Matts Budget 1.9 150 SRI

[matthewp1633]

So my manifold is ready to be fitted and I have sold my old set up to finance the next move in regards to the GTB2260. I was chatting to a chap who is big into the Audi tuning scene and he mentioned the use of an external wastegate as well as the VNT to over come the excessive exhaust manifold pressure that can limit power.

I have done some interesting research on the subject and the general thinking is that exhaust manifold pressure needs to be about one and a half times higher than the inlet manifold pressure to give enough volume to drive the compressor but not so much as to obstruct exhaust flow and therefore velocity. The general idea is to get the balance right to obtain max power and a quicker spool time....

With this in mind I have welded the flange for the external wastegate onto the manifold and plan to fit the wastegate with a pipe to reintroduce the gas after the manifold. Clearly in an ideal world I need to measure the pressure in the exhaust manifold but I cannot work out how. I plan instead to use a boost controller to adjust the wastegate opening point and a washer system to adjust the amount of gas flow.

I seem to remember Nutron doing something similar?

[matthewp1633]

vectra rear end inc defuser.jpg

So the fun begins!

I removed the Rad pack which is already without the AC condenser and pump. I removed the standard Fans and fitted a thinner fan so it can sit between the Radiator and Intercooler.

bigger new intercooler.jpg

I made some brackets to hold the bigger intercooler behind the crash bar. The New intercooler is an Ebay universal 220x55x63 with exactly 180mm hanging below the crash bar so it remains inside the bumper and isn t too low.

I have flipped the intercooler upside down so the inlet and outlet are at the top. This will allow shorter runs from the Turbo to intercooler and from the intercooler to inlet manifold. All the piping will be 57mm and I plan to remove the Anti shudder valve on the inlet manifold and remove some alloy on that point as standard its 47mm and I will bring it out to 57mm.

As the gas moving through the pipes is moving at the speed of sound at some points I don t expect power gains, I am just trying to put less stress on the Turbo. I might gain a little in regards to spool time but time will tell?

[matthewp1633]

The Manifold is nearly ready but I need to add the Wastegate port and outlet to the Turbo itself.
manifold and wastegate.jpg

I am also making my own downpipe but obviously Everything needs to line up so lots of test fitting over the next few days...
downpipe.jpg

[matthewp1633]

So the manifold is nearly done all I need to add now is the port for the wastegate.
new log manifold.jpg

I have put the turbo outlet in the middle of the manifold as I think the balance will be better in regards to exhaust flow. I struggled to obtain a 2260vklr turbo so I got a Billet compressor wheel and my colleagues at work (who teach engineering) machined the cover.

new log manifold with turbo.jpg

In the short term this set up should be a good way forward whilst I search for the 2260vklr.

[matthewp1633]

So with the manifold and turbo test fitted I started to think about the design of an exhaust down pipe. Another advantage with having the Turbo sitting in the middle of the manifold was that the down pipe design should be easier.
downpipe fun.jpg

As you can see from the picture I should be able to come out of the hot side into a right angle and then down. I plan to cut the standard pipe just in front of the flexi. Then one 90 degree bend can attach to another, run through the sump gap and then join the standard pipe see rubbish pic:
exhaust design.jpg

The whole custom down pipe should cost about £40 with the flange to the turbo £8 and the 2x 90 degree pipe £14. The down pipe will be 2.75 inch then stepping down to the normal pipe diameter.

I will have to add a bracket somewhere on the down pipe to give additional strength and brace the whole set up to keep stress away from the manifold.

I did have to make my own oil return pipe for the block which you can see in the back ground and now I know it fits I can remove it and clean up the weld and paint it

[matthewp1633]

With plenty of time on my hands (Thanks Corona) I began to give some more thought to the inlet side of things. With the new set up the run from the Turbo to the intercooler and then on to the inlet is about 50% shorter.

All of the pipes are 57mm diameter including the intercooler inlet-outlet but the anti shudder valve (often mistaken for a throttle body) is much smaller. There are also several obstructions in the inlet manifold that appear designed to help EGR mixing.

As my EGR is blanked and mapped out I plan to remove my inlet manifold and remove these obstructions. I would like to retain the anti shudder valve as I like the smooth shut down and I am fussy as my wife drives the car. I am aware that pushing down the clutch and turning the ignition off will probably give a smooth shut down but I like just turning the key off.
anti shudder valve.jpg

I guess one option is to remove the flap, trim out the hole to the required size and fit a larger flap.......

[northpole]

not only that but the ASV is your only help when the engine decides to run away... just turn the key/ starve the engine of air and it will stop running...forget about the wife, it's a safety device that can safe your engine in an emergency ... it's often overlooked so yes pleas try and keep it

[matthewp1633]

On inspection of the Anti shudder valve (ASV) there isn t enough meat to go grinding out the hole to make it bigger....

However with a little investigation I found some chaps race running the same engine in an Alfa Romeo 147. They had in fact made themselves a custom manifold which to be totally honest didn t look that great. However they are sure the custom manifold was a worthwhile effort and so that got me thinking again.....

The manifold on my Vectra shrinks to about 49mm as it passes through the ASV and remains that way until it goes past the manifold to ASV bolt flange and then it widens up again. The throat of the manifold also doesn t have enough meat to grind it out so this is a problem.

I figure I could cut off the bolt flange and Tig weld a nice 57mm pipe to provide a uniform diameter run all the way from the intercooler straight into the manifold. I still wish to retain the ASV function so I need to give that some thought!

[northpole]

find any type of ASV that has the desired 57mm than cut and weld a straight pipe to it... transfer the electric parts from your oem one over to the custom one... that should work... but it's just an idea mate i'm not sure if you it be done that simple but my mind says it should be that simple problem is though what car has one that is big enough?

[matthewp1633]

I am doing a bit of digging around to see if I can find one that is the right size for my purpose. My other fall back option is to transfer the flap and mechanism over to the inlet pipe of the turbo into a 57mm pipe. I did consider trying to manufacturer something for the boost side using the old ASV but that will be near impossible with with the planned 3 bar boost will cause problems with leaks no doubt.

On the Air inlet side of the turbo high boost won t be an issue.