Martek turbo

[Stuey]

My project been under construction for a couple of months some way to go will be asking for help as never built a turbo before 

Edited October 24, 2025 by Stuey

[1100n]

looks great, looking forward to seeing the project progress

 

[Cookie]

What a beauty, wil folow the progress.

[Maggotbreath]

That's incredible, thanks for sharing! Do you have any more pics? How long have you had it? Carbs or injection? lol, million more questions.

[Stuey]

I got it a few months back from Mark Walker in a deal for my Martek RG500, the engine came from a customer of his who swapped it for one of his frame kits according to Mark.

I pulled the top end and its freshly bored with Busa pistons and oversize stainless valves. I measured the Squish as 1mm and the CR is about 8:1. I'm fitting some GSXR1000 throttle bodies which needed re spacing 550cc Bosch injectors and a Maxxecu. I'm part way through building the loom and programming the ecu fuel tables and other settings at the moment. G19 engineering are making the plenum and I'm making the exhaust with some help from a welder friend.

The turbo is a pulsar X2871R.

I've had to cut the sump out the tank to clear the frame, heres a picture of the tank and seat I'll be using.

[ColinH]

Lovely looking build and will follow with interest. 

[Stuey]

Got the turbo clamped in place ready for the headers to be made. Tried it higher but there is no way with this frame to provide tyre clearance under compression with this size turbo. Going to need to run an oil pump for the turbo return feed but not really a problem.

[Gixer1460]

Beg to differ - there are alternatives that could be tried. Turn turbo around so inlet is on RHS and Exh inlet faces engine and you could raise it to almost exhaust port level - VERY short pipe runs for excellent response / minimal heat loss, Gravity oil drain possible, Boost up pipe on RHS so looks different, wheel clearance better. There are always alternatives . . . . . . . possibly LOL!

[Stuey]

Yes we tried it high and turned around but it really didn’t fit maybe if i cut the frame cradle etc but I feel like Ive got enough to do as it is so for this build it will be as per the picture maybe in the future 

[Stuey]

 

tank all welded up having removed the sump to clear the frame and the fuel outlet and return welded in

 

 

[ColinH]

1 hour ago, Stuey said:

 

tank all welded up having removed the sump to clear the frame and the fuel outlet and return welded in

 

 

Always good to get the tank tackled. Proper fuel line connections as well. I still have to decide if I use existing or make one at the moment.

Keep updating, helps motivate us others. 

[Stuey]

Headers all tacked up ready for finishing 

 

[Stuey]

First positioning of intercooler and underseat oil cooler with the fuel filter and pump on the outer seat rail all looking quite tidy at the moment just need to make up some brackets etc to fit them all properly

 

Fir

Edited December 24, 2025 by Stuey
Added text

[Gixer1460]

Whilst it may not look 'cool' these days - a rear wheel hugger will definately save your cooler, if not your engine from stone impact / puncture damage!

[Dezza]

A bit of wire mesh will give a belt-and-braces approach to cooler protection with a hugger but I'm sure you're aware of that already. That's what I did with my underseat cooler

[Stuey]

Working on the battery box and ecu holder

 

[Stuey]

Making some progress on the overall build so many things still to do 

 

[Stuey]

I'm very new to the world of turbos and FI so this is my first attempt at creating the ignition and Lambda target tables for the MAXXECU I'm using, any helpful guidance would be very gratefully received. I'll be using the auto tune function to set the fuelling when I finally get it running. Be kind this is all new to me having been racing a TZ350 for the last few years.

[Gixer1460]

Don't look too bad ! If I could suggest anything, i'd pull back the timing at top rpm's and particularly in the higher boost range, and increase it in the lower/mid rpm / off & low boost range. As regards AFR, I can't relate to lambda numbers - my brain works in 11:1, 12:1, 13:1 type ratio numbers but mostly the map looks rich even low end & off boost. A turbo engine will give optimal power at same numbers as NA but people / tuners seem to throw large gobs of fuel in . . . . . because its 'safer', which can be proven is incorrect! A too rich mixture can just as easily detonate! Personally I like to keep around the 12:1 ratio as max rich on boost with high 12's / low 13's for most areas except cruise where leaner is possible.

Note : these are applicable to my engine / turbo install and were worked out with extensive step loaded dyno work - more than several days. From what i've seen, if the fueling is 'right' with reduced timing, it doesn't change much with increased timing until its TOO much. So, add/subtract fuel first to get best power then add timing to improve the overall output.

[Arttu]

2 hours ago, Stuey said:

I'm very new to the world of turbos and FI so this is my first attempt at creating the ignition and Lambda target tables for the MAXXECU I'm using, any helpful guidance would be very gratefully received. I'll be using the auto tune function to set the fuelling when I finally get it running. Be kind this is all new to me having been racing a TZ350 for the last few years.

Not badly off I would say. 

For the ignition table I would suggest a couple changes. More timing for off-boost rows, maybe up to 35-36 degrees. Then I would add a column for your target idle rpm, like 1300rpm and set timing there to 10 degrees or so. Them ramp up timing on rpms below that by few degrees. That stabilizes the idle. Also I would  reduce timing between 1500-2000rpm.

Lambda table looks pretty ok but I would set the off-boost areas above idle somewhat leaner, maybe 0.9-0.95. Basically you want set the cruising areas as lean as you can while still keeping the engine running smoothly. 

[Stuey]

Thank you both for the replys very helpful and nice to know I wasn't in a completely bad place, I'll update the tables and then re post them but very much appreciate the help with this.

[Stuey]

OK I made the changes based on my understanding of your comments please feel free to tell me if you think I misunderstood anything, I'm working on the basis that 0.8 lambda is 11.8 and 0.95 is 14 ratio wise. Thanks again.

[Arttu]

Yeah, pretty much like that. 

I would still change the 1000rpm ignition timing column to 12 and 750rpm to 14.

On lambda table you may want slightly richer mixture for the idle area. But that's something what you have to try and see what the engine likes.
 

[Stuey]

So headers are finished and turbo test bolted to ensure fit, it all looks good and leaves room for the intercooler above. Next job is making the exhaust pipe and fitting the intercooler, really pleased with how its coming together

[GSX1100dreamn]

On 1/18/2026 at 12:40 AM, Gixer1460 said:

Don't look too bad ! If I could suggest anything, i'd pull back the timing at top rpm's and particularly in the higher boost range, and increase it in the lower/mid rpm / off & low boost range. As regards AFR, I can't relate to lambda numbers - my brain works in 11:1, 12:1, 13:1 type ratio numbers but mostly the map looks rich even low end & off boost. A turbo engine will give optimal power at same numbers as NA but people / tuners seem to throw large gobs of fuel in . . . . . because its 'safer', which can be proven is incorrect! A too rich mixture can just as easily detonate! Personally I like to keep around the 12:1 ratio as max rich on boost with high 12's / low 13's for most areas except cruise where leaner is possible.

Note : these are applicable to my engine / turbo install and were worked out with extensive step loaded dyno work - more than several days. From what i've seen, if the fueling is 'right' with reduced timing, it doesn't change much with increased timing until its TOO much. So, add/subtract fuel first to get best power then add timing to improve the overall output.

Finally say what now!? something we agree on :-)

A guy at work was discussing his aftermarket ECU and his Lambda numbers from the dyno and I said say what now. But what is the air/fuel ratio, oh you need to convert to know that.

But but, I had a mild stroke and he said you can set the ECU to show air/fuel readings as well, ok then.

Horses for courses I guess, just felt old really.