[nealric]

Nope. There used to be a kit made 20+ years ago and there are a few manifolds floating around. But your best bet is to fabricate one that is up to modern standards.

 

[nealric]

Jenvy throttle bodies come with DCOE bolt spacing. They'll bolt right up to Weber manifolds.

https://store.jenvey.co.uk/throttle-bodies-and-components/throttle-bodies

But how does this answer TS, who is asking about turbo system?

It’s an option to a piece of the puzzle, which is engine management. You really want programmable fuel injection with a turbo, so you’ll need a throttle body.

 

[nealric]

You'll shoot your eye out....:thumbdown:

It's all fun and games until someone blows a head gasket.

 

[nealric]

Here's an option on intake manifold for TS - Intake manifold for Alfa Romeo 75 1.8, 2.0 turbo with 70mm throttle body from Alfa Romeo 75 2.0 TS or 2.5 V6. | Sport exhausts | Exhaust manifolds | Sport exhaust systems | Extreme-Tuning.bg

And an option for exhaust manifold from the same company - top mount or bottom mount available - Exhaust manifold Alfa Romeo 75 1.8,2.0 turbo | Sport exhausts | Exhaust manifolds | Sport exhaust systems | Extreme-Tuning.bg

Thoughts?

Thanks,

Scott

Doesn't look like a bad option. The TS is a better forced induction platform too.

 

[nealric]

A turbo install in a 105 chasis invites all manner of unpleasant compromises due to the location of hydraulics so close to a turbo. Driving such a car in Texas in Ausust will surely prove to be a hard field test for any turbo install.

From the Extreme Tuning site (they are in Bulgaria for cryin' out loud!!!!):

My turbo install didn't really invite any unpleasant compromises on the hydraulics. You'll want a heat shield, and some insulation on the brake lines, but that's about it. Since I've switched to a boosterless setup, there's now quite a bit of room between the hydraulics and the turbo. It's had no trouble heat-wise during the Texas summers, but it does have an upgraded radiator. Honestly, the only limitation on the heat front is my own heat tolerance.

The extreme tuning site is just repeating something that applies to any tubular turbo manifold (or even a header for that matter, but to a lesser degree). A tubular manifold will flow better than a log. Ceramic coating is usually better than a wrap, however as you don't have moisture trap problems.

Biggest weakness is really just the head gaskets, but mine took a pretty decent amount of abuse (many track days, auto X, bouncing off the rev limiter, etc.) before giving up. For anything over 7-8 PSI, you will want to bump down the compression.

 

[nealric]

This company makes copper head gaskets for Alfas. They come in thicknesses up to .125. I've seen one of their 2 liter Alfa copper head gaskets and found it to be of excellent quality. They have designs for normally aspireated Alfa engines and, also, for turbo-charged Alfa engines. Be sure to use Hylomar M as a gasket sealer. Definitely sticky stuff.


Gasket Works - Products

I'm personally not sold on copper head gaskets. They tend to seal fluids rather poorly from what I understand. My solution for the current motor is an o-ringed liner. Will have to have the head back from the machine shop and the car back together before I can vouch for it.

Besides copper, Jim K. has reccomended MLS (multi-layer steel) gaskets as solution for turbo Nords. The advantage is they can compensate for head lift under very high cylinder pressures.

 

[nealric]

Good info. I don't mind running without a booster.

To be clear, running without a booster isn't required. I even did a few track days when I was running with a booster. The catalyst for a boosterless setup was to get a dual master setup with a balance bar so I could adjust brake bias on the fly and have a bit more redundancy in my system.

I never did get around to dynoing my 1.0 setup (100% stock motor at 7psi), but I'm guessing it was around 170-200 ish. It was enough to break the tires loose at will in second gear (more torque than just about any NA nord build). Goal for 2.0 is 300 with the built motor, which should make the car a handful- I will probably run it on lower boost most of the time for reliability and driveability.

 

[nealric]

What are the specs for your built motor? Any head porting? Can you remind us what turbo you're running and your induction?

It's a GT28RS (I'd put on a more up to date G25-550 or Borg Warner EFR 6528 if I were building it today). Intake manifold is custom CNCed and tig welded, and the fuel rail is likewise custom. Turbo manifold is a basic cast log manifold. Engine management (both spark and fuel) is done with a megasquirt 3. Intercooler is a custom core designed to fit behind the spider front bumper- a GTV would probably demand an air/water intercooler due to packaging constraints. I can't claim credit for the base turbo build- I bought the car from A. Georgi on the forum who is responsible for the getting the turbo running.

Head was a bone stock Bosch 2 Liter (no VVT) with stock cams. For version 2.0, I'm having a head built with 1mm oversized valves, some porting/bowl shaping, and some street performance cams. Turbos don't really need head work to make power, but I'm hoping the head work will outweigh the off-boost power loss from bumping down the compression to 8.5:1 and help with spool. Unfortunately, the head work is the main thing holding up the project. It was supposed to be done at the end of last summer, but my head builder had some health problems and other setbacks. I'm also having the chassis painted while the motor is out.

Bottom end for 2.0 will have JE Pistons (8.5:1 compression), O-ringed Darton liners (sold by Wes Ingram), Carillo H Beam Rods, balanced crank, windage tray, Gordon Raymond oil pump, Alfaholics "Rally" billet flywheel and clutch.

My build thread is here:

https://www.alfabb.com/bb/forums/sp...pider-105-115-series-1966-1994/472713-better-boost-my-turbo-spider-journey.html

 

[nealric]

For some reason, I thought the 1.8 exhaust manifolds were different, but it’s fairly likely it could be modified to fit under worst case scenario.

If you order, let us know how those manifolds work out. Bulgaria isn’t exactly a traditional location to find Alfa parts, but they do at least look nice and are priced as relatively premium products.

 

[nealric]

I think for European folks the 1.8 is a clear winner. I ended up going with a standard Nord because it was looking like $2k to get a 1.8 motor shipped from Europe, and I’d be taking the risk of damage or getting a bad core. Then I’d also have to deal with sourcing other internal components like forged pistons from across the pond. Since 2 liter cores are practically free here, you can buy stronger liners and forged internals for the difference.

I think you could make a 2 liter at least as strong as a 1.8 with a good deck plate and better liners. I just wish there was an off the shelf option. Driving a Subaru STI makes me a little jealous comparing what’s available for the two motors.

 

[nealric]

sensible decision. I never seen the use of turbo in 105 chassis (yes I know the GTA SA....). Besides that you need the very long gearing of f.e. the berlina automatic (easy to find....)...
Seen a few going sideways (to far...)
Friend of mine did build one long ago (before the www existed...) sold it off, not very noce to drive. Other one was totalled , going straight on a wet motorway... (still not cleared why as far as I know...but probably due to tarmac imperfections..).
nice torque of TS will make a nice driver (which still does well in modern traffic)

If a car wasn't nice to drive, I'd suggest it was a problem with the build. Old school turbo builds with carburetors and old slow spooling turbos have serious driveability problems, but modern turbos with EFI drive very nice. I'm obviously biased, but I think my car is a hoot.

The gearing is an issue given that anything taller than the 4:10 spider rear end is very rare. I've come to like the short gearing except for autocross where the car seems to want to always be between 2nd and 3rd gear, and also on the freeway where it really doesn't need to be turning 4k rpm to cruise.

If the car is going sideways too much, it's a suspension, diff and/or tire issue. You wouldn't want to run 165width tires with a turbo car! A worn stock LSD might as well be open.

Still, a built twin spark should be quite nice, and a much easier project.