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Front Mount HX55 GTO build.

130K views 455 replies 66 participants last post by  ACCLR8N 
#1 ·
Alright. All of the pictures are probably taking a while to load so ill give a quick explanation. I bought this car for 2 reasons. To
A) have a fast car
B) have something that you dont see every day

When I bought the car I had a lot of ideas for what I wanted to do in the future (procharger, maggie, etc) but really left the turbo idea out of my head for some reason. One day I looked at the details on a turbo kit for the GTO; which led to my intrigue. I found there only to be 2 way people usually turbo their GTO's: APS and STS. So of course I looked into the 2 options, and pretty much was focused on the STS because of its simplicity and easy access. I also looked at the pricing which kind of deterred me (being a college student). So I was kind of stumped as to what to do.

I finally just sat down one day and decided (with the help of my good friend Carl H) that a front mount turbo would be rare, relatively cheap, and would be putting out the same power as any entry level FI GTO. (500-550 whp). Now with the first reason I bought the car expanded, I looked at the rarity factor. Front mount turbo GTO's are few and far between, but I have yet to see a HX55 turbo used in any of these builds. So after doing some research I decided to roll with that idea.

Now the pictures. Ill be posting up pictures throughout the process and explain whats going on. This is by no means a "how to" thread because I want to try to keep the car original, but I will answer any questions asked and will be open to constructive criticism from any offered.

On to the pictures.

This is the heart of the operation. A HX55 for a 12 liter volvo semi truck.


Here are the "super secret" specs from Holset. I had to actually email a guy in the UK to find information on it.

The compressor inducer is - 65mm
The compressor exducer is - 98mm

The turbine inducer is - 86mm
The turbine exducer is - 72mm
The turbine housing critical area is - 19cm2


Now since you cant tell how big the turbo is from the above picture, Here are some more pictures with something to compare it to.



Now the parts ive bought over the past couple of months:
Truck Manifolds

Turbosmart 45mm Wastegate

Greddy Type RS Blow Off Valve

Walbro 255
Just threw it in without taking pictures...but im sure you guys know what it looks like.
650# injectors


Our current plan is to chop the truck manifolds and weld on V bands. The manifolds will be mounted upside down. The passenger piping will go round the front of the engine, and the drivers side will "J" up to the turbo.

The downpipe will be made using oval piping to avoid "massaging" the frame rails.

One of the first steps to getting this thing started was buying the Turbo. Carl and I were driving back from college and he had talked about stopping at a turbo shop in the middle of nowhere. Driving up was sketchy, but after talking with these guys for a good 2 hours we were pretty comfortable with them. So I ended up walking out with the turbo after chatting with them about my build.

The next step was my clutch. Of course the stock clutch (with 50k miles) wouldnt hold the power I wanted to go for. So I found a Spec Stage 3 Clutch from a member off of this forum. The install took 2 days. Yes 2 days. Main problem was the Pilot bearing basically seized in the engine. We had to try 3 different tools to knock it out. Overall if that little snag wouldnt have happened it would have been relatively quick. I also found out my old clutch and flywheel were pretty much spent.



And the new spec stage 3 Plus with a flywheel.
 
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#2 · (Edited)
After that the build was on hold for a bit. College was being College....so we had to take a break. Although I did manage to install a wideband in the wintertime. It was a PLX m300, old school, but it reads AFR's, so im happy.


We managed to test fit the turbo in my apartment complex's parking lot, and it looked pretty good. A little tight, but hey; who doesnt like things a little tight?



I recently was given a 2 bar map sensor, but had to order the wiring for it to be applicable with the GTO



Next thing I got was HP tuners. After months of searching I finally found a used program that was quite affordable.

Recently things started picking up again though. Ive ordered quite a bit. I had ordered a Walbro and we threw it in basically the day I got it.

The next day or so we tried installing my injectors, of which I bought off of a member on here as well. Fitment was a no go. Thicker O rings need to be bought and a fuel rail spacer needs to be made. It was a little frustrating because the guy I bought them off of said they were PnP, but whatever.

On to the most recent endeavor. I needed to take off my oil pan to get it tapped into for a drain line.

A while back I was at the drag strip and we had found a lot of fluid that looked and smelled like coolant on the skid plate and side of the block.

We couldnt figure out where it came from, but after dropping the crossmember we found this:


I just ordered solid motor mounts from revshift for a very reasonable 80 dollars. We have also picked up materials to make solid trans mounts..

Long story short we spent 7 hours driving around to get the oil pan tapped. It eventually got done a BRE motorsports. The weld came out good, and the oil pan gasket wasnt melted.




So as it stands, the car is up in the air waiting on motor mounts. I have stoptech brakes and rotors coming in tomorrow as well. So the whole stopping motion will be addressed while the car is still up in he air.
I will update when I get the motor mounts and brakes in.
 
#5 ·
well see...I havnt really got to planning out flanges and such. Im getting the intercooler to deal with fitment of coldside piping, then looking at the hot side.
 
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#12 · (Edited)
Yeah thats why I chose the HX55...i found it for cheap at this turbo shop, and it was the same price as hx 45s and 35s. Simply for the reason that nobody buys them..haha
 
#9 ·
in for pics... Im planning on the passenger side, but this will be interesting. hope it turns out good for ya.

since you're not committed in any which way, slap the flattest filter you can find on the end of that turbo and figure out how you're going to make it fit, before you weld up the hot side and screw yourself. seems a lot of guys forget the filter and then struggle with it at the end.
 
#10 ·
Yeah ive seen that alot. Were probably going to run a intake tube somewhere, or just make a custom set up. There's nt going to be a lot of space so I might just fit the turbo with the filter before I even put it in for sizing purposes.
 
#11 ·
I was considering twin HX35s myself... mostly due to the prices for used ones. Looking good OP
 
#14 ·
realistically man, its not that much for what youre getting out of it. Im not gonna lie, I found a lot of stuff I bough either on the forum, or on craigslist...haha.
 
#16 · (Edited)
well. so comes the first update. sadly the brakes did not come in today. Howerver we installed the solid motor mounts and a custom solid trans mount along with the oil pan.

Here are the solid motor mounts I bought from revshift. These things looked really god when I got them in. And they shipped them overnight for free after talking to them about my blowm motor mount situation. Great guy. However, when we got ye ole engine mounts in and went to put the solid ones in, we found the hole on the engine mounting bracket wasnt big enough. So we had to make the trip to wal mart to get a 1/2 inch drill bit and drill. after removing the engine mounting brace, we drilled the holes and they fit perfectly. I was a little put out they didnt say I needed to drill holes, but it was n biggie.

Here are the solid engine mounts:


Here are the mount installed:


Now for the all important oil pan. we werent so worried about putting it back on as we were worried about clearance for the feed and drain taps. As you can see from the pictures below, we had really good clearence on both taps. The solid motor mounts really helped space everything out.

Feed:


Drain:


Now for the fun first drive. I was expecting a differance, but man, it was night and day compared to 3 days ago. The blow engine mount really made everything boat like. Now with the solids in, Everything is streamlined. Itll break loose in second again..haha

After dropping my friend (and very helping hand) off at his house, i rolled down the window to say see you tomorrow and was hit with a very distinct smell of oil. We got out and looked around the bottom of the car and saw some dripping going on. I limped it back home and put some paper towels under the car to see how much and frm where the oil is coming from. It seemed to be dripping down the cat so it could possibly just be the feed connector.
Updates again tomorrow.
 
#17 ·
damn, glad to hear you caught it. maybe I missed it up there... how many miles does your car have on it, that the motor mount was blown like that?
 
#18 ·
it has about 54k miles on it. I know I blew it at the track (thanks wheel hop) cause we thought I blew a head gasket because of the liquid on the skid plate. then after we got under it we saw it all came from the blown motor mount.
 
#19 · (Edited)
Update. The leak is coming from the fitting in the feed line. Im just going to put the stock plug in for the time being. Thanks god it wasnt the drain tap or anything like that.....
 
#20 · (Edited)
Another update today.

Got my Stoptech rotors installed. I figured Id need some way of stopping this thing quickly so I decided to do a little upgrading.





These thing work really well. Got them of ebay for a great price.
 
#22 ·
A question to those of you with intercoolers....what size did you go with? I am looking to just fill the lower valence with the intercooler (no chopping the crash bar out). Ive found a 28x8x3.5 with 2.5 inch outlets, but are the 2.5 outlets big enough? f so how did you go about pipe sizing for the cold side?
 
#24 ·
Yea I was thinking 2.5 inch would look kinda wimpy when going to the intake manifold, but I just ordered the intercooler I mentioned in my previous post. I havnt ordered piping yet, because I still want to figure out how to route everything. I thought about doing 2.5 from turbo to intercooler, then 3 from intercooler to manifold, but Ill have to see. Thatll make thing a lot more difficult from and ordering standpoint (cx racing has a lot of kits, but not any with different sized piping diameter).

On a side note I found Some gauges that I like a lot. The company is Depo Racing. Carl has the Defi 60mm gauges in his car and I love them, but since they dont make them anymore I started looking around. These are cheap, accurate, and look good. They change to 7 different colors as well.

-So theyre called Depo Racing
-gauges will be Boost and Oil Pressure
-Sizes will be 60mm
-I will be mounting them in the center of the dash (since they come with stands ill have to make a slide-in design with the removable factory top center piece)
-Wideband will be relocated somewhere..... Ill prob cut a hole that will fit it on the rounded part of the center piece (the front part of the removable plastic part)

 
#25 ·
Those look exactly like the PROSPORT gauges. I have the Fuel and boost gauge. They're okay. After a while you may or may not have problems with them. But the price is still good...

As Doric mentioned earlier, you should move that ECU into the cabin. It will only take a couple of hours at most, and potentially save you lots of time, money and headaches.
On my 04, I was lazy and decided to wrap mine up with heat tape, shield and wrap. I just moved it into the cabin a couple of weeks ago because the plastic connectors started melting lol.

Also, don't be afraid to go with a small diameter cold pipe. They flow more than you know. Just measure I.D. outlet on your turbo and use that same size to run to your IC. It will make is SO much easier on you when you route piping. Then run a 3" back up to your TB. I went with a 3" to 4" expansion for the looiks.

Good work!
 
#30 ·
And this is Carl. Hes helping me alot with the build. HE will also be tuning the car.
 
#27 ·
I think that intercoolers gonna be abit small,
get a 24x12x4" with 3" in/out , if your turbo compressor is 3" out ,you don't want to be going back down to 2 1/2".
 
#29 ·
I mean, id rather the intercooler be used 100 percent rather than have 80% of it being used. Im just filling the lower air dam, and these dimensions SHOULD be perfect....we shall see.
 
#32 ·
Quick update. I wish it was a positive one but eh...not everythings gonna be easy.

Got this today:


Took it to Carls house, did some poor cutting for clearance:


This was on the top of the IC..
after we welded on some L brackets we realized (even though we measured half of the crash bar) the IC was off center. I had been grinding down the bumper for about an hour trying to get the bumper to pop on, but with no luck thus far... After about 2 hours I just packed it in the trunk and called it a day. Ill have to get back to it later.

On a side note, my gauges are supposed to be coming in by Wed now, and I just ordered an injector adapter kit (kit includes thicker O-rings, and fuel rail spacers)
 
#33 ·
is it just me or is that intercooler waaaay thick??
 
#35 ·
eh...its 3.5 inches thick. So yeah it is. The crash bar (coincidentally) is the same thickness, so itll be easy to mount that way. Its a little off center now so were prob gonna have to take off and re weld (possibly) I havnt got the bumper all the way on yet to tell for sure.
 
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