Help ASAP - cannot get velocity turbo / header assembly to mount (lots of pics)

juissed

Registered
Hey guys- during final assembly and testing of my stage 1 velocity kit, I ran into an issue while verifying the wastegate spring pressure.

In testing, the wastegate would not open until 14psi from an air source. During troubleshooting, I found that the wastegate actuator rod was rubbing against a banjo bolt on the block. I pulled the turbo assembly off and tested on my bench- opens around 9psi or so now. Seems about right for this setup.


When reinstalling the unit, I cannot get the damn thing to snug up against the block without it hitting this banjo bolt or an oil line. (This line feeds from the front of the block to the left side.. not sure what its purpose is honestly)

I'm using ARP header studs & cometic crush gaskets in the head. The gaskets don't look too crushed to me, but I'm inexperienced with this type..

If I tighten the top bolts only and snug the bottoms, I can get the turbo unit somewhat aligned, but the actuator rod will still contact this banjo bolt head not allow for proper movement. It also throws off the chargepipe alignment making it a real ***** to get the silicone coupler & clamp installed.

Here are some pics highlighting the issue:


This is the chargepipe alignment which tells me the bottom of the turbo should be closer to the base:

HLKa3CQ.jpg

SsJHV4C.jpg


Here is a pic from the previous owner's install of the turbo & header assembly:

EDFlZFu.jpg


His looks to be installed correctly..

Here are two shots showing the actuator rod rubbing on the banjo bolt and the oil line. The second show shows how the actuator bracket was previously clearanced:
X0w5HeQ.png

Xu1ZL4H.png



Here is a shot of the head with the cometic gaskets:
cmSd9eT.jpg


Here is the turbo / header assembly:
HHNfO17.jpg

AY9EeN8.jpg


Here is the head showing the two problem areas.. the oil line and the banjo bolt:
XuiDpkx.jpg



Anyone ran into this issue before? I attempted to slide the turbo forward by removing it from the header flange, but the bolt holes are not elongated-- it does not allow for any adjustment.

What is the oil line that goes from the front of the block to the left side used for? Can it be removed?

What is the banjo bolt line for? Can it be removed?

Should I double up on the header gaskets or switch to a different brand / type?



I received the instructions from Jason @ RPM for this kit-- but it looks nothing like the examples shown and it doesn't mention anything about touching oil lines or banjo fittings on the left side of the bike.
 
I have a Velocity kit on my Gen1,it looks NOTHING like what you have,absolutely completely 100% different. Bolted up no issues,you sure its from Jason?
 
Yeah apparently there are a couple versions. I bought the silicone charge tube 90* that curves through the frame and its a fit.
 
That's the next thing to try- should I use another set of cometics or somethig different ?

Mps is about 10 min from me, but they only stock the cometics..
 
That's the next thing to try- should I use another set of cometics or somethig different ?

Mps is about 10 min from me, but they only stock the cometics..

Juissed: your turbo is "clocked" incorrectly. With the header/turbo combo installed on the motor, you can loosen the bolts that hold the compressor housing and rotate that housing to get the clearance you need. This is common when doing turbo installs. Once you clock that housing correctly, your charge pipe will be more parallel to the frame, as it should. The actuator rod angle will also change, and that adjustment would need to be checked also . . .:laugh:
 
  • Like
Reactions: Zee
Clocking was the answer to getting everything aligned. (Along with adding a set of OE header gaskets on top of the Cometics) Fits great now.


The next problem though is that the wastegate is still taking way too much pressure to open. It's well over 10# Looks to be 12-14#

The previous owner only ever ran 8, and said it's the original internal gate from Velocity. Any tips? I've verified that it's no longer rubbing / binding.. Do these things read high when it's not running? I'm nervous to button it up and get it on the dyno just to have it overboost to 14psi and pop the motor.


Anyone have a source with replacement wastegate actuators in stock? I haven't had the best of luck receiving timely or accurate orders from RPM...
 
Clocking was the answer to getting everything aligned. (Along with adding a set of OE header gaskets on top of the Cometics) Fits great now.


The next problem though is that the wastegate is still taking way too much pressure to open. It's well over 10# Looks to be 12-14#

The previous owner only ever ran 8, and said it's the original internal gate from Velocity. Any tips? I've verified that it's no longer rubbing / binding.. Do these things read high when it's not running? I'm nervous to button it up and get it on the dyno just to have it overboost to 14psi and pop the motor.


Anyone have a source with replacement wastegate actuators in stock? I haven't had the best of luck receiving timely or accurate orders from RPM...

Did you adjust the actuator rod properly? Clocking the turbo changed the angle of that rod, and it needs to be set. What you are going through now is the difference between taking it a shop that knows what they are doing and doing it yourself. That is - many times - also the difference between being happy with your build and blowing it up. Your entire build should be checked before you even think about the dyno . . .
 
Just a word to the wise, if 8psi is your target, I'd set it to a little lower then 8. Those aren't exactly the best turbos. Once you get some back pressure on the exhaust side it will bump your boost higher.
 
Just a word to the wise, if 8psi is your target, I'd set it to a little lower then 8. Those aren't exactly the best turbos. Once you get some back pressure on the exhaust side it will bump your boost higher.

A full exhaust system on an internally-gated turbo will have less tendency to spike . . . using a dump pipe will give that same type of setup a better chance of spiking and going above wherever the actuator might be set, especially in the higher rpms. Porting these turbos is a good idea . . .:laugh:
 
A full exhaust system on an internally-gated turbo will have less tendency to spike . . . using a dump pipe will give that same type of setup a better chance of spiking and going above wherever the actuator might be set, especially in the higher rpms. Porting these turbos is a good idea . . .:laugh:

Didn't notice it was a full exhaust, but your right as far as spiking. I was talking about boost creep in the higher rpms due to insignificant waste gate porting, and flapper diameter.
 
Didn't notice it was a full exhaust, but your right as far as spiking. I was talking about boost creep in the higher rpms due to insignificant waste gate porting, and flapper diameter.

You are absolutely correct, which is why the Mitsu Super 16s and 20s coming in the newer Hahn kits are ported; however, they do not change the actual diameter of the flapper. Hahn turbos do better than they did ten years ago, however they have still not alleviated the problem entirely . . .
 
You are absolutely correct, which is why the Mitsu Super 16s and 20s coming in the newer Hahn kits are ported; however, they do not change the actual diameter of the flapper. Hahn turbos do better than they did ten years ago, however they have still not alleviated the problem entirely . . .

Yep, that's why back in the mitsu turbo haydays I wouldn't even install one without hogging out the port, and installing a 32mm flapper. (Might of been 34, it's been awhile.)
 
Back
Top