T61 Bolt on Turbo by Cx Racing

[CBatstone]

I purchased this turbo last night and today I scoured all 43 pages of this thread and took notes to summarize the issues I’ll encounter. I had a few questions after reviewing all of the great material here in this thread.

1.
One question I don’t feel was answered completely has to do with the turbo elbow, the stock one being insufficient. I’ve found some downpipes with elbows with split waste gate ports and I’ve found simple supposedly larger elbows. What is necessary here to avoid the turbulence that could cause waste gate chatter or compressor surge? Will a larger elbow be enough, because it seems like the same problem would exist with the stock elbow as an aftermarket one since the waste gate port is still dumping into the same area?

2.
Someone had noted that the Bolt size for the downpipe was incorrect (was 10x1.25mm, should be 12x1.25mm)

Did you just center it and torque it down? What was the fix here? It reads as if the bolts were smaller on the turbo than the holes on your average MK3 downpipes.

 

[Poodles]

Stock elbow the wastegate basicly empties into a WALL. It's a terrible design, and with a divided housing like on this turbo I don't know how it could possibly flow enough to prevent overboosting. Most aftermarket elbows will be fine as they don't have that wall.

 

[paradox616]

I purchased this turbo last night and today I scoured all 43 pages of this thread and took notes to summarize the issues I’ll encounter. I had a few questions after reviewing all of the great material here in this thread.

1.
One question I don’t feel was answered completely has to do with the turbo elbow, the stock one being insufficient. I’ve found some downpipes with elbows with split waste gate ports and I’ve found simple supposedly larger elbows. What is necessary here to avoid the turbulence that could cause waste gate chatter or compressor surge? Will a larger elbow be enough, because it seems like the same problem would exist with the stock elbow as an aftermarket one since the waste gate port is still dumping into the same area?

2.
Someone had noted that the Bolt size for the downpipe was incorrect (was 10x1.25mm, should be 12x1.25mm)

Did you just center it and torque it down? What was the fix here? It reads as if the bolts were smaller on the turbo than the holes on your average MK3 downpipes.

1) I had my exhaust from turbo back made on the car by a few guys i know that run a exhaust shop, divorced downpipe until the floor pan pretty much. as poodles said, stock is a horrible design, i got the flange lazer cut and a 3" pipe all the way to the end tailpipe.

2) don't use the bolts that come with it, they are weak and most likely will snap when you go to undo them after running for a while, use some high tensile metric studs and nuts, Correct about centering, i lined it up the flange and use a jack to support the dump pipe then tightened the bolts, the casting isnt too bad on the exhaust housing.

to follow up on the wastegate flapper arm sliding issues, here are some close up pictures, compare the flapper position in each picture and the circled section

Here is a picture of my setup, apart from my braided lines it tucks away nicely and could almost pass for stock.

 

[CBatstone]

That cutout you circled seems a bit oddly shaped, I'm not sure what would have created that. Looks like a rough torch cut out, but I don't have others to compare it to at the moment. The e-bay photo has the same shape cut-out visible in the stock photos. Is the sharp piece you circled able to rotate down (in the direction of the shaft that runs through the hot-side housing) and get stuck on the round piece below it? Allowing it to not fully close? It is hard to tell where the shaft ends. What are you considering as a fix? Maybe an extra spacer or a file to smooth the contact of the pieces?

---

Does anyone know if a typical after-market down pipe elbow would work well enough or do you need a fully divorced waste gate chamber in a down pipe for this size of turbo with an integral waste gate?

http://cgi.ebay.com/ebaymotors/Turb...r_Truck_Parts_Accessories&hash=item3a504b9bbe

vs.

http://cgi.ebay.com/ebaymotors/86-9...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

 

[Poodles]

Either of those will work fine, but the second one will have to have the divider removed more than likely.

 

[CBatstone]

Right-on yeah I see what you mean. Is there any substantial benefit from going with the divorced waste gate pipe over the simple larger elbow? I already have a 3" down pipe and it would save me 200$. But if its really worth it...

 

[IwantMKIII]

^BIC's (i believe) divorced DP added about 30HP surprisingly. There are dyno graphs around here of the before and after standard 3" vs. 3" with divorced setup.

 

[paradox616]

i defiantly noticed a benefit going to DDP, after all it avoids turbulence in the dump pipe,

I'll get a micrometer and measure the wastegate port while its off as well.

its not oddly shaped, the flapper is allowed movement! my theory is the flapper is currently hitting the upper edge and allowing gasses to be leaked before boost, when i pull it i will confirm. these pics are old.

The flapper in the first photo is adjusted low where as the flapper in the 2nd picture is adjusted high. i have had a case where the flapper has become jammed open on the housing.

i was thinking a stopper welded onto the shaft at each side of the housing might prevent the shaft moving. I'm sure IJ would know the best way to eliminate shaft movement.

 

[IwantMKIII]

^have you contacted cxracing about this issue?

 

[IJ.]

i defiantly noticed a benefit going to DDP, after all it avoids turbulence in the dump pipe,

I'll get a micrometer and measure the wastegate port while its off as well.

its not oddly shaped, the flapper is allowed movement! my theory is the flapper is currently hitting the upper edge and allowing gasses to be leaked before boost, when i pull it i will confirm. these pics are old.

The flapper in the first photo is adjusted low where as the flapper in the 2nd picture is adjusted high. i have had a case where the flapper has become jammed open on the housing.

i was thinking a stopper welded onto the shaft at each side of the housing might prevent the shaft moving. I'm sure IJ would know the best way to eliminate shaft movement.

I could have a look when you get it off if you like?

 

[paradox616]

I could have a look when you get it off if you like?

Cheers I'll let you know once i've removed it.

^have you contacted cxracing about this issue?

Yes I have, I got no response from them as of yet (sent a email about a week ago and sent another email today with pictures posted here)
I doubt they will fix the issue..

---------- Post added at 04:24 PM ---------- Previous post was at 04:20 PM ----------

Got a response from CX Racing saying they are looking into the design fault

 

[paradox616]

Got bored and pulled the turbo tonight, the flapper was sitting at the bottom like in the first picture above

tested the actuator, starts opening @ 6psi and is open by 8psi... added a bit more preload so it starts opening @ 8psi and is fully open by 10psi

I took a video uploading soon , there is a outer shell casing the flapper shaft... i think its supposed to be pressed in place. if i welded it to the housing it would effectively stop play all together! not sure if it was like this when i got the turbo or if it happened.

IJ, i'll pm you.

 

[paradox616]

Wastegate flapper is fixed now

Went over to IJ's house and we put a grub screw in there to hold it in place.

I measured the wastegate and the port is 28mm in diameter, my stock ct26 port is 24mm, I'll put it all back together and see if there is any improvement.

 

[IJ.]

Was good meeting you and the Mrs G!

 

[paradox616]

Was good meeting you and the Mrs G!

was good to meet you as well, while we talked cars apparently my missus was studying the calendar in your garage She was trying to work out of they were real or fake.

 

[IJ.]

was good to meet you as well, while we talked cars apparently my missus was studying the calendar in your garage She was trying to work out of they were real or fake.

LMAO can't say as I've paid that much attention to it to be truthful!

One of my suppliers gave it to me and it replaced the one that was up there as it was full of bushpigs

 

[black89t]

WOW. being able to drive over to IJ's house for a hand is so cool.


we're all so jealous of you paradox. :biglaugh:

 

[IJ.]

WOW. being able to drive over to IJ's house for a hand is so cool.


we're all so jealous of you paradox. :biglaugh:

It's actually quite rare for this to happen as I'm not active in the Aussie Supra community, was happy to help Paradox out he's a nice guy!

 

[wiseco7mgt]

I'm coming for a drive one day Ian, just to meet you and see your beast in the flesh. (By beast i mean your car not your....well you know.)lol

 

[IJ.]

I'm coming for a drive one day Ian, just to meet you and see your beast in the flesh. (By beast i mean your car not your....well you know.)lol

LOL Pete can't be sure after reading your Sig
I should be in the new place before years end so I'll have room for guests, you're always welcome to come visit.