new 5" downpipe, ported wastegate, boost spike. grrr. angry

[413turbo]

i got a used 5" to 3" downpie. got it installed. it is going to pypes dual exhuast system with no cat. so it was working, but had a major boost spike issue and produced (in my mind) alot of underhood heat. so i go and get it and my exhaust housing coated, it didn't seem to make a bit of difference. i port the wastegate hole to within 1/8" of the puck. just went for a test drive, it is still spiking and creeping. it did go from a 5-6psi spike down to a 3-4 psi spike after porting.
What Now???

i am just running a te60 turbo and didn't plan to move up much higher than that. do i need a .85 housing? more porting? the only thing that i can think of is it is bottlenecking the exhuast, hence to fast flow and spike. please tell me i am wrong and that this can work... with my combo.

 

[89drivin87]

it could be the way you have your lines ran to your wastegate.i know when i first got my buick it had a 3 psi spike because of the lines.I got all the excess T's out.Basicly turbo to boost contoller into wastegate.or turbo and wastegate on one line running into the controller as a bleeder.which ever way works.they both work for me.my turbo spooled up faster with the controller as a bleeder. hope this helps

 

[Quick6'n'-K.C.]

Loosen the wastegate rod, stretch the spring on the rjc.

What boost level are you running?

How much 7/32 hose do you have, get some smaller diameter hose and make them as short as possible.


Spike can be controlled with setting it up correctly, what boost controller are you running rjc?
How long are your hoses.

The downpipe isnt going to cause more under hood heat

BW

 

[413turbo]

well to me it just feels hotter, but after a long drive- i think it'll be ok.

i'm running the rjc valve, was set to 17-18 before. i tried turning the rod out 1 more turn, didn't help, i'm going to loosen it 1 more later.

i just got on it 3 times - spikes to 20, drops to 15, creeps back up 17-18.
no kr, 751 o2 and 762 o2. on 20% e85( 1:4 w/ 93)

 

[413turbo]

loosened the rod 1 more turn, now it just slips on. same thing.

i'm running from the turbo , straight into rjc valve, then into wastgate. i don't think i could squeeze smaller line onto it.

 

[WSLN 6]

Does the RJC valve have a bleed hole on the exit side?

 

[413turbo]

bleed hole - yes

tried again - tightened the rod back up to 1/8", 2 turns to the rjc valve,
WOW!!! spike to 24-25, then back to 18-19, no kr, and now it is getting to be fun to drive.

it was a pain getting the rjc setup last time, but i got it done, didn't have to port the hole, worked great. i think i could only remove another 1/16th from the hole now. maybe i need a hd actuator, i don't know- but i wish i did.

 

[413turbo]

went thru all the old post on spike.
decided to start from scratch again.
took the rjc valve apart cleaned it, and put it on 2 turns.
made the wastgate rod to where it is allmost loose on the puck.
first test drive went to 15lbs.
turned the rjc in 3 turns, went to 18, then dropped to 15, then creep up to 18.
not perfect, but my hope is getting restored. i think i'' loosen the rod another 1/2 turn.

 

[ijames]

No suggestions on the creep, but a bigger dp does put more heat into the engine compartment. Bigger the diameter the greater the surface area and thus more heat transferred. Plus, a th style pipe is effectively 6-12 inches longer than the stock elbow, so even more surface area. I was really surprised how much hotter everything got when I went from a 2.5" stock style with stock elbow, to a 3" thdp.

Did you see any temperature difference after coating your exhaust? Not sure if your "not a bit of difference" was about temp or boost creep .

 

[413turbo]

that was my thinking on the heat, just more surface area = heating more air. at first i didn't think the coating did much to reduce the tempature, maybe it just needed to go thru a few heat cycles, because now it does seem a little bit cooler. i'm going to take some temp reading at 1" from the pipe and compare them to the un-coated header flange, if my probe will go that high. it was coated with turbo-x from techline.

 

[turbo6man]

5" downpipe

I have the RJC 5" downpipe to the first 90 then I made the rest out of mild steel (see pic). I thought it put alot of heat so I bought some header wrap from summit and put it on. It did help, but it did something much better, Before wrapping it, the 5" downpipe made a drone or resonation of exhaust noise in the cab at cruising speeds (like the old flowmaster mufflers used to do). After wrapping the 5" downpipe the resonation was totally gone!

 

[413turbo]

still not working.
i set the rod up to where there was no spike or creep, went right to 14lbs. steady. then i put the rjc back on, spike returns.

i then turn the rod all the way in, and remove the rjc again. wow, i'm running a full 16lbs. (should be way more).

i don't think my puck is catching the hole. i don't see any vacuum problems that are visible, doesn't seem to have an exhaust leak.

anything else i need to be looking at?

 

[GNVYUS 1]

Does the RJC have the small hole on the controller to help venting?

Running the wastegate rod that loose is going to hurt spool up, I'd try this.

Put the wastegate rod back on and go out boosting, loosen the RJC set screw until it's not adding any boost over your rod. Then readjust it so it's adding 1psi of boost over your current wastegate rod setting.

From here on out, just use the rod, you should notice a faster low end spool and a decrease in spiking.

Smoothing and rounding the edges in the turbo housing wastegate hole is as important as the size of it.

 

[413turbo]

yeah it has a vent hole,
but re-read-
with just the wastgate going to the comp. housing- and the rod as short as it goes- only 16lbs.

i know the puck covers the hole, but it either isn't sealing, or i have a pre-turbo exhuast leak, i'm guessing.

i checked the pcv today, how long to drive before the hole will be lined with carbon, so i can see if it is sealing?

 

[413turbo]

and to make matters worse, i was just sitting in front of the car, tears rolling down my face. my girl walks out and asks what's wrong. i tell her i just can't get more than 16lbs of boost. she says, that's good.
she says it was getting to where it hurt her stomach when i'd get on it.

 

[413turbo]

and if the puck covers the hole, but isn't sealing, what's the fix for that?

 

[GNVYUS 1]

There are two wastegate actuators for us, a 12psi ( or 14psi, dammit ) and an 18psi. Somehow you're in between so I don't know what's up there.

But if you have the HD actuator it's not going to get really low anyways so try my suggestion and go from there.

 

[413turbo]

ahhh, i'm following you. i'm pretty sure i did that today also, but will give it another shot tomorrow. i think that was working, but i could only get it up to 19lbs doing that.

 

[Turbo6Smackdown]

Have you tried just using the normal wastegate solenoid, and taking the boost controller off?

 

[413turbo]

yep, here's where i'm at now:
no exhaust leaks can be found,
did the boost leak test, everthing came out good but the stem of the egr valve is leaking a little.
took the vacuum off the actuator and it ran up to 20lbs. -but i'm scared of damage, so i didn't try to hold it there.
cut the rod, and went all in- spiked to 19lbs. then settled back to 16lbs.
actuator is holding vacuum.

and i'm ready to scream.