Turbo Buick Forums banner

1 - 13 of 13 Posts

·
Resident Idiot
Joined
·
11,462 Posts
Discussion Starter · #1 ·
Hi gang... what size drill bit do I need to use in order to enlarge the wg hole for use with a Terry Houston DP?? Of course I will be using a drill press... thanks.....

------------------
Email Address: mailto:[email protected][email protected]</A>


Current Combo: Stock Turbo, V4, MSD50's, TH DP, JayJackson 62mm TB, 16position MaxEffort Chip.
12.35 & 108.39 Street Trim.
 

·
Registered
Joined
·
1,110 Posts
That would take one humongous drill press to turn a 1.125" or so bit.
The preferred way to do this would be with an end mill. Failing that, I'd open it up with a die grinder and a straight carbide flute. Cover the puck with some white paint or something, bolt it up, and press it against the turbine housing. Use the resulting mark as your guide and leave 1/8" or so lip on the hole for it to seal.

Good luck!


------------------

Orange Park, FL
various cars, some running
 

·
Resident Idiot
Joined
·
11,462 Posts
Discussion Starter · #4 ·
Forgive my ignorance.. I don't know what an end mill is....

I have access (tomorrow) to a big drill press located at a transmission shop.. It's taller than me and has to be a couple horse..

I bought a 1" drill bit that costs $22. Supposedly can drill through cast..

I am not a machinist by any means.. I was planning on clamping the exhaust housing to the drill press with a few clamps. Then slowly drill the hole out to 1 inch.. Is this not going to work? I don't want to mess up this turbonetics .82 housing for the stock turbo.

Also.. my DP is on the car.. can anyone tell me the normal diameter of say a Precision housing waste gate hole?

Should I be fine only taking it to 1"?? I thought new turbos from the vendors came with like 1.25" for the terry houstons...

thanks again..

------------------
Email Address: mailto:[email protected][email protected]</A>


Current Combo: Stock Turbo, V4, MSD50's, TH DP, JayJackson 62mm TB, 16position MaxEffort Chip.
12.35 & 108.39 Street Trim.
 

·
Registered
Joined
·
6,966 Posts
A one inch drilled hole will work fine with the THDP. What turbo are you running?
 

·
Resident Idiot
Joined
·
11,462 Posts
Discussion Starter · #6 ·
Stock turbo...

I have an .82 housing for the stocker that I wish to use...

------------------
Email Address: mailto:[email protected][email protected]</A>


Current Combo: Stock Turbo, V4, MSD50's, TH DP, JayJackson 62mm TB, 16position MaxEffort Chip.
12.35 & 108.39 Street Trim.
 

·
Registered
Joined
·
1,110 Posts
Originally posted by Orlando_87GN:
Forgive my ignorance.. I don't know what an end mill is....



A end mill looks like a drill bit; it removes material with the side of the bit though. Typically, you'd clamp the housing to the mill table and rotate it, letting the end mill carve out your wastegate hole.


I have access (tomorrow) to a big drill press located at a transmission shop.. It's taller than me and has to be a couple horse..

I bought a 1" drill bit that costs $22. Supposedly can drill through cast..

I am not a machinist by any means.. I was planning on clamping the exhaust housing to the drill press with a few clamps. Then slowly drill the hole out to 1 inch.. Is this not going to work? I don't want to mess up this turbonetics .82 housing for the stock turbo.

Also.. my DP is on the car.. can anyone tell me the normal diameter of say a Precision housing waste gate hole?

Should I be fine only taking it to 1"?? I thought new turbos from the vendors came with like 1.25" for the terry houstons...

thanks again..

I think it will work. Just go slow and use lubricating oil to be safe, although cast iron can usually be drilled dry. This sounds dirty, doesn't it?


Good luck!



------------------

Orange Park, FL
various cars, some running
 

·
Member
Joined
·
140 Posts
Hello Mike.

If you are certain that your puck and wastegate holes are centered reasonably close, than I would agree that drilling it out would be fine. On the other hand if the two centers are questionable, than I would recommend that you mark your puck outline on the housing and consult with a machine shop about using the aforementioned end-mill to enlarge the hole. Reason being that your existing hole will act as a pilot hole which would be difficult if not impossible to drill in an offset manner. BTW, my friends THDP puck measured out at just under 1-3/8", which would give you 3/8" total to play with(3/16" landing around the edges). In the end though, a 1" hole seems conservative with the puck of the THDP, so you should be okay.


[This message has been edited by KENNE-BILL (edited December 14, 2000).]
 

·
Resident Idiot
Joined
·
11,462 Posts
Discussion Starter · #9 ·
In the end though, a 1" hole seems conservative with the puck of the THDP, so you should be okay.
I am glad it seems conservative! This drill bit looks huge. Something tells me it will only be used for one thing.

Thanks for the housing Kenne-Bill.

------------------
Email Address: mailto:[email protected][email protected]</A>


Current Combo: Stock Turbo, V4, MSD50's, TH DP, JayJackson 62mm TB, 16position MaxEffort Chip.
12.35 & 108.39 Street Trim.
 

·
Registered
Joined
·
6,966 Posts
No way a one inch bit is great for drilling out 2X4's and running cable thru them. Also good for drilling thru the firewall to get all the gauge, stereo, extender chip, and other assorted cabling thru. Hey you never know it just may become your most used tool.
Happy drillin'....
 
G

·
We frequently enlarge the turbine bleed port in order to attain better boost control under certain high HP applications.

However, we remove the turbo and bring it to a buddies local machine shop and in 5 minutes a perfectly centered and larger hole of preferenced size is machined into the housing.
Sealing off any area or orifice than can injest any debris is very important, as is making sure the hole is round when completed not out of bounds or beyond the size limit of the wastegate puck. We had one where carless dremeling by an owner resulted in an ugly misalignment between the puck and bleed port and it resulted into an impossibility for him to generate quick spooling, when he was trying to remedy a boost control issue.
Our welder and then a trip back to the machine shop bailed the customer out of this one.



Ron

------------------
Ron's Custom Automotive
Certified NJ Emission Repair Facility
1-800-718-7667
GSCA # 2306 / PR Director
www.ronscustomauto.com
[email protected]
 

·
my bitch is on fire!!
Joined
·
908 Posts

·
Resident Idiot
Joined
·
11,462 Posts
Discussion Starter · #13 ·
Just wanted to let everyone know that we drilled out the hole without a hitch.

I expect to put this .82 on the car very soon and see if it really kills the bottom end.

------------------
Email Address: mailto:[email protected][email protected]</A>


Current Combo: Stock Turbo, V4, MSD50's, TH DP, JayJackson 62mm TB, 16position MaxEffort Chip.
12.35 & 108.39 Street Trim.
 
1 - 13 of 13 Posts
Top