My Bodgy Wastegate actuator mod.

[Cubes]

I had a thought tonight which is dangerous.

I ripped out the wastegate actuator & drilled a couple of 9mm holes next to the origional mounting holes to allow the wastegate actuator to be pulled back and tightened up if you like.

What I'm hoping to do is restrict the full open movement so it helps prevent boost drop in the higher RPM's.

I was able to get in a few fiddles before it went dark tonight.

I'm not using a boost controller.

First tweak showed around 14psi being held up to around 5500rpm where boost dropped by 1psi.

Second tweak bumped boost up to around 16-17psi where up around 5000rpm I hit the fuel cut & heard a little bit of pinging due to boost rising slightly more. Hence the wastegate wasn't able to open enough to control boost.

I tweaked it back a little and moved it too much.

I tweaked again and got it up to around 14.5psi with boost only dropping 1psi over 5500rpm.

Previously it wouldn't matter where I set boost to with a bleeder or EBC in manual mode, it would always drop back to 12-12.5psi over 5500rpm.

Tweak a little more and bring the top end boost up to around 15-16psi.

Its a little bodgy but hey.. its free.

Should be interesting to see if it pans out tomorrow.

Be carefull playing with this bodgy mod people as I've soon got another motor to play with so i'm not to fussed about damaging this sucker.

I'm trying to get it to hold boost for the next dyno day.

Then compare it to the new motor.

[RBVS]

interesting, that boost drop is a common problem.

good effort

[Cubes]

It appears with a bleeder it will only hold roughly 1.5-2psi more than the actuator is rated at.

With a EBC in Auto mode with fuzzy logic it will hold what ever boost thrown at it, my Blitz SBC-iD had no problems holding 15-16psi up top.

[Bl4cK32]

So i guess its all out war on the rb20 then Joel

People can post here ideas they always wanted to try on the rb20, but were too scared incase they blew it up

[Cubes]

Looks like it.. Getting ready for the dyno day.

I fiddled with the actuator on the way home from work this afternoon with excellent results.

It took 2 tweaks to get it holding boost up top like I wanted it to.

The final tweak came up on to 15psi pretty hard then in third & fourth slowly creeps to 16psi.

I've tweaked the bleeder a little to bring it straight up on to 16psi and now it holds perfectly flat from 3500rpm (16psi) to 7000rpm. No point reving to 7500rpm.

Defiantely screams up top now. Huge difference in second as previously it would start to die off after 5500rpm and feel like it was just reving, now you can hear the turbo really pshhhhhing while you feel that rb20 top end scream.

[Dayna]

hey, i also had an in line restrictor boost control, and even bleed control. but i thought the cheapest and best option was that same idea, i drilled a couple of holes and routed in through to the original holes, i am happier with the result, pity i had wasted money on the other boost mods, as this ones cheaper! like no cost!, also i have been playing around with the use of springs onto the wastgate lever, simple way of making the wastgate change its characteristics, just use a heavier spring for more boost.

the only thing i noticed is that if reving 3rd,4th,or 5th when lower in the rev range, the boost will go higher than your optimum gear reving up, but i guess you should always be in the best gear of acceleration if you want to accelerate, even in town driving. just alot more foot control need to be used.

I personally would love an electronicly controlled system, were boost was held perfectly at pre selected levels. but at the price of nudda for the above setup i keeping my money for better value mods.

ps i keep my boost max at 14 but mostly around 12, reliable factor.

Dayna

[Guest RedLineGTR]

coolies with have a muck around with it on the weekend

[Cubes]

Dayna,

EBC's arn't all they are cracked up to be. Well mine wasn't as good as I expected it to be. To be honest it was a little dumb and required fiddling with every now and again.

Even when the ebc was in auto mode (dial in the psi you want and it does the rest) & driving up a hill in say fourth gear with lowish rev's boost will climb and spike to 17-18psi where the safety ebc thing would dump the wastegate open. + in auto mode the boost wouldn't hit as hard.

When the EBC was in manual mode which works on a percentage of maximum boost it wouldn't spike up hills etc but it also wouldn't hold boost up top. In manual mode boost would hit nice and hard.

I was going to fiddle with the heavier spring on the welded wastegate but this seems to do the job nicely.

Up hills etc mine doesn't spike high if anything it tends to come up to 1psi under what it runs when at 7000rpm.

RedlineGTR,

Have you tried a RB20DET turbo actuator. They hold 10-11psi standard.

[Guest RedLineGTR]

RedlineGTR,

Have you tried a RB20DET turbo actuator. They hold 10-11psi standard.  

       

nope havent tried it...i'll see what i can dig up

[JAS-25T]

guys

i have also looked into this, although i havent tried it, if you think about it, if you in effect shorten the amount of travel on the actuator the effect will be somewhat like an oxy torch where you have hot gasses comming out of a small(er than usual) hole, in this case the wastegate, and burning the wastegate, which in time would become burn on the edge in the same way metal is cut using an oxy cutting flame.

so be carefull...

but like i said this is all only in theroy, it may be different when put to practice, as most things are

[Cubes]

I see your logic however I can't see it being a problem as think what happens when an EBC forces the wastegate to barely be open in order to hold boost high in the rev range.

[JAS-25T]

yes, but this is not all the time only in the high rev range,

where as yours would never be able to open to the full extent.

[SlowGTS-t]

guys

i have also looked into this, although i havent tried it, if you think about it, if you in effect shorten the amount of travel on the actuator the effect will be somewhat like an oxy torch where you have hot gasses comming out of a small(er than usual) hole, in this case the wastegate, and burning the wastegate, which in time would become burn on the edge in the same way metal is cut using an oxy cutting flame.

so be carefull...

but like i said this is all only in theroy, it may be different when put to practice, as most things are

No it wont burn the little flap. It would melt the exhaust housing too if it was that hot. Even with the actuator in its standard position, the wastegate never really "fully" opens.

Bending the actuator arm is another way of doing it. Just dont break the arm.

[JimX]

Have you thought about cutting the end off totally, tapping a thread onto the remaining part, and somehow making a "socket" threaded rod with a mounting hole in it? This would effectively turn it into an adjustable actuator the same as the HKS ones.

[Black33]

Have you thought about cutting the end off totally, tapping a thread onto the remaining part, and somehow making a "socket" threaded rod with a mounting hole in it? This would effectively turn it into an adjustable actuator the same as the HKS ones.

I've thought of this in the past and think it would be pretty simple to do - if i could be stuffed

[Guest Robo's]

Hmmm, interesting, i might have to try something too!!

I can watch my boost drop from 12psi to 10psi as revs rise, damn i hate that

[Jay95R33]

Hmmm, interesting, i might have to try something too!!

I can watch my boost drop from 12psi to 10psi as revs rise, damn i hate that

Since my last dyno run, and I watch it drop from 12psi to 9.5psi as the revs got up high, I've been pondering the same thing.

Any idea what an HKS adjustable actuator costs??

I'm pretty sure it would be the spring tension, it just can't hold the flap closed as exhaust gases increase and speed up

I'd be keen to hear from someone that has done the 'R32 actuator on a R33 turbo' mod

J

[Black33]

wouldn't the boost drop jhust be due to the stock turbo not being able to flow enough at high revs?

[JimX]

Any idea what an HKS adjustable actuator costs??

New I think around $150-200. Mine cost $75 second hand. If you see one for under $100, I say grab it. Definitely worth the bucks if you're dropping boost.

[Jay95R33]

wouldn't the boost drop jhust be due to the stock turbo not being able to flow enough at high revs?

That could also be a factory in it too But I think at the relativly low boost, I'd say the actuator is the main reason.

Thanks JimX - that's a good price and I'll be keeping an eye out for one.

J