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

I got rid on my log. went with an equal length. ditched the ac adjusted my timing and wooooooooo!!! WTF>>>>>>

Do what I did. Source some VET cams and gain 100whp by not doing anything else. Otherwise, spend a lot more money on a tubular manifold and see the same gains.

Actually, my data showed that I only gained 20whp using sr16 cams and a tubular over the log/VET cam combo I had many years back.

Its a bent clamp. He just jizzed his pants cause it actually fast now!

I doubt it. Sorry.

If it doesn't feel like you got rear-ended when VVL kicks, then you are having poor scavenging, caused by reversion. Vadim, whats going on?

Some may know my setup, but let me tell you in case you don't know.

GT3076r .63
Protech log
Made 268whp on 16psi.

GT3076r .63 with VET cams
Protech log
Made 359whp on 16psi.

You can see the results by looking at my old threads. I have no hope for a log mani on a VVL without low-overlap cams. It works... just not very effectively. A DE is likely to be much faster with S4 cams. Take 20* of overlap out, and its an entirely different story.

I went to the extreme. I got a twinscroll manifold with a divided housing turbo. Even with a super-restrictive 1.06 T3 housing, it spools so fast the turbo surges WITH a ported shroud. Its so brutal when the VVL kicks, the tach would sweep from 5k to 8800rpm in .5 seconds. Open housing would probably make even more power up top, TS housings are restrictive. Yet I was able to pull ~480whp on 26psi (still very low for the turbo size). I think it would make 500whp on 22psi with a .82 open housing. The VVL just hates backpressure.

explain

He will update later, I was just happy for him!

Coheed, I appreciate your input, simply because I know you have been there and done that. VE-T cams would be nice, but they would neglect the reason for me to go VE (gas mileage on low cams). I also would like to upgrade to a tubular manifold for better gas mileage (Ford upgraded from log to tubular and gained some nice MPG's probably a decade or two ago).

Earlier today I drove my wife's car (same year p11, LollerRocker, SSAC header and BPi Flow stack on a stock rubber intake.) I gunned it on a bad road I drive everyday (bumpy/half gravely), her car actually scared me on how fast it picked up speed. NA VE would be pretty darn quick on this thing too if LollerRocker with two simple mods is feeling fast.

Anyway back to the actual car, got a compressor pumped up the piping, before I could hit 12 psi it was leaking out pretty quickly from the turbo coupler. Turns out the T-Bolt clamp was V shaped in one area (missing a piece), thus it wouldn't seal. I replaced it, with a better one and replaced the coupler with a new one. That sealed it better, but still was whistling Tightened the clamp that holds the first pipe and found another area it was leaking.

Bad clamp on the left


Original coupler on the right, it's a bit too long for the pipe that I have connected to the turbo. This is probably also led to a poor seal.





Finally was able to get 20 psi in, and after that the actual turbo to CHRA connection started leaking. I tightened those bolts but it still leaks at 25 psi.


Went for a test drive, car felt a tiny bit faster but no real difference. Said screw it and started adding timing to the boosted area at 3* increments. In no time the car was so fast that I just about jizzed in my pants, hence Keo's comment earlier .

The turbo still doesn't spool fast, 5k rpm 10 psi boost, now it seems to fall off even more though, down to 7 psi by redline, but the car is much faster at least. Knock sensor is definitely showing knock in some areas, but I think it might be too sensitive, guess I'm going to go by audible knock.

Finally here is the timing map, I took the SR20VE timing map that Calum had (instead of my dummed down VE-T one), and reduced 2* per psi then increased timing by 3* increments in certain areas.

The leak was obviously just a minor problem but I told you on the timing. lol. That timing map looks better. Im assuming you verified with a timing light that your base timing is at 15 deg matching your map correct? If not I would do that as well to make sure. Since you have full exhaust on there you should be able to hear any detonation at all. Ask coheed, he could audibly hear it and if your not hearing any then your good. Our knock sensors are sensitive and create a lot of static noise especially on boosted motors with extra power. Again its gonna come down to what the actual voltage reading back from the knock sensor is. From what ive seen static noise is usually between .3-.7 Volts. Anything above 1 volt is starting to become actual pinging/light detonation, when i had major detonation to the point it broke the spark plug straps i was seeing between 3 to 6 volts off the sensor. Not good. Static noise you will be fine. Obviously the car has picked up quite a bit as you seem excited about it. lol.

Glad you got it figured out.

I am pretty excited, I was worried there is something else that could have been broken, which there still might be with the boost dropping off towards the redline. Maybe the waste-gate is collapsing.

I'm looking at the actual knock sensor voltages, normal operation seems to be around 1-2v, what I'm doing is ignoring the single voltage spikes, and looking for the multiple knock counts at the same time. There are a few cells that had 2-3 knock counts at the same time, which that tells me that it probably did knock after all.

I did the runs at night, where the temps are below 80*F, so will see how she does tomorrow at close to 100*F.


Still not quite there yet, gotta get the lag straight first . Unless this turbo is simply is that laggy,

i was reading through this and glad ya fixed it... i was bout to say. that turbo should rip ass even on 10psi!