fan shroud and intercooler piping. Once (if) I figure out how I want to route new intercooler piping then I'll address the contact issues.
I used a couple cable clamps to secure the hose to the intake manifold. I also bent the bracket that holds the fuel lines a bit. With all of the expanding the hose does when it warms up I won't be totally surprised if this needs adjustment every once in a while. So far so good though.
While I had the cooling system drained... well mostly drained, I put some heat sleeve on the heater core hoses. I should've done this when I put them on in the first place, no idea why I didn't. I think it's probably overkill, and I've got the heat shield for the turbo already, but I figure it's not going to hurt.
I replaced the aging coolant overflow line as well, using some of the silicone hose that was previously used to cool the turbo.
I forgot to mention previously, but I had 3d printed a locking latch for one of my soft top latches. That broke last weekend, so I've ordered a couple more that should be printed sometime this week. I think this one broke when I had the top adjusted a little too tightly. I think it lasted about a year though, so hopefully the new one holds up as long or longer. In the meantime I've robbed a latch from my hardtop, which won't see much use until we road trip again.
Oh yeah, I also found some ducting material growing in the wild. Harvested it on the way home last night.
Both of these signs had been pulled out of the ground already and hadn't been touched in a week or so. I'd been seeing them when I'd go for walks and it seemed like they were destined for the landfill.
I thought I read the same post twice from you two regarding the chloroplast election signs lol.
Regarding the CLT temps, that's interesting how spiky they are. Maybe that's just a by-product of running a turbo car full bore at autoX speeds with no ducting, though. I wish I had some pertinent data to reference, but I did my undertray/mild ducting/hood vents before my car was turbo'd (stupid overkill lol), and just remember temps on track staying pretty consistent.
In for a log at your next event once the undertray is done.
There's a local church who spread a lot of "Celebrate Easter" signs throughout the area, so I'll probably snag some of those if I can.
As for the spiky coolant temps, I believe that's due to datalogging over bluetooth and having a slower data transfer rate. I usually smooth the results in MLV and I believe I have a slight filter setup in tuner studio as well.
Yesterday was largely spent on my back with a sharpie and a pair of scissors. I was going to try to improve the storage tote undertray but ended up abandoning that and going all in on the coroplast.
First thing to do was to stuff some AC weather stripping down the sides of the radiator. The stuff condenses down pretty nice, and with the help of a long screwdriver and a pick tool I was able to get it to span the whole radiator.
This stuff is cheap as well. I think the 42" strip was under $5 at home depot and was enough for the whole radiator. Crappy photo, but you get the idea.
After getting that done I started doing the typical routine. Cardboard templates, transfer to the coroplast, etc...
The metal sign stands were really useful to join the pieces together. I also used one underneath the main section to help prevent it from buckling at speed.
Still not a perfect job, but once I've done this job another 5 times I think I'll be a lot better at it /s. This setup seals to the underside of the radiator miles better than the storage tote did, partially due to my... craftsmanship.
I used sections of the sign posts to join the sections together and injected some hot glue into the chambers of the coroplast to try and seal things up a bit, while not being permanent.
I see why Emilio likes this stuff. Easy to use and seems pretty sturdy. If you don't want to scavenge for it it's still pretty cheap at home depot.
I did a test run yesterday and everything stayed together. It was super windy out, not the most pleasant with my raggedy soft top. Temps seemed to be staying right at thermostat temp (80 C) while cruising, if not a bit below. I still saw some pretty good temp increases when I got on it. I'm really wondering if that's being caused by my exhaust (or maybe a boost leak). Boost is turned down a bit for now, although I'm not seeing any concerning temps when street driving. I also got a funnel so I can make sure the radiator is good and bled.
This makes me want to do an over the radiator setup even more. Not having to route around the intercooler piping would make this job brainless. I'm hitting analysis paralysis with that job though. The only ebay intercoolers I'm finding in that style are either barely big enough (11x11x2.75" core) or massive (I think it was about double that last one). Further, I'm not sure how much modification I'd need to do to tilt the radiator back. The lines coming off the power steering reservoir are already touching the fan shroud, so some bending or relocation might be necessary. We will see. Maybe I'll just relocate this PS Res straight to the bin.
03-19-2024, 05:16 PM
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