Aus NA6 -a Churbo lesson
#1
Aus NA6 -a Churbo lesson
Hi all,
I've been trawling the MT forum for the last few months and asked a few questions here and there, hopefully none too stupid.
My build is up to a stage where I I've finally got something to share. It's nowhere near to a point that I'd consider finished but we're on the way.
This is my first project like this and am having a great time learning a bunch.
There's a cringe worthy 'before' pic in my meet and greet thread and now here's the current state of the car:
Mechanically, I've tried to stay with what has been proven to work with other's cars on MT. With a goal of a ~200HP reliable fun street car.
So far I'm working with, roughly in the order of what was done (I'll add links where I can for any other Aussie's reading this):
-'89 1.6L with ~260,000km
-Kit Megasquirt MS2 with a $7 bluetooth adapter mod
-AEM wideband
-second hand BMW TPS from Gumtree
-Flowforce 640cc injectors from Beavis Motorsport (after buying knock off eBay RX8 injectors and sending them back....)
-Xtreme HD clutch (also replaced rear main seal and had a leaking rear gearbox seal to sort out as well)
-eBay China turbo .42AR compressor, .48AR exhaust (was about $300 dollerydoos landed at the time, specs matching what I found recommended on MT).
-ebay intercooler and piping
-Turbosmart plumb back BOV and manual boost controller
-Oil lines and later the 3" turbo back stainless exhaust made up by a local parts place Golebys parts (Great bunch of guys with a lot of pride in their work)
As part of the Megasquirt install I used a BMW TPS and made a really simple bracket with a strip of Aluminium. I had to cut a little off the throttle body shaft but the original TPS would still work if I had to refit it for whatever reason:
And the engine bay at the moment:
My next job is to plumb back the BOV, fit some proper 5mm vacuum line to the boost controller and make an air box for the intake. Then probably a coolant reroute of some sort.
I'm still at the very early stages of tuning, mainly battling with getting my head around acceleration enrichment and trying to smooth out spikes in AFRs. It's good fun to play with
I've been trawling the MT forum for the last few months and asked a few questions here and there, hopefully none too stupid.
My build is up to a stage where I I've finally got something to share. It's nowhere near to a point that I'd consider finished but we're on the way.
This is my first project like this and am having a great time learning a bunch.
There's a cringe worthy 'before' pic in my meet and greet thread and now here's the current state of the car:
Mechanically, I've tried to stay with what has been proven to work with other's cars on MT. With a goal of a ~200HP reliable fun street car.
So far I'm working with, roughly in the order of what was done (I'll add links where I can for any other Aussie's reading this):
-'89 1.6L with ~260,000km
-Kit Megasquirt MS2 with a $7 bluetooth adapter mod
-AEM wideband
-second hand BMW TPS from Gumtree
-Flowforce 640cc injectors from Beavis Motorsport (after buying knock off eBay RX8 injectors and sending them back....)
-Xtreme HD clutch (also replaced rear main seal and had a leaking rear gearbox seal to sort out as well)
-eBay China turbo .42AR compressor, .48AR exhaust (was about $300 dollerydoos landed at the time, specs matching what I found recommended on MT).
-ebay intercooler and piping
-Turbosmart plumb back BOV and manual boost controller
-Oil lines and later the 3" turbo back stainless exhaust made up by a local parts place Golebys parts (Great bunch of guys with a lot of pride in their work)
As part of the Megasquirt install I used a BMW TPS and made a really simple bracket with a strip of Aluminium. I had to cut a little off the throttle body shaft but the original TPS would still work if I had to refit it for whatever reason:
And the engine bay at the moment:
My next job is to plumb back the BOV, fit some proper 5mm vacuum line to the boost controller and make an air box for the intake. Then probably a coolant reroute of some sort.
I'm still at the very early stages of tuning, mainly battling with getting my head around acceleration enrichment and trying to smooth out spikes in AFRs. It's good fun to play with
#2
With the china charger, I also did the supporting mods of porting the exhaust port of the wastegate and grinding a bit away to allow the flapper to open further after the first time I gave it some beans the boost crept up to 14PSI! Also upon removing the housing I noticed the flapper wasn't even covering the opening:
Thankfully that was sorted by the exhaust shop (at no charge too, woot!) by adding a collar and tack welding it to stop the shaft sliding in again.
The port itself i ground out from about 17mm in diameter to roughly 22mm and also ground and smoothed out a channel to help flow.
She holds a nice steady 8PSI now. I plan to turn it up to 10-12PSI eventually.
Thankfully that was sorted by the exhaust shop (at no charge too, woot!) by adding a collar and tack welding it to stop the shaft sliding in again.
The port itself i ground out from about 17mm in diameter to roughly 22mm and also ground and smoothed out a channel to help flow.
She holds a nice steady 8PSI now. I plan to turn it up to 10-12PSI eventually.
#4
Got around to quickly making up a cold air box this evening:
It's a small SAAS pod filter and just a sheet of 0.5mm aluminium with split silicone vacuum hose around the edges.
Just waiting on some 25mm silicone hose to show up for the plumb back BOV now and that will hopefully be it under the bonnet for a little while.
It's a small SAAS pod filter and just a sheet of 0.5mm aluminium with split silicone vacuum hose around the edges.
Just waiting on some 25mm silicone hose to show up for the plumb back BOV now and that will hopefully be it under the bonnet for a little while.
#6
A bit more to add to the log:
I started getting missing under load, so thought it was either plug leads or the stock coils giving up. Took that as a perfect chance to track down a set of Corolla coils and go COPs. $60 total for coils from a wreck and sundry parts and I have this now:
I baulked at chopping my stock igniter up, so grabbed a box of male spade crimps and then taped the connector up and tucked it away safely:
It feels so smooth now, especially made a difference at idle.
Also had an hour to do a bit of tuning on a quiet road, slowly increasing the boost as I get more confident the engine isn't going to blow itself to bits. Here's a VD of one of the last 4th gear pulls @10-11PSI:
A question for anyone reading, should I be chasing a flatter AFR at WOT still or is a bit richer at the upper end just a bit safer?
The next job will be beefing up the cooling before Summer hits, we had our first 30+ C day and within a couple minutes of hard driving the temp gauge was up to 2/3 (usually sits a whisker under 1/2)
I started getting missing under load, so thought it was either plug leads or the stock coils giving up. Took that as a perfect chance to track down a set of Corolla coils and go COPs. $60 total for coils from a wreck and sundry parts and I have this now:
I baulked at chopping my stock igniter up, so grabbed a box of male spade crimps and then taped the connector up and tucked it away safely:
It feels so smooth now, especially made a difference at idle.
Also had an hour to do a bit of tuning on a quiet road, slowly increasing the boost as I get more confident the engine isn't going to blow itself to bits. Here's a VD of one of the last 4th gear pulls @10-11PSI:
A question for anyone reading, should I be chasing a flatter AFR at WOT still or is a bit richer at the upper end just a bit safer?
The next job will be beefing up the cooling before Summer hits, we had our first 30+ C day and within a couple minutes of hard driving the temp gauge was up to 2/3 (usually sits a whisker under 1/2)
Last edited by Okisub; 09-15-2017 at 12:26 AM.
#7
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I think 11.5 -11.8 is good for boost. If anything you need to richen up the bit hitting 12 in the midrange.
Also, are you referencing to the stock temp gauge? That's a bit of an idiot gauge. If it's moving up past its normal position at all, there's danger of overheating.
Also, are you referencing to the stock temp gauge? That's a bit of an idiot gauge. If it's moving up past its normal position at all, there's danger of overheating.
#8
I think 11.5 -11.8 is good for boost. If anything you need to richen up the bit hitting 12 in the midrange.
Also, are you referencing to the stock temp gauge? That's a bit of an idiot gauge. If it's moving up past its normal position at all, there's danger of overheating.
Also, are you referencing to the stock temp gauge? That's a bit of an idiot gauge. If it's moving up past its normal position at all, there's danger of overheating.
#10
Quick update:
My overheating issue was quickly sorted with a thicker eBay radiator. Seems nice and solid for such a cheap unit:
I also knocked up a heat shield to cover the turbo as rain was fizzling on the bonnet when driving around in the wet. That couldn't have been good for the paint:
Should do the job.
Very happy with how the car is running now when it's warmed up a now. The car will only start on the second attempt when the engine is cold but I'm fiddling with it over time.
My overheating issue was quickly sorted with a thicker eBay radiator. Seems nice and solid for such a cheap unit:
I also knocked up a heat shield to cover the turbo as rain was fizzling on the bonnet when driving around in the wet. That couldn't have been good for the paint:
Should do the job.
Very happy with how the car is running now when it's warmed up a now. The car will only start on the second attempt when the engine is cold but I'm fiddling with it over time.