Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[MikeyBikey]

Hi all. As per my project thread I've fitted a y32se to my scimitar.  I have open headers, straight through 2" exhausts, large k&n, and an aftermarket ecu to switch between lpg and petrol.

It's brilliant and once I've mastered picture hosting and  my new phone I'll post some pictures.

My question is, to gain more power its been suggested to fit higher compression heads from a 2.5 ? I've researched and its clear every engine variant of the v6 has different bores. So how do i identify the correct 11.5 compression heads from all the others and despite differences in bores, will it fit the 3.2

Thank you

[Doctor Gollum]

You've done about all you can with the Omega V6.

The 2.8 turbo would be an option but it's configured for front wheel drive.

2.3 Saab Turbo lump is readily tuneable and gives significantly more power.

[Nick W]

DG is pessimistic as there is plenty more you can do, especially as you don't need the modifications to work in an Omega.


But it is traditional tuning; cams, properly modified(more than 10minutes with a Dremel) heads and better induction. Those are all available, but are expensive and very expensive when you consider the fairly small gains. You need to discuss your intentions with the part suppliers before making any changes.


Just increasing the compression ratio just by itself won't do much

[Doctor Gollum]

Pessimistic is a bit harsh 

2.6 heads will give you the compression, but your limiting factor is getting enough air in to be able to add more fuel.

[Nick W]

Pessimistic is a bit harsh 

2.6 heads will give you the compression, but your limiting factor is getting enough air in to be able to add more fuel.

better porting, bigger valves, performance cams, individual throttle bodies. That should break 300bhp, but will also break £5k.

[Migv6 le Frog Fan]

Pessimistic is a bit harsh 

2.6 heads will give you the compression, but your limiting factor is getting enough air in to be able to add more fuel.

better porting, bigger valves, performance cams, individual throttle bodies. That should break 300bhp, but will also break £5k, and the bottom end.

Fixed. 

[MikeyBikey]

Thank you all. Is another option, maybe, depending on your Informed input,  fitting the asymmetrical turbo  from the 9-5 3.0 petrol turbo.? I have the manifold and turbo, on the garage shelf. With all the extra gubbins (intercooler blow off valve etc,) would it work on a y32se

[MikeyBikey]

I understand as I'm using lpg, having a compression ratio of 10.1 is not an issue with forced induction.

Cheers

[VXL V6]

I believe the main problem with pushing the 54 degree V6 is that the cooling around Cylinder 6 is marginal.

[MikeyBikey]

Thank you vxl. Ironically that's the external location of the turbo, if I were to fit it.

[Nick W]

Thank you vxl. Ironically that's the external location of the turbo, if I were to fit it.

that's a peculiar place for a single turbo, especially in a Scimitar. You could probably swap the standard exhaust manifolds side to side, join the downpipes in front of the water pump and put a big turbo there.


The standard Saab turbo is designed to boost mid-range torque and will run out of puff at high rpm, whereas your use suggests you want more top end

[Raeturbo]

You would probably be better off trying to get a small supercharger on it instead. You won’t need an intercooler if you’re only going to run about 6 or 7 PSI. And every 3.9psi will raise compression ratio by 1 so you can have 11.1 with just 4lbs. Which should give around 30/40 bhp with a nice dollop of torque and broaden the power  band. Don’t know how much room you have there but some of the early toyotas use a nice little unit👍 Of course you will need to get it mapped to get the most out of it.

[Nick W]

You would probably be better off trying to get a small supercharger on it instead. You won’t need an intercooler if you’re only going to run about 6 or 7 PSI. And every 3.9psi will raise compression ratio by 1 so you can have 11.1 with just 4lbs. Which should give around 30/40 bhp with a nice dollop of torque and broaden the power  band. Don’t know how much room you have there but some of the early toyotas use a nice little unit👍 Of course you will need to get it mapped to get the most out of it.

Superchargers are harder to size to application, and much harder to fit especially to a V engine. You also have to consider how much power they absorb to make that 40 hp. That's a small enough increase that could be achieved by aftermarket cams and some head work. Which is simple bolt on work, albeit fairly costly.

[Raeturbo]

Indeed swings and roundabout, second hand sc can be found but how much room is there to fit ....... cams and porting will give you power up the top end.. whilst more boost will give nice midrange shove. I think Vauxhall missed a trick with this engine I feel it could have been a nice 240/250BHP if they used a bit of imagination👍

[TheBoy]

I know the 3.2 has a stronger crank and a lower CR to start with, but remember those idiots at Courtney plopped a turbo on some of the early 3.0 cars, and all quickly suffered bottom end issues.