4 FOX SNAKES - Ross' 20vt 4kq

[WOMBAT]

Lookin good Matt! I need to grow some balls and dig into my own tuning.

[bradyzq]

I think this thread needs updating.

[themagellan]

Well I'm happy to report that with the drain on the catch can I have 0 oil spraying in my engine bay. Effin love it. I have also started to very slowly increase timing. I'm up to 1 degree less than Marc's base map above 100kpa, and using a less aggressive timing retardation map at 50*and under. Pulling 0* at 40c, 1.5* at 50c, and 3*+ after that.

I'm also going to work on my spool a little more, I removed a bunch of fuel down low as it was just TOO rich. I may go through and set my WG spring again as well just to be sure it's all right.

Sorry, but could you post some detailed pics of your catch can setup? Can't wait to pick up a VEMS unit

[chaloux]

Well I'm happy to report that with the drain on the catch can I have 0 oil spraying in my engine bay. Effin love it. I have also started to very slowly increase timing. I'm up to 1 degree less than Marc's base map above 100kpa, and using a less aggressive timing retardation map at 50*and under. Pulling 0* at 40c, 1.5* at 50c, and 3*+ after that.

I'm also going to work on my spool a little more, I removed a bunch of fuel down low as it was just TOO rich. I may go through and set my WG spring again as well just to be sure it's all right.

Sorry, but could you post some detailed pics of your catch can setup? Can't wait to pick up a VEMS unit

Will do. Just have to take them. It's very simple though... 1" hose off stock breather port on block, catch can, 3/8" drain to a barbed fitting I tapped/threaded into the oil pan.

I think this thread needs updating.

Soon, soon! Just got home from work. Got any data for me?

[bradyzq]

Working on the dune buggy.

I'll get it out of the dyno computer this evening.

[chaloux]

Merci! I'll have a proper write up tonight. Maybe. I might have to go to bed right now, lol. I'm so tired.

[chaloux]

Well I have no time, but long story short the car made 315wtq and 360whp at 23psi, tapering to 20psi. 94 octane fuel.

It's too bad, there were a couple issues that took a lot of time and really slowed us down getting things rolling. But once we did things went smoothly!

Interesting points: my mat sensor appears to be off, reading high.

The new r59 plugs I picked up from Marc made 20whp more on exactly the same tune vs my old bkr7eix.

This car needed timing in a very bad way. Making way more power on less boost than before.

I'll post up my new iat timing pull table. How hot would the exterior of the intake manifold be relative to the intake air temps?

[bradyzq]

Gaaaa! Pdf images not supported? Oh well. Here are the dyno curves as regular attachments.

[mushasho]

Cheers bud!...

[chaloux]

Okay so here's a full write up. I'll try to be quick

I arrived at Brady's at 4 on Saturday, thinking I might have enough time to give the car a quick tune before dinner at 8. Well, he was balls deep in a RWD Skyline that had several hiccups and were finally starting to "turn up da boost!" as the very french owner, Max, put it. The car ended up making 460whp and 400wtq on a cast 3071, I'm not sure what boost. Very quick car... "TABERNAC!"

So I stayed over at Brady's instead of Don Smith's place (of QW fame). Dad met us at the shop in the morning and we had the car on the dyno at about 11. But then the keys were locked in the trunk... damn it! So I need a new trunk locking mechanism now. Once that was done, we found out the center diff had to be locked, and of course my vacuum doesn't work. So we jacked the car up and pulled it into lock manually, and then zip tied it.

Did I mention dad and I were supposed to go to the race at 2? When we finally had the car working right on the dyno, it was 2:00. Ugh. So we skipped the race, which we thankfully didn't already have tickets for.

The car made hilariously crap power on the first pull. The timing pull was absolutely killing it. 10 degrees is not enough to make any decent amount of power with. So we started to investigate with a temp gun and found that the IC outlet was only hitting about 45, and the intake manifold was only around 45*C as well. So we pulled the MAT sensor, and in a 30*C room it was reading a minimum of 39 after putting a cold wet paper towel on it. Then it went back up to about 41. So at least at 30-40*C my MAT sensor is 10* out. We shifted all the cells in my MAT timing pull table one to the left, then deleted the -40 cell because WTF and added a 100* cell. There were no signs of det at 85*C intake temps with about 19* of timing up top (two degrees removed I believe). That's when the car made 360whp. BUT, on the street, I wasn't able to get the intake temps above about 55*C, I believe the added spark probably helped bring them down if anything.

So that's timing... fuel was good, only minor changes which I then had to change a bit later on the road. A little here, a little less there, etc... no biggie.

Boost. Well, as you can see from the graphs, the car made way more power with timing at the same boost than with less timing. Obviously. But just for comparison, below are my wastegate pressure pull, which creeps (I then took 3 turns out of the WG and we enabled boost control), and the final power pull. Power/tq and boost. We were out of time and had to call it quits at 23psi. We had a 7+ hour drive ahead of us and it was 6 by the time we left Brady's. We tried upping the duty cycle a little, and it yielded no power gains, but also almost no boost gains if I recall. At that point as well, the IAT table was pulling a little more timing so I think that negated the MOAR BOOST. BUT, I think now, out on the street if I add some boost it WILL be faster. I think I'll go back to the 285kpa I was running before, it's just too bad I couldn't see it on the dyno. The only thing that makes me doubt it would make more power is that it didn't on that one pull, but I think that was a MAT/Timing thing more than a more boost not doing anything thing...

One strange issue I am now having is that after a hard pull the engine will just die. I have a VEMSLOG which I haven't looked at yet, and the ECU stays on. So something else is screwing up and turning everything off. It will not restart unless I flip the switch thatt powers the relay that powers the ignition, ecu, and injectors. I will start there and move on. Brady suggested EMF from the coils which sit right on top of the ECU (separated by the rain tray metal). I'll check that out too. It's strange, it seems to do it nearly every time. I'm not sure if it's 7krpm that does it or full boost or what... but it just does it right after a WOT run as I lift.

SO, am I happy? Yes... the car feels SO good now, at places I gained 90WHP!!! On the highway is where I really notice it is FAST, in 1, 2 and 3rd gears the torque is enough to make the car feel fast. But now it really picks up and goes, speedo says so too... Of course I wished for more power, I think 375whp is a really easy target. But I am very confident with another 2psi and leaving everything else as is, it should be very near that figure. Also, my car was pulling timing on the 360whp pull which it doesn't do on the street because of better IATs. Brady is the man, I HIGHLY recommend hitting him up if you are looking at making some real power. Street tuning is great but there is nothing like timing on a dyno.

4fox boost.jpg (272.58 KiB) Viewed 25360 times

4fox pwr tq.jpg (281.49 KiB) Viewed 25360 times

[loxxrider]

It's all in the timing isn't it

[chaloux]

And max's vid: http://youtube.com/watch?v=KLC-5zbymcI

[chaloux]

It's all in the timing isn't it

it seriously it's, in a big arse way.

[loxxrider]

I WILL have an R32 GTR. It's in my top 5 all time favorite cars! Well, I like a lot of cars, so maybe top 10.

[PRY4SNO]

Looks like a solid improvement!

[chaloux]

I just had an "AHA" moment! These plugs are not resistored and the relay that powers all that stuff that makes the engine run is about 6" away from my coils... Coincidence?

[mushasho]

"aha"...

[chaloux]

Fixed it.

[dana]

i remember when marc was street tuning my car, the difference of 1 degree of timing was very noticable. Excellent numbers Matt!

[mushasho]

But I am very confident with another 2psi and leaving everything else as is, it should be very near that figure. Also, my car was pulling timing on the 360whp pull which it doesn't do on the street because of better IATs.

Are you comfortable bumping up the boost like that on pump fuel?

[85oceanic]

AWESOME Matt! I bet the car is a total blast!!! Now go find yourself some E85 and you'll be ruined.

[Hank]

Nice Matt

[chaloux]

But I am very confident with another 2psi and leaving everything else as is, it should be very near that figure. Also, my car was pulling timing on the 360whp pull which it doesn't do on the street because of better IATs.

Are you comfortable bumping up the boost like that on pump fuel?

Sure. I was running 26-27psi at Carlisle. No power but lots of torque/grins Only 23psi in that graph.

On 94octane with solid timing, fuel, and the right timing pull... and I'm going to make some knock phones... I don't see why it should be a problem at all. There are many who have and run 28-30psi on 30rs without an issue, and it's "cold" up here. I'm going to consult with brady and the knock phones and go from there.

[loxxrider]

I don't think he's got anything to be concerned with as long as the timing tune is a good one.

[amd is the best]

I ran 28psi on my stock block 30r on pump fuel FWIW. Maybe not with a ton of timing but it handled it.