My question is what spring rates are you using, what is your max psi with that spring, and what solenoid/tuning software are you using. I want to be able to hit 18psi but have my spring be as small as possible, and if I remember right you only can make 3-4 times the boost of your spring rate. Just want some real examples.

 

I use boost by gear in my crx hondata s300, I think I have a 8lb spring (red spring) with my aem electronic boost controller I have no problem hitting 20-22 lbs on race fuel setup. I dont think It matters too much as long as you have your wastegate setup to hold shut until your boost level is reached. Using both sides of the wastegate and not just the lower fitting for bleed off. How much boost do you want to boost?

 

Not 3-4 times, generally about double. wastegate and maniflold design can change results. I could hit 18 psi on a 8psi spring. I switched to a single precision 39mm gate and can only hit 28psi with an 18psi spring. If 18 psi is your max goal, you should be fine with an 8 pound spring. I wouldn't go smaller than that and 8psi should be fine for first gear

 

My last setup I had a 5.4lb spring.. I was able to hit 16lbs. My goal is 500whp which should be 18lbs. 16lbs hit 462whp but clutch slipped.This year I have a bigger clutch. I guess I will just order big for the retune and after that is done ill have to play with different sizes to get the boost down as low as possible while still hitting my max. I appreciate the replies thanks guys.

 

Ok so 3x spring. How was your boost controller plumbed?

 

what turbo and gas

 

Generally you can get a little over double the base spring at lower boost levels, but anything above 20 PSI, it really depends on the amount of exhaust pressures in the system.

Too soft of a spring, you will also lose boost response between shifts. It's just the nature of wastegates, and soft spring will always creep open slowly and close up slowly. You will definitely feel the difference between a 5 PSI spring stretched up to 18 PSI, versus running a straight 18 PSI base spring in terms of spool and response.

I find it easier sometimes to run a heavier spring (like 15 PSI spring), and use the gear compensation tables and dial out a few degrees of timing for 1st and 2nd gear. It reduces power output by a lot, but I can still keep a heavy spring on there for 3rd-4th-5th gear and not lose any spool.

 

Tony, doesn't it matter how you have the EBC/WG system plumbed?
My goal is to have a 5-30psi spread so I can have traction in 2nd

I have a 5psi spring and was able to get 28psi while tuning EBC duty.
But it was boosting to the moon without any wg control (I hit my boost cut)
It seemed it would either boost 12psi at 90% or infinit psi at 95% duty.
The resolution was messed up but it shows the system is capable of 5x spring.

I never got that sorted out but Id really like to talk to someone who has experimented in this area.

 

Plumbing the vacuum lines definitely makes a difference.. All EBC's work by sending pressure to the top port of the wastegate based on duty %. If the boost pressure source is identical for both top and bottom ports (EBC at 100% max with a high flow solenoid), then the two chambers of the wastegate equals out in pressure, and only physical pressure of the wastegate spring will act against directly to the exhaust pressures to keep the wastegate shut. As I mentioned above, once you get to this point, it is solely based on your exhaust pressure levels at where the wastegate is located to determine maximum solid boost through redline. On a short log manifold and a turbo with a small turbine housing, you will probably have boost falling off at higher RPM's with a wastegate located in at a nice centralized location. On a long runner topmount manifold, big A/R housing, 4" DP and possibly a wastegate placement that is not directly against exhaust flow (wastegate placement not fully prioritized), then it the same spring can allow much higher boost levels but may sometimes creep at its minimum depending on how the wastegate is located.

You can stretch the spring further by taking the boost signal source for the WG top port directly from the compressor housing (highest pressure zone), and then have the lower port receive its boost signal from the intake manifold (or just before the throttlebody) which is the lowest pressure zone. This pressure differential is caused by restrictive charge piping, pressure drop from the intercooler and so forth, but allows more pressure at the top port of the wastegate and assisting in keeping it shut, yet it will not affect your minumum boost pressure. You can also further cheat this by running smaller vacuum lines and fittings for the lower port, but run bigger, shorter line with larger fiuttings for the top port.


What you were experiencing with the infinite boost and the lack of resolution could be due to a plumbing error of the EBC lines, or the turbo/manifold setup you have is really efficient (really low exhaust pressures). But if you are hitting boost cut, you may not have the opportunity to really "ride it out" and see if you can maintain 30+ PSI until redline. A sudden spike will not reveal exhaust pressure factors because there isn't enough time to build exhaust pressure and prematurely open the WG. Most likely, if you did ride it out with no boost cut, your boost will probably fall off almost immediately at upper RPM's and probably drop back down to 16 PSI or so (about 2-3x base spring pressure) once the exhaust system has enough time to build pressure. And depending on how your ignition and fuel maps are tuned, most tuners will safeguard your map against unintended boost spike or creep, and timing will be heavily retarded and dumps extra fuel. This in turn, sends even more energy through the turbo and makes it spool even faster (but engine power is lower and safer due to lack of proper timing and fuel).. It is acting like a rolling 2-step ALS.


If you hear your wastegate opening but boost still increases uncontrollably, then it is due to the manifold design or simply your turbo/manifold is really efficient and the turbo wants to keep going. If you do not hear the wastegate while the boost is increasing uncontrollably, then it is probably an EBC plumbing error (either lines are too long, small, etc..), a sticky and slow boost solenoid, or tuning error (start duty too high), or EBC glitch/error (sensors not working properly).

 

the way to get the most out of a setup is running the bottom of the wastegate to the intake manifold and the boostcontroller to the turbo for quicker responce time out of the ebc. Generall you can see between doubl and tripple the spring rate depending how soft the spring is. Muckman on a 5 psi spring you will not be able to achieve 30 psi . Only possibility to have such a broad range of boost is to run a co2 setup to control the wastegate and that will get costly and is really just a racing thing.

Ive always seen just about 3 times the wg spring rate. IE on a 5 psi spring i was able to achieve 16 psi, on a 7 psi spring i got 21.5 psi and currently on a 9 psi spring im getting 22 psi only 60% duty on the boost controller so im confident i could see 27 psi boost with the 9 psi spring. These were on all different engines and different boost controlle as well

 

You can also install an MBC on the bottom port line to "make the spring bigger" in certain instances...if you install a spring too small you can compensate by doing this.

Or install a second solenoid on the bottom port to "hide" boost from the bottom port of the wastegate in higher gears to help you get a bit more out of it.

I think Mapps was running 4psi springs in his twin gates as was able to get 36 psi out of his setup last year...

 

I was experimenting with the EBC plumbing. I have it plumbed so the EBC will switch the boost reference from the side wg port to the top wg port rather than bleed it off to maximize the controlled boost range.

*Using a MAC 36 series solenoid
port1 - top wg port
port2 - boost reference (turbo)
port3 - side wg port

This method is described in this TurboSmart eBoost manual under "Two Port Connection Method 2".
https://picasaweb.google.com/lh/phot...eat=directlink

 

Hows that working out for you muckman? I know when i hooked my eboost up that way it was called maximum boost setup and it basically kept the wg shut LOL. maybe the eboost2 has different setting assuming that what your running?

 

Right now its not working out very well. As I said above, With a 5psi spring I get 10-12 steady psi with 90% duty cycle and then at 95% duty I hit my boost cut at 28psi lol. I dont know if the problem is 1.) my calibration 2.) the MAC solenoid or 3.) the way I have the EBC plumbed.

From my testing the results sucked. I had to add tons of duty cycle to raise the PSI very little. And then near max duty I had very little resolution. Not linear or consistent at all.

I need to test against a known constant to rule out 1 and 2 by plumbing it like the "Two port connection method 1" which is more "standard". However I ended up bending a valve from that 28psi spike which over reved my engine before I could let off. That was back in the fall.

 

Which boost controller are you using?

 

Im using Neptune to control my MAC solenoid. Do you have any recommendations you can share with me?

 

i would run a 7-9 psi wg spring...

 

I hate to bump old threads but I did some searching and came across this page.

Anyway I have a 83MM GSR, PTE 6265 twin scroll with hondata s300 & MAC solonied. I am running a 11 pound spring as of now. When I bought the dual Tial's 38 WG's it came with all the springs. My goal is to try and run the least amount of PSI that my setup will allow me to so I can get some traction in 1st-2nd gear and & make 30-35 pounds of boost. What would you guys recommend for my setup?

 

Also just found this thread and wanted to see if anyone had similar issues..

I have 5.8 psi springs in both my 44mm gates.. It was seeing 8psi constant without the controller.. When we increased the duty cycle, we could only get 19psi out of the gates..

Is this typically area that the springs get maxed?

 

Well more pressure is because there not setup perfectly on the manifold so it tends to creep some like you were seeing at low boost levels but at 19 psi your more than trippling the boost pressure of the spring. Its safe to say thats pretty good considering and would require more inital spring pressure to get more overall pressure out of the system. OR a 4 port controller OR two 3 port controllers on your current springs in the gates.

 

my friend is running a front mounted gtx42r with dual 44mm Tial wastegates with 11lb springs in it with a hondata solenoid and s300. When he went to go tune, they cant get any less than 30lbs of boost...anyone know what the issue can be?

 

That sounds completely unrelated to this old thread. Start a new thread and list all the details of the setup.