Thread: Think I went with too big of a turbo...

LOL- I would also like to know what was said. I have a pretty good idea what it was as I was going to type something that I have said in the past but for the same reason, haven't yet. I will just say that Vadim- once you get your setup sorted out, you will be so happy with the power it is putting down that I don't think you will be worried about changing much besides getting it dyno tuned. That is unless you still want to try for better fuel mileage.
Drew

I will agree with them tubular designs are more efficient than log and make more power at lower boost. But logs could still get the job done one way or another, notice when the Vvl kicks in it was nearly a 100 hp jump when it activated(2.0 cams). I also tested sr16 cams and it raised my powerband I had a rev limiter of 7950 on the Ecu at the time so I could give more rpm's but I was still climbing at 8000 rpm's.
Log manifold.447whp. .63 backhousing

GL on the car,don't give up. Btw lower the timing it's real agressive.

Some updates and new timing map.

Decided to try feeding the Waste Gate from closer to the manifold, teed into the BOV line. I know it's not good for WasteGates to see vacuum, but I have no other lines to tee into . Updated the tune to be safe in case this fixes the low boost issue. Took it for a test run and bam 11.5 psi like the big red spring is rated for.

I'm thinking the pressure drop off might be part intercooler part engine sucking up the while the wastegate line at the turbo still thought it was 11.5psi, especially since it would spike then level out.

Here is my current 10 psi map, I need to update it for 12 psi now...





The only thing is, I'm running a B15 SE disc with what seems to be a south bend pressure plate. It's holding well now, but I don't know how well it will hold above 300whp.

I thought 10.1:1 DE's had issues with more then 10 psi of boost, I would figure VE would be just about the same, thus dunno if 15 psi would be safe.



I wouldn't have bought an OBD1 Real Time ecu and TunerCode if I wanted to look at the tune . I don't think I'll ever stop really tuning it. Maybe once I stop doing physical mods to the car... but we all know how that is with our cars.

Did you map trace the boost transition?

What turbo and AR you running gio?

Vadim, DE's can handle way more than 10 lbs of boost stock. There are people pushing de's to 450whp on good flowing t3 setups. With your setup you should have no problem making 300-350whp as long as you keep the detonation away. Again lower your timing down some and up the boost again just being careful to listen and watch for any detonation.

DE's dont like 15psi from a T25 but thats about it. lol My buddies nx was running 15psi on a gtir t28 without problems. Many people running T3's making 300-350whp without issues even on log manifolds. Its all in the tuning. Cant say the same for pushing the t25 past its limits as no matter what I did it still cracked ring lands past 14-15psi with s4 cams on a de. Just too much backpressure.

You should be fine Vadim. Id worry about that clutch before anything else. 15psi on pump with your setup should be fine and if your not making over 300whp on 15psi something is wrong.

You will see that turbo will really liven up at 15psi and above.

What a/f ratio are you getting under wot. Again keep the mixture rich around 11.2-11.5:1 and you shouldnt have any problems with detonation with about 19 deg timing up top. You could actually add more timing to your low end and then lower the timing on the top end. A turbo map should look kinda opposite of an N/A map when it comes to the low to high end WOT columns. Give it more timing down low to help spool time and gradually decrease as you approach peak torque then flatten out through peak torque and then decrease some through the topend. Whereas an n/a map likes more timing as you get higher in the powerband.

Give it a shot. Hope that helps.

Does the same apply to the UK DE's, aka red top 10.1:1cr ones. I just remember seeing threads where people were saying it's not a good idea, granted it might have been on a smaller turbo like a T25.

I can't data log my AFR's yet, but keeping an eye on them I'm trying to keep them at 11.5. I know its rich, but it gives me a pillow on hot days until I can get all of the cooling system issues squared away (ordered two Spal fans).

I'm definitely trying to increase more low end timing for a better torque response. As for spooling, 12 psi at 5k rpm seems a little late, even though the car doesn't feel lagy. It is a journaled bearing turbo, but the billet wheel should help for something.

Now I need to rescale my TP scales though too, 12 psi hit 100 tp, while before max was 90. Trying to avoid ECU from self tuning in boost maps

maybe im mis understanding something here isnt the TP scale in relation to throttle position? Or is it a combination of throttle and different loads? I guess with your map tracing with Tuner code you can watch and log what it hits during pulls. Interesting. I always though it was just a matter of throttle position and then the k value and stuff tuned the maf and injectors. Which it does but just didnt know that about the map.

Anyways i had a 10:1 motor Vadim and it was good on the T25 until past 14-15psi and then same thing as the 9.5:1 motors. No matter how much timing i took away and how rich i got it which was down around 11:1-11.3:1.

For you 11.5:1 is safe and i would keep it at that or less maybe 11.2-11.5:1 idealy. It really does help. But as far as a 10:1 compression sr or higher its fine for boost man. Just keep the detonation away. Plain and simple.

Vadim did your turbo come with the Stage 5 exhaust wheel like the older SC61 did?

t31 turbine aka stage 3