patra_is_here Posted February 14, 2013 Report Share Posted February 14, 2013 a leaky valve is a leaky valve. you only have 4 cylinders, if one of them isn't getting full combustion, then you're going to be down on power a lot,. hell, you could be down on power up to 25% across the entire power band. if port matching is your only mod, then go get it dynoed and compare it with stock numbers. that'll let you know what the gains are (+- the standard error of whatever dyno you're using) Quote Link to comment
Uber Deaf One Posted February 16, 2013 Author Report Share Posted February 16, 2013 I had to think about this for a while... I confused myself the other day. The one valve may not have been opening 100%, but it wasn't actually leaking. The valve seat fell out a bit, got crooked and got stuck. It lost all compression in that cylinder. Up until that point, the engine ran super smooth and it was quiet. There were no marks on the piston and the valve was still straight... there's no way it could have been falling out and tapped back in by the piston like I originally was thinking lol. Intake/header/exhaust and port matching are the only mods done to this KA. Stock internals, stock cams. It has custom drilled cam gears to advance both cams 4 degrees to compensate for the head and block resurfacing. Right now, obviously I'm just going by how the engine felt before and after. There's a lot more power up top now, like it was restricted before. There was no reason to rev it past 5500... power just fell off a cliff. Now it pulls hard to 6k and power slowly drops off past that. The intake manifold and ports on the head are pretty small stock... we took off quite a bit of material just to match the gaskets. We still need to dial in the cam gears, and gasket match the throttle body. And I think the injectors are close to being maxed out...Running against my dad's Mazdaspeed 3... before the port matching that thing would dust the 510 once we hit 4th gear, now it doesn't catch up until the 510 is well into 5th gear way past the 1/4 mile mark... and even when it catches up it struggles to actually get past the 510. I just don't see anything else we did causing that much of a difference in power. Anyone who has driven a Speed 3 knows once you get those into high gear they are quick as hell. Mazda designed them in a wind tunnel! lol Dyno is the plan. When? I don't know. A 75 shot of nitrous would be awesome... Quote Link to comment
831Sunny Posted February 16, 2013 Report Share Posted February 16, 2013 Go Turbo or No GO! :rofl: you got a sweet deal on the 4 door. and put alot progess into it.. its one bitch'n car imo.. when are you going to paint it! Quote Link to comment
Uber Deaf One Posted February 16, 2013 Author Report Share Posted February 16, 2013 A cheap T25 running 10psi and a custom side mount intercooler would be awesome. The only real expensive part is Nistune, and that's not really in the budget right now. Someday though, for sure... for now I just want to get the n/a KA dialed in and get the suspension dialed in on a track. Can't do much with the pos tires that are mounted right now. :P I have a long list of things that need to be done... paint is pretty high up on that list. It's starting to warm up finally, but still too cold at night... paint soon though. :) Quote Link to comment
patra_is_here Posted February 17, 2013 Report Share Posted February 17, 2013 ohhh well if you've got the head and block decked that's going to up your compression ratio, AND you're running cam timing changes, which is probably why you are seeing power shifted to the top end. those two mods are definitely worth mentioning haha thanks for clearing up the info about the valve too. it's all making sense now Quote Link to comment
Uber Deaf One Posted February 17, 2013 Author Report Share Posted February 17, 2013 We had the block resurfaced, but I'm not sure if the head that's on there now has ever been resurfaced. The previous head was definitely resurfaced. Probably not enough to seriously mess with the CR but I'm sure it's a little bit higher than stock right now. We drilled the cam gears a while ago when we rebuilt the bottom end, and they haven't been messed with since then. The cam timing is still off a bit I'm sure of it... eventually when I have a free weekend we're going to spend some time getting that dialed in. Quote Link to comment
Uber Deaf One Posted March 18, 2013 Author Report Share Posted March 18, 2013 First Autocross event of 2013. The suspension is finally close to being dialed in, not much else I can do until I get new tires... these 10 year old Sumitomos need to go. :rofl: These are different runs, by the way. The incar vid is my fastest run. Quote Link to comment
JAKE719 Posted March 19, 2013 Report Share Posted March 19, 2013 This thing is sweet man, LOVE the 4dr! Good work! -Jake Quote Link to comment
Uber Deaf One Posted March 22, 2013 Author Report Share Posted March 22, 2013 The 510 made 162whp/166wtq on a dyno today. Not bad for a stock KA24DE with bolt on parts. ~40hp increase over stock. Stock tune, stock cams. CCAT portwork. Quote Link to comment
510T Posted March 22, 2013 Report Share Posted March 22, 2013 Sounds great, and I love the mini fireball at :49 sec :thumbup: Quote Link to comment
Uber Deaf One Posted April 15, 2013 Author Report Share Posted April 15, 2013 This project is finally nearing completion.... Plastidip experiment... now my Panasports look like Rotas. doh! Good thing I have Panasport centercaps.... :D Just wanted to say thanks for all of the comments and advice. I may not respond to everyone but we see every post as motivation. Much appreciated! 2 Quote Link to comment
q-tip Posted April 15, 2013 Report Share Posted April 15, 2013 Been lurking this thread for a while, really similar to my build. Project is lookin good man!!! Quote Link to comment
Uber Deaf One Posted April 23, 2013 Author Report Share Posted April 23, 2013 It's finally all one color! I've been busy lately, no time to upload all the pics yet... I'll try to get more pics in this thread later tonight. Until then, here's a teaser :p Quote Link to comment
q-tip Posted April 23, 2013 Report Share Posted April 23, 2013 Lookin good man!! Quote Link to comment
Dirttrack510 Posted April 23, 2013 Report Share Posted April 23, 2013 Mmmmmmm... Tasty :) Looks great man. Moar pics pleaaaaase ;) Quote Link to comment
toonarmy Posted April 23, 2013 Report Share Posted April 23, 2013 Was one of my favorites dimes even before the paint- car and wheels look great! Quote Link to comment
Uber Deaf One Posted June 13, 2013 Author Report Share Posted June 13, 2013 Oops, I thought I posted more pics of the paintjob... guess not. :( Sorry! My buddy just picked up a white 240z, will get some pics of the two cars together sometime this summer. I'm not done with school til the end of June. :( Quote Link to comment
Uber Deaf One Posted June 13, 2013 Author Report Share Posted June 13, 2013 I finally got this thing out on a track :D I ran with NCRC Racing at Thunderhill. There's just one thing I need to get done before I track it again... Rear disc brakes. 280ZX front brakes with Carbotech XP8 track pads don't work too well with stock rear drums that I forgot to adjust the day before. I have Maxima calipers in the garage, I just need brackets, flexible brake lines and pads. Still, even without brake ducts, the front brakes never overheated despite doing pretty much all of the work. If anything, they had more grip at the end of the sessions. Might have something to do with the fact that 280ZX's are much heavier than this. After my last session, the front wheels were so hot the Plastidip was actually bubbling... Other than that, the car took the 110 degree weather like a champ! Not to mention I drove the car to the track and back home, 3 hours one way. The grip these Dunlop DZ101s (400 treadwear rating) had really surprised me and the car was pretty balanced. Little bit of understeer at the limits but a little less rear toe-in will fix that. I definitely could have driven the car harder but it's still my daily driver and this was my first track day. Last thing I wanted to do was spin or go off track. Here's the video of my final session. Little bit of a pucker moment at 7:00... Some pics... http://gotbluemilk.com/web130607/1/index.html http://gotbluemilk.com/web130607/61/index.html 3 Quote Link to comment
mcmlxxxv Posted June 13, 2013 Report Share Posted June 13, 2013 nice driving ! I envy you to have such a track you can go to :thumbup: Quote Link to comment
q-tip Posted June 13, 2013 Report Share Posted June 13, 2013 She's lookin and drivin good man!! Quote Link to comment
Son_of_a_Datsun_Guy Posted June 13, 2013 Report Share Posted June 13, 2013 nice driving ! I envy you to have such a track you can go to :thumbup: Laguna Secca's even closer to us in the Bay... talk about a cool track. Totally cool watching you eat up Miatas left and right, and the BRZ/FRS.... and the S2000. Quote Link to comment
Uber Deaf One Posted June 13, 2013 Author Report Share Posted June 13, 2013 Laguna Secca's even closer to us in the Bay... talk about a cool track. Totally cool watching you eat up Miatas left and right, and the BRZ/FRS.... and the S2000. I'm doing Laguna with NCRC this year... November 3rd ;) 1 Quote Link to comment
mcmlxxxv Posted June 13, 2013 Report Share Posted June 13, 2013 woah that is really cool ! I need to go there once in my life :p we have only one racetrack that is nice in Quebec ... and I need to drive 380km to go there :( ...It's worth it tho.. Quote Link to comment
Uber Deaf One Posted June 13, 2013 Author Report Share Posted June 13, 2013 woah that is really cool ! I need to go the one in my life :P we have only one racetrack that is nice in Quebec ... and I need to drive 380km to go there :( ...It's worth it tho.. Totally worth it ;) Quote Link to comment
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