GSX1400 engine Turbo project

[Joseph]

Hi

Mentioned in the oil cooled section.

I have a GSX1400 engine I would like to convert to carbs and then turbo

This will be the outlet for my technical findings and questions about this engine.

- Ignition :

I figured that if possible, fitting an ignition plate and rotor from a Bandit would be a good way to get rid of the big wiring system and complex ECU of the 1400, so i could just run the B12 ECU and trigger.

GSX 1400 rotor :

B12 rotor :

So far that looks doable without too much trouble. The plate is the same.

The actual timing needs to be looked at, because B12/GSX don't line up, but am I right in thinking that Turbo systems like a bit of retard anyways ? So i need to address that anyway.

- Carburetors :

Off the bat i'm thinking BST36

The 36 are cheap and common, would they seem ok for the application ?

That said, the BST38 would fit on the GSX inlets perfectly (i tested with a spare 40 body i have lying around)

The problem i'll be facing however is the carb spacing :

It is officially 72-110-72 on the 14, which is a major ballache, since the oil cooled ones are 78-90-78.

Also, the 14 inlet rubbers are a weird offset shape :

The spacing matches oilcooled inlets, but obviously the hole doesn't line up.

So not possible to mix and match inlets to fit an oil cooled rack.

Would it be feasible to make the inlets out of alloy, and use silicone hose sections to join the stubs to the carbs ?

 

Edited September 9, 2022 by Joseph

[clivegto]

Don't see why not. Or space the carbs. 

Edited September 9, 2022 by clivegto

[Joseph]

Obviously  Me being thick again.

Looks like it'll have to be both, because the inlets have the rubber bead that slots into the carb groove, but for some reason not as deep as oil cooled inlets so the carbs probably won't be clamped on properly for boost

Drawing board time >>>

[Tony Nitrous]

Oldskool style seperate carbs with a 1 into 4 cable would be do able and bypass any spacing issues. 

[Duckndive]

Why not keep the Fi ?

1400s are a bit gasping when pushed  on Fi with a turbo I doubt carbs would be any better 

[Joseph]

Yeah i see what you mean but isn't that somewhat down to the size of the small 34 TBs ? 

A bandit engine would have been easier, but the 1400 do give quite healthy results though, and i could do with the extra torque of the big CC.

Plus as standard it has got low CR, forged pistons, and a 6 speed Busa box.

I don't want the hassle of FI, i mean, granted, i'm probably giving myself more hassle with a carb conversion  but it gives me issues to solve that i'm more familiar with somehow.

Also, all i got was the engine. No ECU no TBs, no sensors etc, so it will cut costs to source a set of carbs rather locating whats missing from the original set up.

Parts for these are not cheap i have found 

Edited September 10, 2022 by Joseph

[Duckndive]

2 hours ago, Joseph said:

Yeah i see what you mean but isn't that somewhat down to the size of the small 34 TBs ? 

 

Small TBs and ports Yes....But they will make 350hp + BigCC have done a few 

TBH i did wonder from you pic if you only had the bare engine ....and i assume it's going in an alternate frame....? 

A Draw Thru Turbo would be the easiest for simplicity but not everyone's choice ..

[Joseph]

Yes, Holeshots offer kits that claim 200 RWHP on standard engine internals, 250 on standard engine internals + Kentcams (both @ 7 psi) and 350 with all that + turbo pistons and Carillo rods (@ 21 psi)

They all use uprated injectors, custom injection Maps etc

As far as I am concerned, i'm planning on standard engine, with either a Garrett GT2560R :

Or a Garrett GT2860R :

I am hoping for 200-250 HP

The engine will have an air/air intercooler.

Does any of this seem reasonable ? 

Edited September 10, 2022 by Joseph

[Joseph]

8 minutes ago, Duckndive said:

TBH i did wonder from you pic if you only had the bare engine ....and i assume it's going in an alternate frame....? 

It's not going in a bike 

So room for stuff like big IC and OC can be found 

Edited September 10, 2022 by Joseph

[Duckndive]

3 minutes ago, Joseph said:

I am hoping for 200-250 HP

The engine will have an air/air intercooler.

Does any of this seem reasonable ? 

You need an Adult to answer that i only do childish Draw Thru's  

[Tony Nitrous]

7 hours ago, Joseph said:

 

A bandit engine would have been easier, but the 1400 do give quite healthy results though, and i could do with the extra torque of the big CC.

 

I know it’d mean sourcing all the externals, but as a comparison I use my 14 back to back with my Bandit. 

The Bandit motor is a bit lighter, and easier to find parts and upgrades for, but the 14 has noticeably more grunt and fuels much better. I’ve had more issues and work with my (admittedly 1999) Bandit carbs than my 14’s injection. Normally aspirated the 12 would be easier to find some horsepower with its history, popularity and GSXR family, but even without throwing money at less restrictive cam’s, the 14 responds well to a Yoshi or Akra full system, a Powercommander and some dyno time and the stock injection seems up to the job unless you’re after huge numbers…. but then you’d have a Busa motor anyway.

[Joseph]

I've also read about the good gains of a full exhaust on a 1400, but since this is due to be turbocharged that's not a path i need to take.

Busa engine is still too expensive to buy, although indeed performance parts are extremely common. Also its one of those engines that has to be drysumped in my application, and, well...

Edited September 10, 2022 by Joseph

[Tony Nitrous]

41 minutes ago, Joseph said:

I've also read about the good gains of a full exhaust on a 1400, but since this is due to be turbocharged that's not a path i need to take.

Busa engine is still too expensive to buy, although indeed performance parts are extremely common. Also its one of those engines that has to be drysumped in my application, and, well...

I’m a huge Busa fan, I have Gen-1, 2 and 3 powered bikes here. It’s my default go-faster answer ! 

Yeah, my 14 has a full Yoshimura Cyclone, PC111 and some dyno time and is surprisingly healthy. Mildly tuned 14’s do respond well to a good pipe. 

I’ll follow your posts with interest. Although the 14 isn’t an ideal powerhouse it’s a good solid lump is reliable and grunty, mine won’t get butchered as it’s so nice to use as it is, but I’d love to find another to tinker with.

Good luck with the project and I look forward to updates. 

[Joseph]

Back to a few basic questions.

Namely :

Inlets :

If using BST36, thats a 42 OD 36 ID spigot on the engine side.

If i do make alloy inlets, i need a flange to weld the stubs in

3mm wall stubs. 

Alloy question : what thickness should  the flanges be ? Should i anticipate warping of the metal during welding ?

- - - - - - -

Turbo plenum/airbox :

I'm planning on 3mm alloy, looks like thats what was used on my turbo slabby

I'm making plans for laser cut panels to be seam welded on all the edges

Purely technical question :

For this kind of metal, would this the way to position the panels in order to weld for optimal solidity ?

[Blower1]

56 minutes ago, Joseph said:

Back to a few basic questions.

Namely :

Inlets :

If using BST36, thats a 42 OD 36 ID spigot on the engine side.

If i do make alloy inlets, i need a flange to weld the stubs in

3mm wall stubs. 

Alloy question : what thickness should  the flanges be ? Should i anticipate warping of the metal during welding ?

- - - - - - -

Turbo plenum/airbox :

I'm planning on 3mm alloy, looks like thats what was used on my turbo slabby

I'm making plans for laser cut panels to be seam welded on all the edges

Purely technical question :

For this kind of metal, would this the way to position the panels in order to weld for optimal solidity ?

About welding, if you look any factory made pressure vessels, those are all welded together with butt welds.

So hammering the panel edges round about 45 dgr. and then weld in the middle. That way you can use 2mm wall thickness.

There should not be any sharp edges on the plenum

 

[Gixer1460]

18 hours ago, Duckndive said:

Small TBs and ports Yes....But they will make 350hp + BigCC have done a few 

Not easily though! And their Litre class bike engines have often made 500+whp ! That says a lot to me! 

[Gixer1460]

3 minutes ago, Blower1 said:

About welding, if you look any factory made pressure vessels, those are all welded together with butt welds.

So hammering the panel edges round about 45 dgr. and then weld in the middle. That way you can use 2mm wall thickness.

There should not be any sharp edges on the plenum

Deffo agree with this - minimise 'box section' joints as much as possible, ie rounded tank ends, using round tube rather than fab'd up boxes. Even good welding can be blown apart under boost pressure but good welding will definitely survive longer than piss poor efforts LOL! And cure for distortion of the flanges either secure to head or a fixture before / during welding or make them thicker, allow for distortion and mill flat & true after! Or just use turned spigots that fit into std. rubber inlet manifolds, then minor distortion is not a big issue.

[Joseph]

15 minutes ago, Gixer1460 said:

Not easily though! And their Litre class bike engines have often made 500+whp ! That says a lot to me! 

Well i guess thats down to the cylinder head design ?

Anyways, there is always better, but here the victim is a 1400 and the aim is to achieve best output for as contained a budget as possible (if possible)

 

Duly noted for the inlets, i think with what access i have to things, all alloy with a bit of milling will be the most straightforward

The airbox info makes fabrication a bit more complex for me however 

Is the non box joints system to aid flow/strength/both ?

Regardelss, the weld quality will not be questioned, i do have a most excellent alloy welder guy at hand for these jobs 

Cheers

Edited September 11, 2022 by Joseph

[Gixer1460]

Regarding 'airbox' or more correctly Plenum, flow or ease of flow and correct distribution of air to all inlets is important in that it is free power, ensuring correct air to each cylinder equalises power meaning no one cylinder has to be richer / leaner to run right. But as said air pressure stacks up against any joint and the pressurising / un-pressurising will fatigue joins over time if excessive pressure is used. Being conservative with boost helps or over engineering the piece if over boosting often will be a requirement. Most any arrangement will be ok at 1bar and if pushed 2bar but above that any 'simple' construction - all bets are off LOL! There are plenty examples of alternative plenum designs used successfully AND some that weren't - pick what will work for you and copy it, and you won't be far wrong, I copied my first one from a Hahn Racecraft design, I drew it up and had it fab'd up - its still going strong as far as I know, some 30 yrs later!

[Joseph]

Right so this turned up from the cutters

The top edge will be rounded using a quarter cut off a 60mm tube

[Joseph]

Right

I'm back at this.

I've worked out what needed doing to respace the carburetors, and the bits are currently being machined by the guy who does that for me cause lets face it even if i did have the tools to do it...

I've chosen mk2 bandit 36mm carbs,  because the intake side is round, not oval like on the mk1, seemed more sensible since i'm plugging silicon hoses onto them.

As far as spacing goes, it turns out that when fitting onto straight intake spigots, you can get away with only spacing carb 2 and 3 further apart.

1-2 and 3-4 have 2mm more on the Bandit rack so i should be able to squeeze them onto the spigots 

They've been taken apart and had a noisy bath, so they're now relatively clean, waiting on the rebuild kits and larger main jets

One question i have for you is :

While we're at it, I think it would be worthwhile renewing the butterfly shaft O rings, since this rack is getting pressurized ?

Is this what you all do and also, is it a prudent job to undertake ?

I've also cut down the alloy trumpets i had for another project, and the 8 machined spigots for the plenum and intakes are on order too.

[Joseph]

Also the trumpets will be 20mm high in the plenum, and i calculated 6500cc internal volume for it. Sounds good ?

[Joseph]

Meanwhile, the carbs getting renewed

That main jet is probably going to be obsolete though 

[clivegto]

Wondered about doing the butterfly seals but never bothered. 

[Joseph]

Well thats good 'cause i've scored the web and nobody has the size required (8x11.5x2.5)