Widebody R32 - Gtr Challange Build By Unigroup

[Unigroup]

  On 08/05/2012 at 3:45 AM, FST513 said:

Loving this! Yavuz an actual tuner/ (owner?) of Unigroup posting on the forums and giving people helpful insights.

Thanks for posting this Yavuz and i hope to see more content from you. Greatly appreciate it and the in depth stories. Not just we changed this for this. it's better. why? because it is. the end.

Keep it up mate!

If people are enjoying reading it, then we'll do our best to keep it going. Thanks for the kind words.

Yavuz.

[Unigroup]

  On 08/05/2012 at 11:33 AM, GTR_JOEY said:

Good stuff Yavuz, would love to see the before and after dyno graph with the cam timing adjustment...

Maybe a video of it screaming On the dyno... Just get Oporto boy to make a video

I don't have any before runs but there are more dyno graphs on the next post. It would be great to get a video, but first need to get hold of a camera with a decent mic so it doesn't clip. The sound turns to mush which is half the attraction.

Yavuz.

[Unigroup]

Update - This one is not going to end good…

Last dyno session was stopped due to radiator neck leaking. It's all fixed. Plus we were forced spend nearly a full day on the car going over other things. We had to sort out electrical gremlins with sensor supply voltages, re-wire low oil pressure cut off, plus other things…It hasn't been a fun day.

We've fitted a set of recessed tip spark plugs. These plugs are quite cold (9 heat range on NGK scale). These plugs are worth a try if you have an engine that is prone to engine knock.

I've looked at the engine logs from the dyno a little closer. The exhaust manifold pressure is still lower than intake manifold pressure (29psi vs 27psi & 22psi vs 14psi). It can be beneficial to to try more overlap in cases like this. Higher pressure intake clears the chamber and forces the exhaust out. In turn you get better cylinder filling, and more power. Hence I've got extra overlap dialled in and hopeful for better results than last time.

Here we go, on the dyno again, fingers crossed I just want it finished this time.

Low boost runs to warm everything up is good. I can't wait to turn the boost up to see what it will do. Here comes the big run.

Engine does not sound happy and the run is stopped early. We have water out of the radiator again. We're back to the original theory. The head seems like it's lifting.

Good result, better power at same boost as before. 540kW at just under 30psi.

We spend some time checking everything, and decide give it less boost to test the problem.

Power is up everywhere on lower boost. 530kW now on 27psi (2psi less than before). On 22 psi engine is up 20kW.

But we still have the problem with keeping water where it should be. In theory this engine is built to handle boost pressure similar to what most of us put in our tyres. So we have a problem somewhere…

I'll see what we can do about the head lifting. The biggest problem is time available. To make matters worse, we already have a full day tomorrow.

Yavuz.

[34GeeTeeTee]

Awesome to see a different approach to car building, love it!

[Unigroup]

  On 08/05/2012 at 11:28 PM, 34GeeTeeTee said:

Awesome to see a different approach to car building, love it!

Thanks!

I had a look through the list of mods in your signature. Looks impressive.

[Unigroup]

Update

After a full day at Unigroup, we stayed back at work to see what we can do about the problem. There is no time left at all to finish the car unless we have tons of luck come our way in the last minute.

We've checked the tension on the head studs. We're hoping to find some of them loose below spec. No such luck. They are already tight, there isn't even the room to put more tension. This is the final straw. Sadly there's nothing left to do in time.

I spoke to Julian (owner). He's not 100% sure (it was a long time ago), but thinks the head was put on re-using the old head gasket. It was due to last minute repairs and the right part was not available. So it lasted surprisingly long considering the power levels. The engine also has done a lot of hard running since. So the engine doesn't owe us anything, we owe it.

So what's next?

New head gasket - We still have more boost to come. We also have a nitrous system, which has never been turned on. We need the head gasket 100%. There's going to be some serious cylinder pressures.

New turbo - This one makes me excited. Engines, heads and cams changed little compared to turbos in the last 5-7 years. Easiest way to make more power is running modern, more efficient turbos. I'm guessing close to 600kW at similar boost levels.

New cams? - We're thinking of going back to a smaller grind. The current 280s only made marginally more power if any extra power. It's hard to compare as the cams were not the only change. The smaller cams definitely drove better, had more midrange and bottom end power. When you only have 2.6ltrs on a car this weight, you can feel every kW lost in the lower rev range. The plan is to keep the car street friendly so it can be driven. This is not a race car build.

Cheers,

Yavuz.

[Deano 1]

the pics are abit small, can i ask how high are you reving this thing???

[GTR_JOEY]

Shame about it not making it to the drag battle.. You shoulda taken mine for a run...

Next year will be a good year with Pauls, steves and mine going down for some UE rep

[NYTSKY]

Big fan of these types of setups. Well done to the owner and Unigroup.

[NYTSKY]

  On 13/05/2012 at 9:59 AM, Deano 1 said:

the pics are abit small, can i ask how high are you reving this thing???

Just under 9000rpm.

[N1GTR]

  On 13/05/2012 at 11:50 AM, GTR_JOEY said:

Shame about it not making it to the drag battle.. You shoulda taken mine for a run...

Next year will be a good year with Pauls, steves and mine going down for some UE rep

[Unigroup]

  On 13/05/2012 at 9:59 AM, Deano 1 said:

the pics are abit small, can i ask how high are you reving this thing???

Sorry about the low quality pics.

To answer your question, we're revving to around 9000rpm, and trying to stay as far below that as possible for reliability. I feel that the cams are not the best choice and the engine wants to make peak power beyond 9K. The cam timing ended up rather unusual to bring peak power rpm lower. We're just about out of adjustment as the valve will hit the piston if we advance the inlet cam any more.

Yavuz

Unigroup Engineering

[Unigroup]

  On 13/05/2012 at 1:08 PM, NYTSKY said:

Big fan of these types of setups. Well done to the owner and Unigroup.

Thank you.

The engine is receiving a new head gasket and turbo. It will be ready to run again in approx 4 weeks. Waiting on parts to arrive.

Yavuz

Unigroup Engineering

[Unigroup]

  On 13/05/2012 at 11:50 AM, GTR_JOEY said:

Shame about it not making it to the drag battle.. You shoulda taken mine for a run...

Next year will be a good year with Pauls, steves and mine going down for some UE rep

We should have just went down, however there was a lot of pressure to stay back and catch up on work.

Next year we'll make a better effort. I'd like to get together some cars and go down.

Yavuz

Unigroup Engineering

[Pezhead]

Wow great thread Yavuz! On the video front I can bring in two cameras + go pro to put something together for a single run, say after work sometime. Getting good sound is always difficult because cars like this at full noise are way over the normal db limit of most mics. Best to have an separate external recording - even an iphone farther away so that it isn't blown out as db goes over the limit.

I did some youtube videos from the SAU dyno day - Steve-O's car & Mine. (My equipment and skills have gotten a lot better since then).

[SRS13]

Hey Yavuz great to see you on the forums mate (John Hanna).

Just saw this and enjoyed the read. Sorry to hear about the drama and a shame you couldn't make the drag battle but it sounds like exciting times ahead. Hope it all goes well.