Update and improvements on my Oxy build

[grelland]

thanks for this, I see they have IDA pattern as well

Yes, makes intake manifold choices easy

[grelland]

Time for some updates

I got the engine finally assembled and have taken a few test drives the last couple of days. No fires so far

I have struggled a bit with the tuning, as the engine characteristics have changed quite a lot, so my fuel MAP was way off. I was running in so-called ITB-mode which combines TPS and MAP signals as load in the VE table, and this was no longer very representative for the current engine.

I saw that I have a lot more noise on the MAP signal than before also, so decided to use so-called alpha-N mode which only uses TPS signal as load, and within a few minutes with the auto-tune, it ran decently.

Some fiddeling with the idle, as I had WAY too much fuel at idle, so once I started leaning it out, the rpms went up to about 2500. The cable based throttle system is super-easy to adjust

So now it runs "ok"; it needs a few more miles with auto-tune and then some smoothing of the maps, but so far I am very pleased.

pressure and temps also seems ok

I still have some problems to get it started though. Worse when hot, so I think I will replace the starter motor first, and see if that helps. It is probably 40-50 years old... I already replaced the battery.

I can soon plan a dyno session, and it will be interesting to see how that goes. It certainly feels a lot quicker than last year already.

[grelland]

Replaced the starter yesterday, and that was indeed the problem Now I can take it for longer test drives without my son following me in another car

[grelland]

No major incidents lately, and the tuning is making the engine respond better

I even took the Ghia to work today, so confidence is getting higher.

jobb juni.jpg

I still have some synchronizing issues right off idle, but it is getting better, and I must say the engine runs WAY better than last year. Cant wait to get on the dyno to see some numbers.

[andy198712]

great!!

i had the same deal with ALPHA-N, speed density was "ok" but TPS tune was better for ITB's in my limited experiance on GSXR bodies. they don't give a good map signal and its jumpy too.
i'm actually going back to single TB behind the 911 shroud with a small plenum.... sound familiar?

[grelland]

great!!

i had the same deal with ALPHA-N, speed density was "ok" but TPS tune was better for ITB's in my limited experiance on GSXR bodies. they don't give a good map signal and its jumpy too.
i'm actually going back to single TB behind the 911 shroud with a small plenum.... sound familiar?

Hehe sounds familiar, yes

I would consider a centrally mounted TB again, and I am having some thoughts, but I need to get this setup running first. The main reason why I abanoned my Porsche fan setup was that I had a cheap shroud with no internal vanes in it, so I wanted a better cooling setup. If I could combine good looks with T1 shroud, single TB and performance to match the 160-180 bhp in my 2110 oxy, I would be happy Biggest hurdle is the alternator placement imo.

[grelland]

We were going on a local sportscar event on Wednesday, but on the way there, a dreadful noise developed, and we turned around, and headed home. It turned out that the plate behind the alternator hade come loose, so the fan hit the shroud. Thankfully a small issue, but noisy..

I have been having som small oil leaks here and there, and a fried tipped me that the GB breather box might not be optimal, so I took the top off it and had a look inside the inlet to the filter foam:

åndehatt.jpg

And this small opening is WAY smaller than the original system with a 12 mm and a 19mm hole that vents the case.

So to improve a little bit I removed the inside tin entirely, so now there is a 23mm opening into the foam filter, so it will be a lot better at least:

hattinnmat.jpg

hattskum.jpg

So I hope this will be better until I find a more permanent solution.

So this is how the engine looks at present:

motor 2018.jpg

I will be making some improvements still, but now I just want to drive this thing

[grelland]

Long time and no updates ;( Sorry for that.

The summer has been quite busy with work, holiday and other priorities, but sume things have happened to the oxy-ghia also, and I will attempt to wrap ut the status here.

I was not too happy about how the engine ran, and I had some issues with some injectors that died on me, and once that was handeled, it still seemed like I had some vacuum leaks. A little fiddling with gaskets and making sure the manifolds did not interfere with the cooling tin, and then that was also sorted.

Still I had popping and banging issues, and since I drive the car daily, I started also to moitor the fuel coinsumption. Not that I am overly concerned, but I figured that this may give me some hints as to whether there are some serious problems. The first couple of tanks showed consumption in the 13 mpg range, so something was clearly not right.

After verifying that there were no leaks, I adjusted the valves and I suddenly had a new car Popping and banging disaapeared, and the engine ran very smooth. Also the mpg improved, and for the last couple of tanks I have been in the 26-27 mpg range. Which I find acceptable given my heavy right foot

Here's a plot of the consumption over time the last few weeks:

mpg.JPG

The little dip in early september is due to a long trip on a motorway at 70 mph and 8-10 pulls on a dyno; More on that in a minute

All in all the engine is beatuiful; pulls strongly at lower revs and also has a good bite at higher revs whenever I feel for it

I spent some evenings tuning, and I sstill run Alpha-N as I had scheduled a dyno session, and did not want to start from scratch on the tuning, but the plan is to try out speed density again as I think the driveability can be further inproved still.

In preparation for the dyno test, I also 3D-printed a set of quite long velocity stacks to see if there was a measurable difference between those and the filters I was using:

trakter.jpg

After some fine tuning of my MAPs it was time for dyno testing, and this was quite intimidating to watch (and hear):

ruller.jpg

It is quite loud at 6500 rpm inside a smallish garage

[grelland]

The result from the dyno run was this:

curve.jpg

And that was quite as expected. 127 hp on the wheels, which is in the range of 150 on the flywheel (on this dyno....) and nice and flat curves.

Also worth mentionning is that the tuner guy tried adjusting both fuel and spark to see whether we could gain a bit more, but any changes he made resulted in lower power, or more narrow power band, so my "seat-of the pants" and Auto-tuner sessions has worked real good

The velocity stacks gained about 5 whp and 15 Nm over the filter across the rpm range, by the way.

So now I am just enjoying the last few weeks of the season and this brings a smile on my face when going to work every morning:

front.jpg

[george2490]

Nice work!

Sent from my SM-A320FL using Tapatalk

[Steve Arndt]

Beautiful car.

[grelland]

thanks guys

[andy198712]

So great results there, lovely power and torque curves!

i was waiting on the update

so the question is, is the that 5bhp and 15nm due to the restriction of the air filters or the design of the trumpets?

[grelland]

so the question is, is the that 5bhp and 15nm due to the restriction of the air filters or the design of the trumpets?

Glad to see you follow this

I am not sure, but I discussed with the dyno guy the possibility of making a series of runs where I use a number of different length trumpets and also a couple of different versions of filters.

The 3d-printed parts would make that "easy" from a technical point of view, but I am not sure the data/information I get is worth the investment. Dyno time is not particularily cheap.

I know the results would be of interest, but I am wandering whether I should be the one paying for that

[andy198712]

so the question is, is the that 5bhp and 15nm due to the restriction of the air filters or the design of the trumpets?

Glad to see you follow this

I am not sure, but I discussed with the dyno guy the possibility of making a series of runs where I use a number of different length trumpets and also a couple of different versions of filters.

The 3d-printed parts would make that "easy" from a technical point of view, but I am not sure the data/information I get is worth the investment. Dyno time is not particularily cheap.

I know the results would be of interest, but I am wandering whether I should be the one paying for that

i would be thinking the same thing! car runs great and makes great useable power, why waste money.... enjoy it can't wait to get mine back out on the road!