Solution to boost drop at high rpms? Spring the wastegate actuator?

[MusPuppis]

Lets face it, if we had the money we would all own a new Porsche turbo.

 

I dunno.. I'm sure some folks see it that way, but I'm not one them. If I had 80k to spend on a car, bet on my Z getting the Rb26DETT and one way or another becoming AWD with one hell of a motor and chasis buildup to boot.

 

Z's have always captivated me from the first moment I saw a beat up, peice of utter and complete **** 280 sitting in a parking lot rotting away. I was 15, and from that day on, Ive been hooked.

 

I am one of the penny pinchers though - lol. And man, I am one broke son of a gun. But the low cost of the Z is never what appealed to (its a nice thing though imo..) its the look and feel of the car.

 

I agree completely with the aftermarket though. Z folks are by and large a group of DIYers.

[Thumper]

But I guess welding a turnbuckle inline with the stock WGA arm would achieve much the same result.

 

From what I understand just making the wga adjustable wouldn't fix the boost falling off at high rpms. What you need is a stronger actuator so that I can hold the wastegate shut at high rpms. I put a mbc on my friends 04' and it hits 19psi and then slowly drops to 12-13psi by redline. With the aftermarket wga it should do 20psi then drop to 16-17psi.

[Guest bastaad525]

well there's other things involved as well. Exhaust restriction is one big part of why boost falls off so bad on the SRT even with an upgraded WGA. The pressure builds up and up and just forces the WGA open.

 

On the Z however, seems a lot of guys don't have the problem of boost falling off with rpm. When L28ET was stock it held 7psi all the way up, and when I added an MBC it stayed at 10psi all the way up. It was only after I installed the I/C that I noticed boost started falling off with RPM, so I assumed my I/C was causing pressure drop as flow went up.

 

 

I know I just got this WGA on my SRT-4 but I think I'm gonna take it back off. Yeah it makes noticeable extra power over the stocker especially after 4500rpm it just keeps pulling which it did't do as well before. BUT it boosts TOO quickly and easily now, talking full boost at 1/3 throttle, which this car does NOT like. It surges and shudders and makes this horrible fluttering sound, which some poeple say is compressor surge, some say is the BOV fluttering (computer controlled, computer doesn't expect boost at 1/3 throttle), some say it's the wastegate flap fluttering.

 

I dunno but it feels like it's bad for the car. Some guys at the SRT forums (like 80% of people over there have an upgraded WGA) will say "you need to relearn to drive you car and drive aroun dit" and that just sounds utter BS to me. With the WGA on the car has basically two ways to drive now, moderate cruise or WOT. I don't think that's worth an extra 20hp, I don't live at a race track.

[Thumper]

well there's other things involved as well. Exhaust restriction is one big part of why boost falls off so bad on the SRT even with an upgraded WGA. The pressure builds up and up and just forces the WGA open./QUOTE]

 

This is why an upgraded wga helps. It has a stiffer spring in it so that it won't be pushed open at high rpms. Remember that the only thing that controls what boost the actuator opens at is how strong the spring is. How much boost in the diagham it takes to overcome the spring. Well also the size of the actuator, surface area etc... But if you have a stock wga and an aftermarket wga then the biggest difference will be the spring pressure. On the srt-4 though there is only so much you can do. The turbo can only put out 18psi at redline no matter what you do. But if you have a stiff enough wastegate actuator you can go to 18psi and then keep it there without any boost drop off.

[Guest fatherkares]

basically the problem ive run into, after becoming a fan of these car's and buying one myself, is that the wastegate in my 1981 280zx turbo i think may be busted or just not working proberly.

 

Issue is, " when i really step on the peddle to take off, a clicking sound will reoccur many times aslong as my foot will stay accelerator". i would say, right when i step on it, all u will hear is : click, click, click, click, click.

 

so any suggestions on where i could find a new wastegate and what type, or what could be done if you know what the problem might be

[Thumper]

Click, click, click is no good. Read up on the safety pop off valve. It could be that. Or something totally different. 99.9% sure someone has had your problem before so you should be able to find it.

[rvandivort]

Where do You get different springs? Supplier on line.