Questions about correct twin turbo+carb set up '85 GL1200

[JeffReyJR]

Hello all.
Not sure if I've introduced myself already or not (likely not) my (internet) name is JeffReyJR.
I'm just some bloke that like many other long time lurkers, finally created an account in hopes of getting even more helpful tips as well as being able to interact and must say this is the coolest Goldwing (if not motorcycle in general..) Forum I have found so far.

So as far as what I'm trying to figure out through here goes..
I have an '85 GL1200 interstate that I'm stripping, rebuilding, and frankenstiening (If you're in the DMV area and want the outside bits hmu).
Part of what I want to do with this build is to add not just any, but a well set up turbo charger system ( thinking twin scroll system if I can find an affordable one) to increase the power (even if I'll never use it all ) and fuel efficiency.
I see a lot of supercharger options for these bikes but superchargers seem to have the opposite effect on fuel economy and just aren't what I'm looking for.
Which leads to the real question.

What I want to figure out is this: What is the optimal cfm/turbo size for this type of bike, Does anything else (aside from rerouting exhaust and intake into being a turbo system) need to be done if the turbo is added such as reinforcing or balancing, and what kind of carburetor set up best lends itself to a turbo application?

Any help with any of these questions would be greatly appreciated and I feel from what I've seen on here that if anybody could help, it would be you fine folks.

[olchris]

mmmh ... Dont forget to change the belts!!

[robin1731]

You might check the unique carburetion section. And the custom section. Other than that there isn't a lot of turbo stuff already done. It will be all custom. As far as sizing the turbo up the best way for that is to go a turbo manufacturer and check their tables. I would guess most of them have a chart for that. Or at least a tech line that you can call. I would go by that more than any internet forum. Unless you know the person has lots of experience any info can be iffy.

Ask about nitrous and I can help you there. I've been around that on bikes for many years. I've been around some turbo bikes too, a funny bike I used to do some clutch work on. But I wouldn't try to tell you how to set one up.

Oh, and no, you didn't do an intro. Always good form to do that. Say hello and ell us a bit about you and your bike in the introduction section's.

[JeffReyJR]

You might check the unique carburetion section. And the custom section. Other than that there isn't a lot of turbo stuff already done. It will be all custom. As far as sizing the turbo up the best way for that is to go a turbo manufacturer and check their tables. I would guess most of them have a chart for that. Or at least a tech line that you can call. I would go by that more than any internet forum. Unless you know the person has lots of experience any info can be iffy.

Ask about nitrous and I can help you there. I've been around that on bikes for many years. I've been around some turbo bikes too, a funny bike I used to do some clutch work on. But I wouldn't try to tell you how to set one up.

Oh, and no, you didn't do an intro. Always good form to do that. Say hello and ell us a bit about you and your bike in the introduction section's.

Took your advice and got off of craigslist to check manufacturers websites to see what actually exists. Narrowed it down pretty quick as the options for such small hp ( Never thought I'd use the word small when describing a goldwing..) are very limited. So far it seems that the Garret GT1241
is my only option for this bike.

Not a twin scroll system but hey, if it works it's better than nothing.

There is also the GT0632SZ
but with the hp range topping off at 80 and the displacement rating maxing out at 0.5L I worry that it would be destroyed.

I wonder if a variable twin setup would work with the two... I don't know if the air would bypass the smaller turbo at higher rpm (and save it from destruction) or simply blow it out in that kind of a setup...

Or maybe I should just check myself before I wreck myself. Figuratively, literally, and financially..

Also, I can't find intercoolers for that size. Are they needless on such a small turbo or are they still important but not manufactured?
This rabbit hole just keeps getting deeper..

[JeffReyJR]

You might check the unique carburetion section. And the custom section. Other than that there isn't a lot of turbo stuff already done.

Already had a gander or two through a lot in those sections but as turbos aren't often found, peoples carburetor+turbo setup experience is hard to come by.
I guess I'll have to just study the carb options harder and fiddle with different hypothesis'.
If I figure anything out along the way I'll try to be sure to post it but for now I suppose it's time to comb through those forum sections more carefully and take some notes.

[ericheath]

A BMW which is Mitsubishi from a 3.0 liter twin turbo would be close. I have one when I had some crazy ideas. It's sitting in a box and needs a rebuild. They are said to be less peaky than others. Some BMW owners complain because they don't feel the jolt of it when it spools up, but its numbers are pretty nice across the range. Mine is a td3l 4w 10tk3-4.9. Wish I had a clue as to what it means. I would think you'd want Efi to be safe. Gonna cost you a grand at least when you figure it all in.

[JeffReyJR]

. I would think you'd want Efi to be safe. Gonna cost you a grand at least when you figure it all in.

I'm not well versed in fuel delivery systems.
If you don't mind expanding, why would I want the efi?

So, take a 3L twin turbo, use just one of the turbos, and it's a 1.5L turbo?

[ericheath]

You find guys on the net who carb with turbos, but one mistake and they go poof pretty easy. EFI reduces the chances. Have you seen irishcarbomb's build? He is the most recent I know of to do it. Someone else here has one in the works with a Weber sidedraft. I really wanted to do it, but the more I read about it, the more I realized it's a delicate thing with carbs. And EFI is expensive when you get all the parts, and then you have to tune it. The Turbo might be the cheapest part. I am finding jetting without a turbo challenge enough. I should plunk down the money for a O2 sensor and maybe it could be sped up

Another negative to a turbo on a Wing is the fact that you won't be able to use much of the boost. There's a pretty good body of evidence that spun bearings happen with too much boost. Pinning them is a big job.

Sunnbobb is getting close on what might be the best bang for the boost buck using an Aisin supercharger. If you want to plunk down money, see Casper's build. It's close too.

They each have put it into pics and writing enough to know that it's not your average driveway swap. Not discouraging you. Hope you can and start a build thread on it.

[JeffReyJR]

You find guys on the net who carb with turbos, but one mistake and they go poof pretty easy. EFI reduces the chances. Have you seen irishcarbomb's build? He is the most recent I know of to do it. Someone else here has one in the works with a Weber sidedraft. I really wanted to do it, but the more I read about it, the more I realized it's a delicate thing with carbs. And EFI is expensive when you get all the parts, and then you have to tune it. The Turbo might be the cheapest part. I am finding jetting without a turbo challenge enough. I should plunk down the money for a O2 sensor and maybe it could be sped up

Another negative to a turbo on a Wing is the fact that you won't be able to use much of the boost. There's a pretty good body of evidence that spun bearings happen with too much boost. Pinning them is a big job.

Sunnbobb is getting close on what might be the best bang for the boost buck using an Aisin supercharger. If you want to plunk down money, see Casper's build. It's close too.

They each have put it into pics and writing enough to know that it's not your average driveway swap. Not discouraging you. Hope you can and start a build thread on it.

Thanks man. I appreciate the thorough response
Seems I have a lot to think over now and I'm glad I'm not going to waste as much time by starting this project flying blind.
If I happen to follow through I will take pictures and make a post but for now I will probably stick to other things and try to complete a build without the turbo. I figure if I decide later I want it I can just add it and tweak other things, but if I do it right in the middle of the build and have issues (I will likely have many issues w/or w/o it) than it would be more difficult to track down the issue.

Going to be looking into those EFI systems though.

[ericheath]

I have an 85 1200 in my 1000. It has 1000 heads, cams and carbs. It goes fast enough. The 1200's were the fastest of the lot I think in stock form. The 1000's were still from the two valve per cylinder era and bigger and more air made the most horsepower back then. I think mine probably makes more horsepower and probably torque too than a stock 85, but at higher rpm ranges. When the 1200's came out, there was a different theory evolving with smaller intake tracts and more velocity going in to give better bottom end performance. It also was the advent of maintenance free valve trains. I personally think Honda wanted to move the rpm range down to protect the valve train. I have advanced my cams about three degrees of timing to help keep the rpm torque range down.

Some of what I might perceive as an increase in power may be due to the fact that the 1000 was much lower geared. I'll never know unless it's dyno'd.

If you want more oomph from your 1200, that's one way to go. It's going to cost 4-500$ for heads, cams, carbs, gaskets etc. it cost me less because I had the parts. I think the cheapest boost for these in the long run may be the Aisin supercharger that Sunnbobb is doing, although like many things when everything gets thrown in, it costs.

I just came back from a trial run with mine. I have developed some backfiring issues which I thought was exhaust related, but have since found that my air box was leaking badly. Anyways it's pretty close now. I left a stoplight smoothly, when I got to the other side of the intersection, I gave it the beans and the back tire just spun. It's enough power to be dangerous.

[gearhead4207]

I have a stock 1200 aspy full dress and it goes pretty good ive had 1000 1100 and 1200 there all spunky when running correctly but have seen a lot of 1200 swaps into 1000 and 1100 frames almost everyone that has done it has been pleased in the end . Ive never swaped one so I don't know for sure but I do like my 1200 runs strong and don't have to adjust the valves anymore . All though that's wasn't a deal breaker I didn't mind the adjustment its not hard just a process. my 1200 has 80000 miles on it so longevity is on your side with Goldwings have seen them with over 100000 miles on them and still running strong .looking forward to watching your thread and seeing where it goes .

[sunnbobb]

Hi guys, Ive been out of pocket for a couple weeks. I came home to my fabricated plenum for the Aisen. I am one happy camper. I'll post some pics on the Anubis build thread when I get some time. I plan to do some serious work on the system over the next week or two.. You are going to love the solution for the plenum..

[JeffReyJR]

I have a stock 1200 aspy full dress and it goes pretty good ive had 1000 1100 and 1200 there all spunky when running correctly but have seen a lot of 1200 swaps into 1000 and 1100 frames almost everyone that has done it has been pleased in the end . Ive never swaped one so I don't know for sure but I do like my 1200 runs strong and don't have to adjust the valves anymore . All though that's wasn't a deal breaker I didn't mind the adjustment its not hard just a process. my 1200 has 80000 miles on it so longevity is on your side with Goldwings have seen them with over 100000 miles on them and still running strong .looking forward to watching your thread and seeing where it goes .

Any Idea how much work is involved with getting the 1200 engine in a 1000 frame?
On forums I see a lot of " -Can this be done? -No it has been proven that it absolutely can not" kind of discussion even though I also found a few videos showcasing that it has been done...
Unfortunately they don't go into detail and at 240 dpi it's hard to try to eyeball the differences.
But I do want to be sure I have the right frame before I start cutting and such.

[robin1731]

I have a stock 1200 aspy full dress and it goes pretty good ive had 1000 1100 and 1200 there all spunky when running correctly but have seen a lot of 1200 swaps into 1000 and 1100 frames almost everyone that has done it has been pleased in the end . Ive never swaped one so I don't know for sure but I do like my 1200 runs strong and don't have to adjust the valves anymore . All though that's wasn't a deal breaker I didn't mind the adjustment its not hard just a process. my 1200 has 80000 miles on it so longevity is on your side with Goldwings have seen them with over 100000 miles on them and still running strong .looking forward to watching your thread and seeing where it goes .

Any Idea how much work is involved with getting the 1200 engine in a 1000 frame?
On forums I see a lot of " -Can this be done? -No it has been proven that it absolutely can not" kind of discussion even though I also found a few videos showcasing that it has been done...
Unfortunately they don't go into detail and at 240 dpi it's hard to try to eyeball the differences.
But I do want to be sure I have the right frame before I start cutting and such.

A little bit of clearance on the rear frame tube where the rear engine case is a bit close. I think that is mostly it. If you go with the 1000 heads you can then use the 1000 ignition of your choice. That makes it easier too.

Oh, you also need to swap the drive coming out of the engine for the propshaft. Put the 1000 shaft in the 1200 engine. Need to remove the rear cover to do this.

[JeffReyJR]

A little bit of clearance on the rear frame tube where the rear engine case is a bit close. I think that is mostly it. If you go with the 1000 heads you can then use the 1000 ignition of your choice. That makes it easier too.

Oh, you also need to swap the drive coming out of the engine for the propshaft. Put the 1000 shaft in the 1200 engine. Need to remove the rear cover to do this.

Would that mean I have to swap the whole swingarm or just the rod going through it?
Or am I thinking of the wrong part all together?