New Personal Best with 1837

[GSTwithPSI]

I got a chance to take 1837 back to the track last night. It was a packed house, which meant I only got 2 runs in. I was staged for my 3rd run, and somebody broke at about the 1/8 and they closed the track for the night. But, even with only 2 passes, I was able to run a new personal best of 13.5 @ 102, so I can't really complain.

The car was running on 93 pump at about 20psi, dropping off to 19psi at redline. Timing was set fairly conservative, peaking at 17-18*.

I definitely need some more seat time with the new clutch. I'm trying to find the sweet spot with the launch RPM, and I don't feel like I got enough passes to truly find it. I can definitely say this clutch is wayyy better than the old one. I cut my best 60' to date the very first pass. I probably would have had an even better launch if the fuckin' staging official didn't make me drive through the water box. I also need more boost. I'm running ECMlink boost control, and even with the solenoid duty cycle set at 100%, I can only get 19psi at redline. So, I need to screw with it and figure out how to get more boost up top.

My real issue is my transmission. It's just getting worn out, and shifting at high RPM is becoming a chore. So, the next step will be acquiring a decent transmission.

Overall, it was a great night. I got to meet sonyslave from T00ners and check out the bad ass twin scroll S362 setup he's running on his 1G. I ended the night with pancakes at Ihop with one of my other buddies. On the way home, we went through a sobriety checkpoint, where I met probably the only Maryland State cop that knows what a Galant VR-4 is. We chatted briefly about the car before he waived me through /ubbthreads/images/graemlins/smile.gif

 

[faqinshiet]

Great job! If I end up in Va next year I'll have to meet up with you for one of these!

 

[Olson]

cute time.

 

[turbowop]

Michael (sonyslave) was a PNW guy until he moved out there. Cool that you met him. Small world.

 

[GSTwithPSI]

Yeah, Michael said he knew a lot of the guys from English. Said he raced with them back in the day. He's a cool dude, and his Eclipse is pretty nasty.

 

[vr4hotness]

Nice what mods?

 

[GSTwithPSI]

Thanks. You can check my showcase for an up-to-date mod list.

 

[prove_it]

You could run low 12's on a 14b if you were in Hawaii....

LOL


By the way your boost tapering off at high rpm could be the wastegate cracking open and not holding. I had that with my internal S16, no matter what I did I couldn't go above 20psi at above 6500. Even with the wastegate disconnected.

 

[CutlassJim]

Shim that wastegate and run 25 psi like a boss.

 

[prove_it]

Problem with shimming the WG is that it leads to wear on the arm bushing and increases the chances of cracking the turbine housing. It works, but Justin over on tooners found a way to use a holset actuator on the stock MHI turbos. Gives you a 18psi spring can be had for cheap.

Justins high boost solution.

 

[transparentdsm]

seems simple enough, i like the idea.

 

[CutlassJim]

Quoting prove_it:
Problem with shimming the WG is that it leads to wear on the arm bushing and increases the chances of cracking the turbine housing. It works, but Justin over on tooners found a way to use a holset actuator on the stock MHI turbos. Gives you a 18psi spring can be had for cheap.

Justins high boost solution.



The "issues" that you listed, of which I would love to see some proof of, would still exist with a Holset actuator.

 

[iceman69510]

Quoting CutlassJim:
Shim that wastegate and run 25 psi like a boss.



Not familiar with this. Where do you shim?

 

[CutlassJim]

You shim it under where the wastegate mounts to the compressor housing. This raises the seat and opening pressure of the wastegate by shortening the spring inside the wastegate and raising the force required to move it via Hooke's law F=-kX. It's the same as the old school mod of threading the wastegate arm and shortening the arm.

With no boost controller and 1/8" of shims (two washers) I usually see 17-18 psi on an Evo 3 16G base pressure and use a Hallman to control a steady 25 psi. This is with the larger flapper door.

I've been doing this for about 15 years on everything from Grand Nationals, MKIII Supras, 240's and DSM's and never had an issue.

 

[prove_it]

Good to hear. I've never personally seen the wear I describe, but have learned it through a couple reputable turbo builders. In the past I too have threaded the rod and shortend it.

Nice thing about the holset is that they will hold back 30psi. The stock MHI will have a limit as the spring is still weak. Also it will have more throw than the shimmed/shorter MHI actuator(not a big deal as your trying to hold it closed).

 

[iceman69510]

Thank you both. I understand.

 

[CutlassJim]

Quoting prove_it:
Good to hear. I've never personally seen the wear I describe, but have learned it through a couple reputable turbo builders. In the past I too have threaded the rod and shortend it.

Nice thing about the holset is that they will hold back 30psi. The stock MHI will have a limit as the spring is still weak. Also it will have more throw than the shimmed/shorter MHI actuator(not a big deal as your trying to hold it closed).



I can see the bushing wear but have NO idea how this could affect the hole cracking any more. My point was that if it happened with a shimmed stock actuator it's still going to happen with a Holset or whatever regulator as force on the flapper arm is force on the flapper arm no matter how it's created.

I'm not in the elite or an E85 user so I'm not looking for more than 26ish psi out of an internally gated turbo anyway but a I could see a stronger spring being needed after that.

 

[G]

Interesting. I run a e3b16g @ a steady 24psi with out a shim. No spikes, no tapering off etc..........I wonder what would happen if I shimmed it. I could just turn the boost up. /ubbthreads/images/graemlins/dunno.gif

 

[prove_it]

Cams, exhaust, intake all can effect that.

 

[CutlassJim]

Also the larger flapper door gives more surface area for the turbine pressure to push on and they blow open easier than a stock flapper.