Xmt - Sarty's Xsara GTI6 Turbo

[DrSarty 98 1 Cars]

And will one of the mods PLEASE change this topic title to GTI6 instead of Mi16.

 

It should also be 'Xsara XGT' as a result.

 

There is nothing Mi16 about this build, other than it probably being an ancestor of the GTI6. Plans changed... as they do.

 

It's a GTI6 block (bored out), a forged diesel crank, a GTI6 inlet & a modified GTI6 head, bolted to a VTS 'box (with Quaife). From an engine perspective, everything else is custom. It's barely even a GTI6!

Edited January 9, 2024 by DrSarty

[pug_ham 245 3 Cars]

3 hours ago, DrSarty said:

And will one of the mods PLEASE change this topic title to GTI6 instead of Mi16.

Done.

 

g

[DrSarty 98 1 Cars]

Thanks G.

 

Questions: I've never really understood why some cars have a vacuum pump. They are typically run off the end of a camshaft. I've removed mine from all of my Naturally Aspirated (N/A) builds as the vacuum/servo assist has always come directly from the inlet manifold & I've never had an issue with braking assist.

 

1. Why are they used, especially on N/A cars?

 

2. IF they were there explicitly for Forced Induction (F/I) cars - turbo or supercharged - which clearly they are not, I'd perhaps understand it, as PERHAPS the manifold pressure situation is different on F/I cars. But as this engine is turbocharged, (a) do I need a vacuum pump & (b) if not, how do I supply vacuum to assist the servo?

 

I'm sorry if this is a dumb/already covered question.

 

EDIT: Started to do some research. I think I'm going to get & use an electric vacuum pump:

• This video plus some useful text below

 

Edited January 12, 2024 by DrSarty

[DrSarty 98 1 Cars]

It's ALIVE!

 

10+ years in the making, although most assembly work has happened in the last 2.

 

It started first time, but of course there are stories about that & the busy build work of late. Detail & photos to come.

 

Here's the engine bay as it stands. Some final wiring tidy up work to do soon (bottom right & top right).

 

Huge thanks go to Goliath, Welshpug & 'Jez' (don't know his forum name, but he's finishing a 405 V6 in the same workshop), & numerous other contributors too many to mention.

 

It sounds mean, like a WRC car on the start line. Lots of further setup & mapping to come, but it should be on the road soon.

 

Summary/reminder of the build:

- GTI6 head

- 87mm bored 2.0L block

- Forged crank, rods & pistons

- 2.3L capacity with 9.3:1 CR

- Inconel (sp?) valves

- Some porting & flowing

- Custom, equal-length runner exhaust manifold (wrapped)

- Custom, stainless full exhaust post-turbo (some ceramic-coated)

- Owen Developments ball bearing turbo

- Turbosmart wastegate, oil & fuel pressure regulators & blow-off valve

- Quaife ATB

- Emerald K6 ECU, with wideband lambda & custom loom

- Custom fuel rail & 846cc injectors

- Modified Nissan 350z intercooler

- Mocal oil cooler

- Volvo vacuum pump

- Saxo 50mm thick rad with twin Spal pull fans

- Already has the lovely 2.3 turn VTS quick rack with hydraulic PAS

- 4 port electronic boost controller

- Added boost & oil pressure gauges

 

I'd also like to hand out big cheers of admiration to anyone who has done or plans to do something like this, especially with a high degree of customisation. Even adding a turbo or supercharger via an off-the-shelf kit is quite a big job. Hats off to anyone who's crazy enough to do things like this.

 

Hopefully 400bhp & similar - if not 20% higher - torque figures will be achieved. But at least it runs already & is ready for final steps including mapping.

Edited March 10 by DrSarty
Corrections

[Jer309GTi 3]

Can't wait to hear it, glad you've got it going! (I'm the one with the 405 v6)

Passenger ride when it's on the road please!

[Tom Fenton 1,559]

Are you using a BE or ML gearbox? Reason for asking is from a lad we know with a GTI6 turbo, you'll almost certainly destroy a BE at that sort of power output. In particular 5th gear is really weak due to its position hung off the end.

[DrSarty 98 1 Cars]

It's a BE, & I'm aware it may be the weakest link. We'll see. Plan is not to beast it so it breaks, ie a settling in period.

 

I'll look into ML replacements & hopefully do it as a proactive swap, rather than a fix next year.

 

Lots of/lots more travelling to do this year!

 

Last year I visited 30 countries (including 26 in under 80 days). Next week I'm doing a 500 mile walk across the Pyrenees, then later in in South Korea, Vietnam & Australia.

 

I need to find some time in late 2025 to drive the bloody thing!

[petert 607]

Well done. I'm wondering if you'll max out the 846cc injectors? Which of course means it's making HEAPS of power. Don't forget to call in

[Ron_Jaegers 12]

Really cool build this! Can't wait for video and audio.

 

If you travel that much and plan to stop in the Netherlands maybe you can take over my ML6c (20mb04) gearbox. Should be plenty strong to handle serious power. Caveat: it's now mated to an EW and will need customisation to get it to work on a XU. But the experts here might be able to help.

 

Good to see these projects being finished. Gives me hope I will once finish mine as well.

[stef205 93 1 Cars]

9 hours ago, petert said:

Well done. I'm wondering if you'll max out the 846cc injectors? Which of course means it's making HEAPS of power. Don't forget to call in

id say the opposite, a quick calculation would say roughly only 600cc is needed for 400 horse. Our 550's are over kill at 400 horse 

[DrSarty 98 1 Cars]

PeterT - Defo. We missed each other last time I was in Sydney, so let's make sure it happens this time. It'll be from July 8th to early August. Maybe meet in the Bavarian beer place again?

 

Ron - Yes please!!! The Dutch contingent here are a great crowd & with Goliath/George, I have quite a lot of contact. Stayed at 'Sander's' place recently after driving an M3 over.

 

Stef - I'm inclined to agree with you, ie not use over 800cc/min, however some online calculators indicated I'd need close to that. I thought about 600, but when some calcs showed more than that, plus people saying modern injectors of 1000cc+ still give good low rpm resolution, I thought I'd go big to be safe.

 

Thanks for the comments.

[SRDT 194]

On 3/11/2025 at 11:23 AM, DrSarty said:

I'm doing a 500 mile walk across the Pyrenees

Excellent choice... but maybe I'm a bit partial here.

 

As for the ML6C it exist with the correct bellhousing pattern but your engine will then lean at 18.5° to the back instead of 30°. Oil pump pickup and oil pan can be sorted using 2.0 HDI parts but there is a lot of stuff to move around in the engine bay.

[petert 607]

On 3/12/2025 at 6:45 AM, stef205 said:

id say the opposite, a quick calculation would say roughly only 600cc is needed for 400 horse. Our 550's are over kill at 400 horse 

I was thinking E85. Very popular here now.

[petert 607]

On 3/12/2025 at 8:05 PM, DrSarty said:

PeterT - Defo. We missed each other last time I was in Sydney, so let's make sure it happens this time. It'll be from July 8th to early August. Maybe meet in the Bavarian beer place again?

Anytime after 10 July suits me. Or that gin bar?

[DrSarty 98 1 Cars]

Dunno if this'll work. Wear good headphones or use decent speakers please.