Sniper EFI blow thru turbo

[Stumps 369]

Hey guys.

 

Looking at turboing my 74 XB, the old log motor is getting replaced with a 30thou over 2v motor, which is currently fitted with a 214 degree cam.

 

Im looking at ditching the pistons for some low comp items so I can run a Gt3576R Turbo and intercooler.

 

On the induction side i was looking at using a Holley sniper 2300 TB efi setup, and ICE ignition for spark control.

 

I was planning on using the factory cast iron manifold with a J pipe fitted.

 

Would this setup work on the 2v pre Xflow, anybody have any suggestions? 

 

Im hoping for around 220rwkws so the XB can match my G6 ecoboost GTX2863r combo in a straight line.

 

[gregaust 334]

Just used a sniper on 427 small block , blow thru with a Vortec V7 . Using the Sniper is a great setup for fuelling, almost too easy 

[Stumps 369]

What sort of manifold did you use? I've heard about fuel pooling issues with manifolds that have smallish plennum areas.

 

I was thinking of using the 2300 2bbl unit on my 250 2v and upgrade the manifold to an aussiespeed one with a larger plennum than the factory manifold I current have.

 

From what I have seen on Holleys website the 2300 should support up to 650hp boosted...hopefully that isnt a misprint, wayyyy more than I need but nice to have the extra capacity...lol

 

 

[slydog 7,875]

Id go for a GT35 as they come on boost instantly on a 250 anyway.Convert to a 4 barrel set up as your about to jam it full of air. A 2 barrel is too small on a 200 engine let alone a 250. Id measure compression first before lowering it and if it's around 10.1 leave it alone or your making it a laggy by lowering compression for no reason. I know you don't want to make a million hp but your actually treating it better if you let it become more efficient. Upside you don't need to push it as hard to get the results you want.   Id fit a programable ignition too. EST dizzy and ecu or maf control. Then you can run 28 plus degrees @ idle and low RPM no boost then drop timing as boost comes on. 

[Stumps 369]

Hmmm Interesting info Slydog.

 

I have looked at a 4bbl setup for the Pre Xflow, most of the info I have been looking at for carb blow through systems recommended a carb on the slightly smaller size compared to a draw through system that needs quite a bit of CFM. I'm bit miffed on what is correct, I'd imagine that going for an Aussiespeed 4bbl manifold and the sniper 4100 4 bbl efi system would be the safest option as the EFI is only going to use what it needs and wont "over carb" the engine. 

 

The compression is a bit mystery side of things, no real markings on the pistons other than indicating that they are 0.030 over, but they are dished. the Head itself looks like it might of had a small amount of material removed from the surface, the combustion chamber look huge and factory like. I'd imaging the compression to be between the factory 9.5:1 and 10:1. 

 

Will these compression ratio's be safe with the older pre xflow head? I am planning on running boost control either with a 6AL2 or ICE setup.

 

The exhaust manifold is a little bit of a mystery to me, I'm not sure who I could get in wagga to make up one from scratch for me, but I was planning on using an Aussiespeed or similar dual outlet manifold to a J pipe and positioning the turbo near where the battery currently sits, the futura doesn't have aircon so no compressor in the way.

 

I had a look at the factory 1v manifold but it seems to be incompatible with the 2v head, it would of been the easiest option for a manifold had it fitted.

 

I'm sure I'm over thinking most of this, surely blowing a pre xflow couldnt be all  that much different to a crossy.

 

please feel free to correct me if i'm wrong on this.

 

 

[Stumps 369]