sierra dohc 16v + turbo

Hi,

I've read this forum many times and also saw a lot of videos in youtube. Your cars are lovely

I started turboing my dohc sierra in 2011, after broke 3 dohc 8v engines (std conrods are shit). My record was 255bhp with changed camshafts @ 1bar and MLS headgasket with some durability.

The sierra I'm talking about is the blue 3door in this pic



After breaking the third engine I swaped to a V6 BOB, I liked it a lot, I was thinking to turbo it also, I tried to legalize the swap but in Spain some things are stupidly difficult. And the lab didn't like a v6 in my sierra (I know.. there were alot of v6 sierras from factory..), I also had a problem with a conrod bearing, so I decided to come back to 2.0, but this time using scorpio N3a engine (2.0 16v)


In this engine I went with maxspeeding rods and C20XE forged pistons. This give me a CR of around 8:1, I don't like this, but couldn't find any cheap option of around 9:1. I could regrind the block but prefered to avoid that.




I know my welding is not the best.. It was my first big job with my MIG welder



















I made a little mistake, read a lot about VGT turbos on petrol engines and end buying a holset he351ve which is supposed to cope well with petrol high EGT's, but i didn't imagine it was as big as it is... I made my own controller, using an Arduino and sending vanes position by CAN commands.. It doesn't spool very well, I don't good boost until I'm over 4500 rpm







holset vs t3 from cosworth 2wd:





I will continue on next post

this was one of the first starts







The ECU I'm using is Megasquirt MS2, but made some testings also with FreeEMS, a good open source project, but it have a lot of work pending. Injectors are from the V6 BOB modded to have more flow. I don't know exactly how much them flows, someting between 500 and 650. I just checked all flowed near the same.

I had some problems with spark wires, so I changed all to VW TFSI COP coils and mod My ECU to suit this. It was a very good mod, I like it.




The engine had done around 1200km but it's not good tuned yet, too much ignition retard, and it's also too much rich on boost. Last week I had a problem with my daily car so I've to get the sierra all week to go to where I live during week (job). I had also water leaks and a problem with my WB EGO, but even with this I wanted to go to a dyno just to see how it was prior good tuning and proper boost.



results were just 236bhp and 315Nm of torque @ 0.8bar of boost . I hope I can improve it a lot. If not I will change the turbo for another smaller.

One of the next mods is installing a supra MK3 LSD diff (3.9:1) in scorpio cosworth rear beam, instead of my cossie 4wd (3.62:1) in std rear beam.

scorpio engine, 2.3 16V ? not 2.0

Thierry skrev:

scorpio engine, 2.3 16V ?  not 2.0

yes, in scorpio there are 2.0 8v, 2.0 16v and 2.3 16v. Mine is the 2.0 16v for the simple reason the block is the same in the sierra, so If i broke the engine, I should get easy a replacement. There are not many scorpios 2.0 16v nowadays in spanish junkyards, but 2.3 is near impossible to get one, is really strange. It's easier to get a 2.9 24v. So I decided to go 2.0 16v route for this reason, because if I install a 2.3 and broke it, could be difficult to replace it

This is what i like, nice projekt!