Limequat's 4.2l I6 Swap
- Thread starter limequat
- Start date
So, a new (professionally) welded aluminum oil pan is on the Supra. I welded up the up-pipe to manifold connection and put her all back together again. Been fighting laziness and a dead battery. I fired it up and it was running rough. Really lean. Trying to tune it last year with the hole in the up-pipe screwed things up. But the PCM is correcting, and it smooths out pretty nice after a couple of minutes. What the hell lets go for a drive!
The 4200 devoid of any torque management or torque converter is incredibly responsive. Add boost and it becomes tough to control ones self. So when I first eased her out onto the pavement it was less of a "easing" and more of a full throttle, fishtailing launch. And then: BANG! The power was gone. The engine got rough and didn't want to idle. I came to a light and tried to heal-toe to keep the revs up while still stopping, but it stalled. Turn the key, <click>. Damn.
A good Samaritan was kind enough to help me push it out of the road. He even offered to help diagnose the problem. When I popped the hood he couldn't get away fast enough. "Oh I used to know a little bit about the older ones." The Supra is now knocking on 30 years old. So the above picture is my wife saving my bacon.
Turns out the BANG! was top and intermediate boost pipes saying adieu. With no solid connection of intake pipes, the MAF was insistent that there was zero airflow and the PCM delivered fuel accordingly. In the end, I fudged the injector scalar just to get it started and limped back home.
Fast forward to this morning. The I/C pipes are cranked down 'bout as hard as I can manage, and there's about 30% more fuel in the tune at idle. Battery is charged. The engine rolls over twice, catches and settles into a smooth idle that only I6s can do. The PCM is hardly adjusting the mixture at all. So far so good. Up and down the driveway, no hiccups. She wants to run. We set out to the dirt roads around my house where I subject my neighbors to a series of 1st gear half throttle pulls: BrrrrrrrrrRRRRRR WHOOOOSHHH!
As I round the bend en route to my drive way, I can't take it anymore. I roll into the throttle at 3k rpm. The VVT turbo is instantly on the case. After about a second and a half -even though I haven't even hit WOT- the big GT37 is blowing 9 psi and the 275/45/17s are fighting for something to grab onto.
Oh my dear Mary mommy of Mohommad it is so... BANG! The steering goes stiff and the throttle is dead. I coast it into it's perenial parking spot and turn it off.
Until next time, Supra. You nasty tease.
The 4200 devoid of any torque management or torque converter is incredibly responsive. Add boost and it becomes tough to control ones self. So when I first eased her out onto the pavement it was less of a "easing" and more of a full throttle, fishtailing launch. And then: BANG! The power was gone. The engine got rough and didn't want to idle. I came to a light and tried to heal-toe to keep the revs up while still stopping, but it stalled. Turn the key, <click>. Damn.
A good Samaritan was kind enough to help me push it out of the road. He even offered to help diagnose the problem. When I popped the hood he couldn't get away fast enough. "Oh I used to know a little bit about the older ones." The Supra is now knocking on 30 years old. So the above picture is my wife saving my bacon.
Turns out the BANG! was top and intermediate boost pipes saying adieu. With no solid connection of intake pipes, the MAF was insistent that there was zero airflow and the PCM delivered fuel accordingly. In the end, I fudged the injector scalar just to get it started and limped back home.
Fast forward to this morning. The I/C pipes are cranked down 'bout as hard as I can manage, and there's about 30% more fuel in the tune at idle. Battery is charged. The engine rolls over twice, catches and settles into a smooth idle that only I6s can do. The PCM is hardly adjusting the mixture at all. So far so good. Up and down the driveway, no hiccups. She wants to run. We set out to the dirt roads around my house where I subject my neighbors to a series of 1st gear half throttle pulls: BrrrrrrrrrRRRRRR WHOOOOSHHH!
As I round the bend en route to my drive way, I can't take it anymore. I roll into the throttle at 3k rpm. The VVT turbo is instantly on the case. After about a second and a half -even though I haven't even hit WOT- the big GT37 is blowing 9 psi and the 275/45/17s are fighting for something to grab onto.
Oh my dear Mary mommy of Mohommad it is so... BANG! The steering goes stiff and the throttle is dead. I coast it into it's perenial parking spot and turn it off.
Until next time, Supra. You nasty tease.
I'm with T3rril79 man, you spin quite the tale...
That "BANG" sounded pretty familiar to me. Hence why we'll be either v-banding the pipes together, or more likely just a weld-on bung and bracket setup like the old Group A cars used.
Anyway, good to hear she's such a beast. No surprise really, with an I6 of that size, and I'm assuming you kept the stock relatively high compression pistons... Would love a ride if you're ever in the same area as me.
That "BANG" sounded pretty familiar to me. Hence why we'll be either v-banding the pipes together, or more likely just a weld-on bung and bracket setup like the old Group A cars used.
Anyway, good to hear she's such a beast. No surprise really, with an I6 of that size, and I'm assuming you kept the stock relatively high compression pistons... Would love a ride if you're ever in the same area as me.
OOOOOHHHHH....
Aluminum v-bands with an o-ring seal. Good to 75 psi. Yes, this is what I need.
http://www.amazon.com/3-5-Aluminum-V-Band-Clamp-Rings/dp/B004FHU5ZO
Aluminum v-bands with an o-ring seal. Good to 75 psi. Yes, this is what I need.
http://www.amazon.com/3-5-Aluminum-V-Band-Clamp-Rings/dp/B004FHU5ZO
limequat;2011890 said:
10.3, not bad at all. Gives me hope for both my Supra build, as well as the Miata if/when I turbo that one...
As for v-band connectors holding under boost, I don't see why they wouldn't. I've never measured the psi of exhaust gasses, but considering it's flowing through a 3+ inch pipe, there is still a LOT of air flowing through it, and your exhaust never blows off like intercooler pipes? Like I said though, I've never measured the exhaust pressures. Looks like you found something that should work though.
As for the bung and bracket setups I've seen, all it is is a threaded bung (think like how your wideband o2 sensor threads into your exhaust) welded onto the intercooler pipe, and one on the throttle body, turbo outlet, and intercooler inlet/outlet. The bracket is usually just a flat piece of metal with a hole drilled in where the bung will sit underneath. Put a bolt through the bracket holes into the bungs on either side of the piping connection, and you have a fail proof mechanical connection for your boost charge pipes.
Edit for clarification: This is a supplement to using traditional couplers and hose clamps, not a full replacement.Sorry, I don't think I have any pictures, can't seem to find any unfortunately. You're a smart guy though, should be able to figure it out. A good alternative if the v-band thing isn't your cup of tea.
You might also look into constant torque clamps, they seem to hold up really well on the Caterpillar applications.
I hung a bracket down from the block that retains the boost tube. It's a single mount point on each end, so there's plenty of play, but not in the direction that would allow the tubes to separate like they were before.
Here's the attachment on the boost tube, which I now realize looks a lot like a robot nipple.
Here's the attachment on the boost tube, which I now realize looks a lot like a robot nipple.
Ok, so we already know that limequat's welds look like shit. The question is, does it hold boost now.
Well...
Here's a HPTuners histogram that shows peak manifold pressure in KPA for each point of the spark map (RPM vs Load):
So...the numbers are a bit small, but -yeah- at least one of the squares starts with a '2'. As in 15 psi. Oops! Sorry, Supra!
So, yes, the tube mod holds boost. No, the boost controller is not quite dialed in, lol!
Other factoids: positive pressure by 2300 RPM. What should be max boost by 3000 RPM. Pulls HARD. Like scary hard.
Well...
Here's a HPTuners histogram that shows peak manifold pressure in KPA for each point of the spark map (RPM vs Load):
So...the numbers are a bit small, but -yeah- at least one of the squares starts with a '2'. As in 15 psi. Oops! Sorry, Supra!
So, yes, the tube mod holds boost. No, the boost controller is not quite dialed in, lol!
Other factoids: positive pressure by 2300 RPM. What should be max boost by 3000 RPM. Pulls HARD. Like scary hard.
I can't find better pics of it yet, but something like the bracket that's holding the pipes together. They're used in conjunction with the Tbolts.
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How's the HP Tuners? It works with the factory AFM & ECU right? Do you have to do much tuning for idle & closed loop operation.
Not really, pretty easy if you have a Wideband on it, I have HPT and EFI-Live but much prefer EFI.limequat;2013640 said: