turbo keeps on spiking, please help?!!!!

[soyee7]

I hope you guys will be able to help me with this. I put my car on the dyno tonight and we tried to run it but my turbo kept on creeping past19psi, i have the evo316g with the stock wastgate. I tried tuning the profec b to keep the boost down but it just kept on creeping from 19-24. so we then unhooked the profec and decided to hook up the hose on the waste gate nipple to the intake charge which should allow it to boost at stock psi but it still creeped. What do you guys think this could be, i think it might be a faulty waste gate that sticks open. If it is im gonna just buy a tial and put it on this weekend. please let me get any info that you can.

On the spike at 4500 rpm my UNTUNED eclipse ran a 279WHP.

[kjewer1]

Are you talking about boost creep, or boost spike? I'm inclined to think you mean creep. Creep is when the boost will go to set boost, but at some point it will start to rise on its own all the way to redline. For example, boost will rise to set boost of 16 psi at 3500 rpm, but from 5500 to redline it keeps rising to 19 psi. Spike is when boost overshoots your set boost point then settles back down for the rest of the pull. For example, you floor it, boost shoots to 19 psi, then settles back down to set boost of 16 psi till redline.

Spike is a function of the wastegates ability to react quickly. And if it was a sticking WG, it would be one sticking closed, not open. Try using strong reinforced hoses. I use 1/4" fuel injection rated fuel line. Dont use small crappy lines. It will also help if you take the boost source for the PRofecs solenoid box from a lower intercooler pipe, not the manifold or BOV line. I never got any spike with the profec B, and I have run almost every turbo imaginable on my car, from t25s and 16gs, to 60-1 t3/t4 and hybrid 56 trims. The box runs off the lower intercooler pipe, and the head unit gets the signal from the manifold.

If it is creep, the external WG is absolutely the best option out there.

[soyee7]

yeah, sorry about clarifying that. I am trying to describle boost creep, my boost wont stop rising. if i didnt let off the gass it would probably go past 20 psi easily. so you think an external waistgate is the best option, which would you recomend, and whats thebest price youv seen.

[JoeWagon]

Tial. If I'm not mistaken, the smallest one (38mm) will do fine on a 16g. The bigger the wastegate, the lower boost you can run without creep... down to WG spring pressure. You'll need it mounted on your exhaust manifold or o2 housing, which you can buy either with a flange for a tial. The absolute best would be the flange mounted in the middle of the manifold, instead of on only 1 runner, like some of the t3/t4 manifolds have. Kevin has this setup where it vents all 4 runners with a Deltagate i think.

[kjewer1]

I do, and its for sale. With the smallest gate, the 32mm deltagate, I can hold 13 psi to redline on a 20g and 56 trim gt30-40. I now run a tial 38 with a 20 psi spring. The deltagate (13 psi spring) and 2g manifold and dumptube that goes with it are for sale. I think pics are still up on my site, www.posracing.net. PM me if you are interested. Another option is to have slowboy weld a flange onto the number 1 runner of your manifold. Its pretty cheap, less than 100 bucks IIRC. But it comes close to the radiator. Joe G is running a 38mm off the number 1 with a 16g and it works fine. The O2 option is nice, but gets pricey.

[boostedinaz]

I dotn like the WG mounted on the #1 runner becasue it will cause a bit of reversion. I would just drop the turbo and port the WG openign and put a 34 mm flapper on it. i little porting can go a long way. I had creep with my 14B and 3 inch O2 elim. I just removed the divider and it worked great. It was something I wanted to rry becasue if I F'd up the turbo I didnt care.

An external would be nice though becasue no matter what turbo you get it will never creep.

Michael

[kjewer1]

LArger flapper will kick you in your ass when you decide to turn up the boost though. Search tuners with my username for "WG blowing open info" for a thread I started on there a while back. Nevermind its your lucky day:

http://www.dsmtuners.com/forums/show...wing+open+info

Avoid larger internal flappers at all cost. Bottom line = internals do not work very well on anything but stock turbos. Sure, I ran them for years, but it was always a compromise. External WG is one "overkill" mod I recomend very early in the modding process if someone plans to go big anyway, or if they can afford it regardless.