While I'm waiting on head flow results for the next engine, (yes, I'm still waiting because the queue is huge!), I decided to do some ground work on the blue turbo K11 since it's a working vehicle and an ideal guinea pig to test out new stuff on.
Even though we made some fairly decent numbers on our last trip to the dyno, it took more boost than I'd have liked to make the power we were making. Head work and cams aside, the intercooler on the car is a bit on the small side, so I decided to look into a suitable upgrade.
The intercooler that was on the car was a 620x200x40 core 'tube and fin' unit, with pretty appalling fin density. It also had fairly small inlet/outlet at just over 41mm ID = #FAIL
After a lot of measuring and scouring of Google, I decided to go with a 550x230x65 core 'bar and plate' intercooler, which is the biggest unit that will realistically fit within the front end. Not only does this offer significantly better fin density but also provides a healthy increase in flow area as well as some additional thermal mass. Inlet/outlet sizes are also much better at just over 2" which removes any possibility of flow restriction at the power levels we have in mind.
So, it's brackets, test fitting and then time for some cardboard ducting mockups to optimise airflow through the core. Not much point in upgrading if you're not going to pull out all the stops
Mock brackets installed to assess position and potential piping runs. NSF needs a 90deg elbow welding on, as it's too tight for a silicone bend and hose clamp. That actually works better with the current hot side piping anyway and just leaves potentially a 15deg joiner on the OSF.
Well, while I'm waiting for some extruded aluminium angle to arrive to make a nice intercooler mount from, I decided to remove the turbo and manifold to check port matching. Last time I had the manifold off I noticed the ports appeared a little on the small side but only after I'd had it finish milled. I also didn't have the tools to do any porting at the time, so it went back on as it was.
Now it's been on the car a while there was enough time for carbon to build up and show any mismatching. After removal the ports on the manifold, (which were copied from an HKS manifold), were shown to definitely be too small. In fact, they were all smaller than the gasket, which is a perfect match to the cylinder head on CG engines. In particular cylinders 1 and 4 were obscured by quite a bit due to some misalignment of the flange.
So, I paid a visit to SirChris' workshop for a spot of die grinding
This is how the manifold started out, bit of an old photo this but it serves to show how things were.
After a short while with a nice sharp burr.
Not finished yet. This is just a rough grind to allow me to offer it up to a spare head I have with an old pair of gaskets, dob or 2 of silicone to make them stick and check to see how the alignment is now. I'll then see how much finishing is required and where and do some final minor grinding ops plus some finishing with some flap wheels where it's needed and to even out the port shapes. It's always good to check along the way when you're removing metal, especially when it comes to No.2 cylinder, which doesn't have a great deal of gasket area
Thanks to an empty Cheerios box, I was able to make up a template for the cylinder head to check the newly ported manifold for alignment.
Ports line up a treat with no obstructions and, if anything, there's a slight lip now which was the aim to help promote anti-reversion. So once the flap wheels arrive next week, I can smooth out the surfaces and this is good to re-install
Extruded aluminium angle arrived yesterday. So that was cut to length and drilled for intercooler placement and bolted to the front cross member.
Dropped the intercooler off to my local welder to have the cast elbow welded up. It's now sat in the car to assess final placement for hose clearances. A smidge will get trimmed from the chassis to allow adequate hose clearance on the NSF for sure.
Once it's in it's final place, I can get to working on the bumper and start with the cardboard mockups for some ducting
In the meantime the turbo has made it's way indoors and has been split so I can send the turbine housing to Zircotec to be coated. The turbo jacket was only a temporary measure and I'll be glad to see the back of it.
If that wasn't enough, I decided I should invest in some tools. Good old eBay bought a decent degree wheel. Magnetic stand, digital dial gauge and TDC tool are en-route, so I can check the cams that are currently in the car. This will allow me to determine what we do next cam wise to help squeeze a bit more out of the engine
A decent set of measuring tools are something I've been looking to invest in for a while. Especially those that allow me to time up an engine. Very useful, especially for what I'm aiming at.
I have the specs of the cams that are in the engine and they're pretty docile to be honest. On paper they sound radical but when you look at the actual data, it's a different story. These were budget cams, so were re-grinds of a standard cam and that only gets you so far. They did however deliver on what they were supposed to do and that was to increase top end power for a more track focused output. Power went from 201bhp to 224bhp on the same boost with a bigger spread of top end power.
On paper they're a 288deg cam but when you look at the timings at 0.050" lift, they're down to 208deg. Couple that with them having only 8mm of lift valve, (7.75mm at the valve), they're nothing special. The engine is doing extremely well to make the power it does IMO.
Just to add a comparison, a 256deg Tomei Poncam seems mild but measures 212deg at 0.050" and 8.35mm lift.
I have a set of cams already ground for this engine, which I am looking forward to trying out but I want to know how the current cams are timed in, so I have a known data set to work from. Profile wise, my own grinds are 272deg but have more duration at 0.050" and a much better lift profile. From my NA days the CG heads fair very well, even as standard, with 9mm or so of lift.
I'll also add, that I've just received a set of detailed cam data from Tighe cams over in AUS who are one of the few companies that offer custom cams for the 4efte. Aside from a difference in lift, (9mm vs 10mm in my case), they're identical.
Throttlebody all stripped down ready to send to Mark at Tornado Systems for a 48mm butterfly. It's by no means my ultimate intake for the CG engine but it's cheap and will bolt-on to eek a bit extra out of the OEM setup.
Another little update. Just got off the phone with the company who is carrying out our cylinder head flow testing. The jig arrived this morning for the head so, aside from a bit of fiddling, the head will be shortly ready for flow testing.
In order to make this extra interesting, I now have a standard CGA3 head which I will be dropping off in the next few days to be cleaned and flowed along side our modified head to provide a baseline.
I will happily post up standard cylinder head flow numbers here, so the community can see what the potential is for using a standard head and what can be expected from a flowed head. This will help to serve as a 'yard stick' so to speak which will help people make informed decisions with respect to power expectations and cam profile selection (for those that are interested in taking that route of course).
Demon Thieves order arrives this morning in the form of a cylinder head component organiser and a set of cylinder head stands. This makes stripping down the head extremely simple and should serve to stop parts walking off anywhere.
So, the spare head is all up and ready to remove the springs, valves and retainers as soon as my removal tool arrives. Yes, and the thermostat housing too
Thanks to Charlie at Surrey Rolling Road, I got hold of a re-scaled copy of our last dyno printout last time we had the turbo Micra up on the rollers. Amazing that this was all the way back in October 2017!
In terms of output the new hybrid turbo only came in 100rpm later the standard GT2554R that it replaced. Considering we didn't bother to do any tuning, (there's a big lean spot around 3500rpm), the difference in boost threshold and spool is more than acceptable.
Anyway, this sets the standard to beat for next year