What other mods can i do...?

Post by **PrecisionBoost** » Sun Dec 11, 2005 3:43 am

And no..... the GT28RS is the perfect turbo for our engine.... I've plotted the curve on several different boost levels.

It usually doesn't come with a T3 flange but some companies are starting to change over the T28 flanged housing to an identical one with the T3.

The GT28RS is good from 5psi to 20psi based upon calculations.

The factory 2.0L 8V came with a T25 turbo.....which was set for 7psi from the factory...... and a very common upgrade to make more than 12psi was to upgrade to a T28.

The stock T25 started to run out of steam around 12psi..... given this is on an 8V motor.... the T25 would probably be a litte small for our 16V engines.

Tom had a T25/T28 Hybrid in his car.

So.... the T28 is a good turbo.....and the GT28RS is even better since it spools up faster and has way better efficency.

kinkyllama · Post by **kinkyllama** » Sun Dec 11, 2005 3:55 am

Erfinder@PrecisionBoost wrote:And no..... the GT28RS is the perfect turbo for our engine.... I've plotted the curve on several different boost levels.

It usually doesn't come with a T3 flange but some companies are starting to change over the T28 flanged housing to an identical one with the T3.

The GT28RS is good from 5psi to 20psi based upon calculations.

The factory 2.0L 8V came with a T25 turbo.....which was set for 7psi from the factory...... and a very common upgrade to make more than 12psi was to upgrade to a T28.

The stock T25 started to run out of steam around 12psi..... given this is on an 8V motor.... the T25 would probably be a litte small for our 16V engines.

Tom had a T25/T28 Hybrid in his car.

So.... the T28 is a good turbo.....and the GT28RS is even better since it spools up faster and has way better efficency.

I quickly did a search to see what the stats on it were and the first thing that came up they were charging 1,080usd

Post by **PrecisionBoost** » Sun Dec 11, 2005 5:25 am

Ya..... but SSAUTOCHROME has bunch of them cheap right now.... but they are the regular T28 flange so they won't fit on our cast iron turbo manifolds which have a T3 flange.

I was very seriously thinking about making a T3 to T28 adapter flange.... I couldn't seem to find one online anywhere.

The T25/T28 flange is smaller than the T3 flange and there is a significant difference in the opening area to the turbine.

Given the manifolds are cast iron it would be hard to cut the T3 flange off and weld on a T28...... odds are very good that cracks would form within a few months.

Post by **PrecisionBoost** » Sun Dec 11, 2005 5:33 am

Hmmm.... while thinking about how to make a T3 to T28 adapter I came up with a good idea for a T3 spacer to make my turbo fit.

I thought about this originally but I came up with a slightly different idea.

Right now my huge ass T4 compressor housing is hitting the block.... so I was going to make a spacer to push the manifold out 3/8"

I bought the material.... but I can't seem to machine it perfectly flat.... it's really bugging me.

So instead.... perhaps I will make an angle T3 spacer which will push the turbo away from the block enough to make it fit good.

Originally I didn't think this would work.... but I think I came up with a slightly different design that should work.....the original angled flange was going to be 1/2" thick... but the bolts wouldn't seat right..... they would be at an angle.

Instead.... I'm going to make it 1.5" thick and have two different sets of unconnected bolts.... one set goes in 1/2" straight from the back side of the manifold and the other set are 1/2" deep and are angled and bolted to the turbo.

So.... instead of one set of bolts and nuts that go through the manifold spacer and turbo.... I will use two different sets of bolts with no nuts.

Too bad the place I get steel from is closed tommorow.... otherwise I'd start on it tommorow.

Oh well..... I guess I should finish my renovations here at my new house.

Audacity Racing · Post by **Audacity Racing** » Sun Dec 11, 2005 5:55 am

chris... unless you are gonna cnc the channel out... i have no pity for you and the vast amount of time it's gonna take ot mill the hole through it

kinkyllama · Post by **kinkyllama** » Sun Dec 11, 2005 9:20 pm

ssautochrome is where i got my turbo from.

Thats a huge spacer

Post by **PrecisionBoost** » Mon Dec 12, 2005 12:54 am

Audacityracing wrote:chris... unless you are gonna cnc the channel out... i have no pity for you and the vast amount of time it's gonna take ot mill the hole through it

I have a milling machine..... it will probably take me an hour or so if it's made out of stainless.... which is a small price to pay.

I've allready got about 3 hours into the manifold spacer...... I can't seem to get a perfectly flat surface milled..... I think I need to get it ground instead of machined.

I'm using a 2.5" milling head and I've been clamping it down like I should.... but I'm finding thickness changes in the 0.010" range.... which isn't a whole lot.... but I can feel the ridges.

I wish I had set up the clamps slightly differently ...... it would have allowed me to make a more consistant cut..... with the long length I have to reposition the piece twice to get the entire surface milled.... which is why I'm getting these ridges between the first cut and second cut.

I'm surprised at how much this 1/2" thick piece of metal flexes when pressure is put in different spots.

I'm not used to milling such a long piece of steel..... most of the stuff I do is small.... typically only a few inches by a few inches..... so I'm not that familiar with the "correct" way to secure such a big piece of metal.

Audacity Racing · Post by **Audacity Racing** » Mon Dec 12, 2005 1:00 am

how big exactly... post up a few dimensions and i'll help you (my minor for materials science is manufacturing and industrial technology

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