Roman

Three things relevant-ish to this thread but off topic to what's currently being discussed: 1. I went to a Taupo trackday, went out for first stint and then came back in and checked the logs. AFRs were good, everything running well.. Although, why is my intake only getting to 96kpa at WOT? Has the bellmouth inside my airbox fallen off? Oh wait... Checks the Barometer and that's at 96kpa because the track is ~400m above sea level Everything working as intended. 2. I've been running a Tomei copy adjustable FPR to get a higher fuel pressure, currently running ~70psi at WOT and have vaccum connected to reduce pressure when at low load... But my fuel pump sounds like it struggles a bit. I think I'll switch back to the factory FPR to simplify my fuel system and give my fuel pump a bit of a break. I've already had a fuel pump fail when I've been quite far from home, not keen on round 2! Maybe I should put the car on the dyno first though and see if there's any benefit to the higher pressure. I think the way to go here is come up with a number first, then stick to that. "If it makes less than xyz HP difference, I'll get rid of it" 3. Something interesting regarding IAT, previously I've always had my IAT mounted somewhere ahead of the throttle body. When I had it mounted in a 3" pipe, as soon as you mash the throttle the IAT would change really quickly. Then when I built my new airbox which has much lower airspeed due to big volume, the IAT responds really slowly. Since then, I've mounted it inside the plenum behind the throttle body, and have found that the IAT responds very slowly annnnddddd it consistently stays ~10-15deg hotter than before. I'm not convinced as to whether this is the plenum heat soaking the sensor and giving a falsely higher temperature, or whether this is actually more indicative of the actual air temperature after it's spent time in the plenum heating up on the way in. Since my air intake currently takes air from the engine bay rather than an external source, it may just be that the average engine bay temp rises over time and this is what the sensor shows. It would be interesting to setup a compensation table relating to a surface mounted thermistor on the plenum, you could either prove that it's the difference or rule it out. And maybe a 2nd temp sensor just in engine bay to compare to haha.

Hi there, Just using the functionality built into Solidworks. It's very cool, you should definitely have a play around. Feel free to flick me a PM if you want some more info on how to set it up etc.

They were cheap and plentiful, but then everyone blew them up because they were cheap and plentiful. So now they arent haha.

Sheesh I bet that thing's a bit of a laugh! That's a lot of power for a light car. Looks awesome man.

Yeah now that I've got a pair (even though they're fairly nuked) it seems a bit more affordable to get just another pair. Not sure what other options there are though, Achilles 123 are cheap but people say they overheat easily, which is exactly what I want to avoid.

Heh thanks... That's what so great about Oldschool, the variety. Boxy 80s cars arent for everyone, it's bloody good fun to drive though! And not too much of a chore to work on when things go wrong

Probably a little (a lot) outside of my budget though! R888s are something like $1600 a set these days.... yikes.

Looks like quite large diameter pipes? Making new extractors has fallen to the CBF pile haha. a full set of semislicks is biggest thing on the agenda! also these dreadful tires I've got on the front, are actually really great at soaking up bumps. The car's a lot nicer on the street compared to T1Rs. Might buy shitty tires with soft sidewalls for the rear too, for weekend driving etc.

Hi people, I would like to title this post: The success of rubber and the failure of man. Last trackday at Taupo - I only got a handful of laps and managed a 1:56 which is a new personal best! So I knew the car had some more time in it with a bit more practice. This thursday just gone, I gave it another attempt. With some better lines, I managed to scrub a whole extra second off my time, I was super chuffed with that! One of the differences to last time though, is more negative camber in the front (going from 0, to -2 degrees) So the car was feeling great, the initial turn in was superb. I was feeling suuper confident, doing some kamakaze runs into the sweeper which I overcooked a few times trying to brake too late... And then for the first time at a trackday this happened... Woops! I had a huge lockup, and flat spotted my front left tire down past the tread level. It felt like I was driving on a cube, not ideal. So off I go to the local tire shop. "Hi, do you have any 205/50/15?" "Sorry dont stock these" "wtf? Shit." "Try the place around the corner" Off to the second place, same answer... nothing in stock.... shit shit shit. until... "Oh, I've got some second hand semi slicks though" "Go on" "Two R888s for $60 fitted" "Done deal!!" Frigging amazing! So I get them fitted on the front wheels, then smug face back to the track. After running out of people to smugface to while telling my story, head back out... Very mindful that I'd have a lot more grip up front but still the same out back... So I wound out a bunch of the rear bias. Out on track... Holy shit! Sector times keep tumbling and tumbling, GPS is showing going faster and faster through sectors. Life is good I had a few... err.... incidents while getting used to the different grip level Getting more confident on the brakes... Sector times dropping like crazy... And theeeennnn.... Smoke coming from the front left, brake fluid smell and a knocking noise... shit I hope this isnt the wheel hitting the caliper or something. Back to the pits... I take the wheel off, and all is well. What made that noise and smoke then? Oh... Oh fffs. GNNARRRRR! My first experience with semis, over in about an hour because I noobed the braking again. All smugness instantly erased from my face haha. My fastest lap was only 0.2 seconds quicker than road tires, because it was hard to string a whole lap together without having the rear of the car come loose with the grip imbalance. Regardless, I was absolutely fizzing about how well the car ran. The 8000+ rpm rev limit now has just brought the car alive. I called it a day, and headed back down to the tire shop with my tail between my legs. Feeling like an absolute noob for wrecking the tires they fitted about an hour ago. "So, ahhh... I wrecked one of the tires, my bad. Do you have anything like a 195 or 185 that I could get home on? Just a normal road tire" "Yeah I think we've got some 185s here, same deal as before... $60 fitted" "done deal!" While he was taking the semis off, he said "Oh yep, this one is flat spotted pretty bad! Leave this one with me, and take one of these others so you've still got a good pair" Holy crap, could an experience with a tire shop possibly get any better? So with my car amazingly intact, and a decent pair of second hand R888s in the boot. I head off for another 2 days of tootling around the central North Island, as pictured below. Smashed through a few tanks of gas, with the engine running like an absolute dream. Ran 90% of the time with cruise control on, and enjoyed the scenery. I made it back to Auckland in one peice with no major issues. Best trackday experience ever! Big thanks to Tom / Testament for helping me out over the weekend.

Haha awesome

I've found the schematics for the fuel delivery logic in an MEU ECU:

Roof racks are cheating! The fun of an MR2 is coming up with ways to work around the lack of space. With my SW20 I used to jam the nose of a surfboard under the spoiler, and then tie the rear of the board around the roof. (in a board bag of course) Have also transported 5 extra wheels and tires. One behind each seat, two on the passenger seat, and one in the frunk. I can appreciate the gimmick factor of the racks but in my opinion it kills the sleek sort of look of the car. Practicality be damned!

E85 is too much of a pain in my opinion. Not much gain on NA but using a shitload more fuel. Yeah max revs is the way to go!!

I'd say it's not really practical due to lack of inputs and outputs on an Atom. As although you can wire in the flex fuel sensor itself, you need to run modelled fuel calculation which really needs fuel pressure and fuel temp inputs to be accurate. As well as very accurate deadtimes etc for the injectors. What sort of motor, out of interest?

Anyone know who brought the red carina along? I saw it on TM about a week ago in Wellington(?) so wasnt expecting to see it here

The bend on each one doing a 90 deg turn to lay throttles down flat right? For sake of non shitty flow I'd be inclined to look at having the bend made from the 45 ID pipe. Then use something thick walled welded to the flange that you can die grind a transition into the 38mm oval or whatever. Time consuming doing 12x, but maybe the cheapest option that isnt going to have crappy flow into the head. Or otherwise if you dont have the height for that. maybe get a 45mm ID 90 deg bend, and then split it down the middle with a bandsaw. Then squash the ends down to 38mm and cut a taper so it transitions nicely. You'd also get a good transition in cross sectional area across the whole length of the piece. Which again, is time consuming but that's V12 life! Unless you think it looks ugly I wouldnt be shy about spacing the throttles further away from the head than what you're currently planning. As it might make things easier and your total runner length will want to be reasonably long anyway. If you can show us some photos or sketches of what you're wanting (it's a 90 deg bend right?) then I can try sketch up a few options in cad that might work well and be easy to fabricate.

A 1% or 2% difference in pressure in exhaust likely doesnt directly equate to 1% or 2% more power though, especially when the pressure differential is likely a lot higher at the time of exhaust gas being pushed out of the port. And as you say if your exhaust port is a bottleneck then extractors onwards might not be the point of restriction anyway. I do understand what you're saying though, when you're scratching for any little benefit. This would seem to indicate that a bigger pipe for my car would have been better, but when I went to the shop the size of mandrel bends in 3" meant it would have been a mission to get around my diff. I wonder how much pressure drop you'd see from a perfectly timed pulse from a tuned length extractor pipe. It's enough to make a 2 stroke motor work so I'm guessing it's reasonable. Will be interesting to see how this compares to a real exhaust though, as always results need to be considered in context (in this case an overly simplistic look at a perfectly straight pipe with no pressure pulses) I'll buy some long hose and plug my other map sensor back in tonight and get some readings though, will be interesting. I wonder how much resolution you can get from a map sensor if you looked at it with an oscilliscope or similar, wonder if it could detect individual peaks and troughs.

Yeah definitely not Toyota, sometimes people fit Sigma lower control arms to give more camber in Toyotas, so its possible someone went that whole bit further and chucked the whole lot in there haha.

Or a gen 3+

If you've got say 250+hp then sure but no point putting a 3" pipe on a Honda City or whatever. I'm gonna run my 2nd map sensor into the exhaust somehow without melting all of the things and see if it comes close to matching the sim. But pipe length itself seems to contribute bugger all to pressure increase. Might chuck some bends in it and see what happens

Been playing around in CAD again Okay so it seems big pipe is best but where does it start to be diminishing gains for a real life HP amount. Some TL;DR stuff in the spoiler below but it looks as though this would be a reasonable guide for exhaust size vs power output (green is good red is bad) The actual pressure gain, given some real life pipe sizes and real life flow rates seems very low (the green areas are below 1psi pressure gain across 5m pipe) If you found where the low pressure zones at the back of your car is, and had the pipe exit there. When you're going at speed this could end up making more difference than going up a pipe size or two, depending on power level. If we consider that a 3" pipe flows at 100% (as it's the biggest sized pipe tested) and look at the % effectiveness of smaller pipes, it becomes clear that you take a big hit going to smaller pipes with big HP numbers but if you've got ~150hp or whatever then it makes bugger all difference what size you use. There's less than 2% loss going to 2.25" but you save a bit of weight and have more clearance etc. Some gibberish and graphs below

It's mounted quite far down, somewhere below passenger seat rails so plenty of distance. Angled upwards at say 10 o clock. I think I'll need to tone down my idle strategy and try keep the revs down to help with the thermal shock thing. I've never driven it while its been powered off. However it currently turns on the unit with ECU power on, some people have suggested having it turn on with fuel pump so it doesnt pre-heat if you're sitting there with motor off. I hadnt driven my car for maybe a week, then when starting it today the sensor went pooz. So maybe it was condensation or something + thermal shock of starting or whatever. Might try the 14point7 unit but seems odd that you cant free air calibrate it. although its a pain it seems like a good idea.

Heh nice! Yeah I emailed the the guy, I'll see what he says. Not holding my breath though. I guess it's just mostly disspointing because everyone says the new sensor type lasts for ages but it didnt.

It's possible to put them back together, its just 100000000000x easier to not have to hahaha. You'll need to make a jig that keeps everything aligned on those outer bolt holes while being able to push the spring back in.