Roman

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.

FFS my new wideband shit itself today. It lasted a month! Time to throw this shit heap innovate controller in the bin.

Oh yeah just remembered. When you put it back on, there are some valley areas that need sealant, and some that if you fill them up your motor starves of oil haha. So take VERY CAREFUL note of which areas under the big cam cap have sealant on them.

You need to take the cam gears off. So you need a large hex head of the right size which undoes the front cap, and then there's another large hex under it which takes the gears off Then there are bolts for that front cover under there, then it all comes off. Before you do anything further, put those pulleys back together ASAP or they'll explode across the room and you'll never get them back together

Not mufflers as such, but check out this vid... very interesting!

Haha, no graphs but give it time... It seems regardless of whether manifold is aftermarket or factory, the total length to the 2>1 or 4>2>1 seems to be about the same in each case. Which means the extractors finish somewhere under the passengers feet. So probably impractical to make a 4:1 thats any good. Could probably keep the existing 2>1 section and just make a different 4>2 and see how that goes. To be honest though I've got no idea how you can quantify the change in how an exhaust manifold does its thing. Would the fuel requirements change? Or is it just one of those things you cant tell without a dyno.

I've been thinking about trying to make a different exhaust manifold, basically to try and have a longer Straight section on the runners before the first bend. There's heaps of space for it. Currently 1 runner has the bend immediately after the flange and the other is maybe 100mm or more away from the flange. Also, my exhaust ports are larger than standard and I had to die grind the hell out of the manifold to be the right size. But it steps back down to smaller diameter which probably isnt great. So it would be interesting to see what happens going up a pipe size. For interests sake thought I'd draw up some bends in solidworks and see how close I could get to drawing up an equal length exhaust manifold. In my mind it's the same process that you'd do on the bench tacking things together but a lot quicker to readjust angles. Still took ages, would take a zillion times longer IRL! I thought I might end up drawing a model that needed a zillion cuts and welds and bends to work, but it looks as though with the magic of CAD I could probably bang something together from off the shelf mandrel bends, only 3-4 parts per runner to get equal length within a few mm. Based on the test model, wtih some accurate cutting and coming up with a way to index the angles between parts from the model. Only 3 parts per runner would be required: (excuse the wonky angle blue pipe, solidworks crashed before I saved it and CBF redoing it) I reckon it looks feasible enough to spend a bit more time modelling engine bay available space, exact port spacings etc and mock something up. Anyone tried making a manifold from cad drawings before? Might pull the manifold off and measure some stuff in engine bay next time there's a rainy few days.

Hah. the bread bin rules.

Has these weird lines through it... Cant see it from the inside, but it's annoying. concerned that it's delaminating or something like that? Good idea to get screen replaced, or not to worry.

What do you think will happen with larger dia pipes? I'm guessing it would lower the tuned length rpm of the manifold, all other things being equal Or is it more about just hoofing the air out a bit better.

His 4age extractors wont fit the 3SGE that he's mounting in the car now, so he's remaking them.

If you plumb it back into pre-throttle body somewhere, when it makes boost the pressure on both side is balanced so no leak. Depends on the ISCV unit I guess but not plumbing back to pipe and you'll have air blowing back out through it.