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

I get my info from the English B13 FSM which includes Pulsar which naturally includes the SR20DET from a GTI-R

Now if only I could find the Avenir or Bluebird FSM!

-G

Oh no my mistake was not even not taking it to the dyno. It's not getting a tubular manifold from day one. I have heard very mixed opinions about that one. Some people warned me about VE's and Log's, but then I listened to people whore are more knowledgeable and they said logs are just fine, accept the part about very specific tricks being required was left out.

I also still don't like how slowly this turbo spools. Perphaps once I can use the bigger lobes it will spool faster? The turbo is just too laggy for low boost and such a fat car. If I were too run more boost it would be better, but there is no way I will even dare to run more on a log manifold.

What I'm getting at is, even if I hit my goal whp, 300whp, it would be all peak and not much down low. I really only care about low end power and torque because this is a daily.

The ve will hold boost just fine tuned right. Even with the 12lb spring in your external gated t28, you will have no issues if tuned right. That will put you at around 300 or so whp, still have good gas mileage and have a responsive setup. Why would you bother to go external gate and run 6psi? I think the 12 psi external gate setup may even yield more than 300 whp just because of the external gate. If you have 93 octane, throw that 6lb spring in the garage somewhere and forget about it, such a waste of the turbo, the intercooler and the external gate. Don't worry about throwing rods out or any of this nonsense i am hearing about the ve. I have seen stock ve's holding more boost than we are talking about here for a long time and a long time ago, all while making amazing numbers on even old school turbos. This is not new stuff. The external gate should help keep the temps down and since you won't run more than 12psi, the turbo u have is perfect. Tuning tuning tuning. Boost the VE, tune it and run the 12psi spring and don't look back. Stop with this 6psi nonsense and the need to swap bottom ends. We are talking minimum boost here with and intercooler, a tuneable ecu and an external gate.

This was taken from your det vs ve+t thread and was one of my quotes. I don't remember me or anyone else telling you to go with a log manifold. I did however say in this thread that a log will be just fine as I have seen it done. I would have used the external gated t28 over the setup you chose any day. But you chose what you did for whatever reasons they were. The setup you have can work, you need to get it on a dyno and tune the damn thing. It seems like it is too late at this point. I agree a tubular mani is better than a log in every way but the fact is that the log can get it done. You can believe me or not, i don't care. You should really consider who you take advise from in the future. Talk to sr20Gtir about the tuning aspect of your setup. He has tuned many setups that made great power. If you were looking at 300whp from the beginning the external gated t28 was a perfect choice.
Drew

I would even pick a stock manifold/T28 setup over the log manifold setup. Any day. But to put it simply, a dyno isn't going to fix it. It just isn't. That's where I disagree. No amount of tuning is going to fix the issues with reversion that you are seeing.

Go tubular, and that will fix most of it. Or save your money and setup and go VET cams. I would spend the extra money and go tubular. You will make more power that way with less boost.

A log can make 300whp. I won't dispute that fact, as I got closer than I thought on my setup. A disco potato on a stock manifold would perform better than a log. And it isn't a surprise why. The stock manifold separates the exhaust pulses all the way to the collector.

I could send you my injectors/maf/ecu and you could try that and experience the same thing. I'll have to stand on the other side of reason on this debate, and live with my "theories" on what is going on.

We can just agree to disagree, I am fine with that. I agree that a log isn't the best option but it is doable. I also agree that the external gated gti-r setup is a great option and makes awesome numbers on a ve with stock cams. If i were Vadim, unless you already sold the gti-r setup, I would use that and sell the log and the larger turbo. For what goals he has set, the gti-r or larger t2 on a gti-r manifold with external gate would be ideal. I would rather have a quick spooling setup with a large power band personally than a huge power, later spooling, higher revving setup. His goal was 300whp reliably with decent gas mileage without having to build the engine. He had the setup to do it and maybe still does. He would need to re-do the piping but with what he can recover from selling the log, the only issue would be the extra work. I would do that rather than go and spend a ton on a tubular manifold or different cams. A gti-r setup is great on a ve-t especially with an external gate. Seeing as how he isn't looking for huge power, that would be my choice. I am done arguing whether or not a log will work and am trying to Vadim back on the right path. When he has that setup, I don't think that spending all the extra money on a nice manifold or new cams is necessary. Will it make better power? Of course! Will it cost a decent amount of money? Of course! I think that using a large turbo for 300 or so whp is a waste. It should help keep temps down but at the expense of spool time. Unless it is a track (drag race) car, I would rather have a quick spooling turbo that makes decent power. An external gated gti-r setup will keep egts down also and make over 300whp no problem. No matter what setup, I think it should be tuned on the dyno when running a stock ve.
Drew

For sure on the tune. I hear where you are coming from now. A tune is a good idea on a dyno. I just don't think it will fix the issue.

But the cost of swapping cams is just as cheap as swapping out all the parts to go back to the GTiR setup. Prob the cheapest option. And spool time will be really good too. Look at what I've done with my setup, and now it spools better than a GT2871r setup.

I would say the old setup would be a way to go also. Just say no to the log manifold... unless running a bigger turbo.

totaled200ser, I think you may have missed a few posts, I have been running 12 psi for a while now. Since end of July probably. The turbo that I have, as mentioned by a bunch of folks, is laggy but then comes to life after 6psi, and since I cap it at 12 psi it's not reaching full potential. I would need to spool it to 16-20 psi to really get decent power out of it. The problem is on a VE with stock internals and compression, I will run out of timing to retard at 15 psi probably.

The motor is still working fine too, we are just catching early signs of detonation. That's telling me if I don't do something about it soon then it will be gone. I will have to retard my timing yet again, and go back to the NA feeling car until I get a new manifold.

I went with the top mount because it was a more drop in alternative then with the bottom mount. My GTiR T28 would run out of breath at 320whp. Running the turbo at that daily would probably kill it fairly quickly. I have an external gated GTiR manifold that is ported to the VE head. The next problem is fitment. The external gate flange will dig into my Koyo radiator. Since P11's radiator sits in-front of the radiator support space is a pain. With the bottom mount turbo I would need to make a solid front motor mount. That means a ton of vibrations, I bought an Infiniti for a reason, I don't want to turn this car into what my Sentra was.

I'm about to just make a top mount tubular manifold. I'm just afraid that even with the tubular manifold the turbo will still spool too slowly. I was going to just do VET cams, but seeing how I'm getting knock even with low cams that have 0 overlap, I think I'll still have the same issues.

what special tricks do people do to the manifolds?

[/B]

I have seen and had bad experiences with AEM UEGO. I HAD A CUSTOMER that his car was registering 10.8 but the dyno was saying 11.8. so i went by the dyno reading and when i adjusted it richer the car was doing better. for drivability they were saying the same but under full throttle they differ quite a bit. GL

it also depends on how far away from the turbo you have your wideband. Vadim, if anything you might look into switching your wideband from where you have it to where your stock o2 is and move your stock one where the wideband is. Too far in the exhaust stream will affect the reading with the cooling of the exhaust. When the exhaust is cooled your o2 molecules are more compact and will most likely give you a richer a/f reading.

From what ive seen with my AEM UEGO as long as the sensor is fairly new/less than a year old or so they are pretty accurate with the readings ive seen from other o2's when on the dyno.

I think you need to run it richer under WOT vadim, richer you go, the less likely to detonate and better cooling effects. If i was to tune your car i would put it at 11.2-11.3:1 range from just before peak torque and onward. You should really see a difference in knock resistance when doing so.