Type 4 turbo: 2,2 ltr: New cooling system

[r_towle]

not doubting...just reading.
I went a got a book called "maximum boost"...
You have inspired me to learn...its just to much free power...

Rich

[Wally]

Just got my new turbo in

[jonas_linder]

Now it will be interesting to see the back pressure again

[34plus2]

walter,
what about headersize? where is the limit of the header in your opinion?
steven

[Wally]

Now it will be interesting to see the back pressure again

Yes, that should be sort of 'ideal' when this thing runs
The excellent turbine aero of this particular turbo (its sort of an unique/custom combo) was one of the main reasons...

[Wally]

walter,
what about headersize? where is the limit of the header in your opinion?
steven

I will keep the current primary header size. I don't think you will find the first limit in there Steven. It sounds like you may still be thinking too much N/A here

[r_towle]

Wally,

What do you think about putting two smaller intercoolers (air to air) underneath the floor of the package tray. Install vents just behind the windows (like the old empi scoops) and build some duct work in the package tray to divert the air through two coolers about 1/2 the size of the one cooler you have. The intercoolers would be on either side of the transmission.

Routing the initial intake from the turbo through the intercoolers would be fairly straight forward...and a single tube up into the engine bay.

Rich

[Type 4 Unleashed]

walter,
what about headersize? where is the limit of the header in your opinion?
steven

I will keep the current primary header size. I don't think you will find the first limit in there Steven. It sounds like you may still be thinking too much N/A here

Having built around 300 manifolds in the last 14 months, and back to back tested on 7 cars to date, I hope I can help answer some questions. Mind you, not all are based on a mathematical basis or "perfect world" situation.

Firstly, unless your building an engine that is going to be pushing the limits of extreme hp for a given capacity, forget valve sizes, port flow, intake flow, rpm, and just about every highly technical question you WANT to ask about designing a turbo manifold.

The 3 things you need to know to design your manifold are the port outlet sizes in MM, Projected hp output/use, and room restraints. For anything that will make less than 4-5hp per cubic inch, your runners should never be bigger than the outlet size of the exhaust port. If you have an oval outlet, usually pick a diameter that is maybe 1-2mm taller height wise than the port, and when you build the manifold, weld along the top and bottom, then heat with an oxy and stretch the pipe out each side to match the oval shape of the port.

Gas velocity is critical in a turbo manifold. People think that small pipes will increase back pressure, but forget the pipes aren't the restriction, the turbine housing and turbine wheel are the restriction. In outright terms, the pipes, even when 10-20% smaller than the port represent less than 5% of the total system back pressure. HOWEVER, the faster and harder the air travels through the turbo, the less back pressure the SAME turbocharger will impart on the system back pressure, and this is free hp.

The second critical parameter in turbo manifold design is the collector. While I don't want to alert the world to how to do everything, seeing as how my whole career centers around my merge collectors and manifolds, the biggest gains we have seen over anything we have tested is purely collector design. There isn't a single manifold I have ever replaced or back to back tested against that hasn't either made more power, or spooled earlier than what it has replaced. No read that again. Not all manifolds have made more PEAK power (none have ever made even 1hp less), but if they DON'T make more peak power, they always spool earlier and make more midrange. You could offset this and run a larger turbine housing, and increase the hp here.

We have seen as much as 38rwhp on 4 psi less boost with some cars, and on a 4G63 race engine 380rpm faster spool. The car even made another 350lb more tractive effort. Seeing as how most people here are V8 and 4 cylinder guys, it’s a pinch of piss to make your own merge collector. Just get 2 pieces of pipe, cut the exact same bevel off each one, and then weld them together. Do the same with another 2 pipes, so you now have 2 pairs of V shaped pipes. You want to take half of the outlet diameter off the pipe, so when you weld the 2 halves back together, you get a circle again. Then cut/grind the same bevel off these 2 pairs of V's so that they can lie against each other just like the first 2 did. There you have it, your very own merge collector. IF you have a Milling machine this process will be far easier. I still find it easier to do the first pair of V pipes with a drop saw and just use the mill do machine these welded together. If you have a V8, you will need 2 sets of these obviously.

In designing your turbo manifolds, first stop, work out pipe diameter, next step, material type(I ONLY use steam pipe, stainless is far too prone to cracking, but that’s an article in itself), the turbo's, and lastly sitting it all in the engine bay. Start by tacking your merge collector to your turbo flange, this will make sure you allow room for it in your design. Next step, bolt the flange and collector to the turbo. Then with a mate or an engine crane, hold the turbocharger in position in the engine bay. Once you have it spot on, use some 10mm rod and cut it to length so that you can weld a brace from the head plate on the engine to the turbo flange. This way, if you pull it out of the car, you now can build it on the bench, just unbolt the turbo off it, and these are your start and finish point, just join the dots.

On the subject of pipe length, throw it all out the window, just build what fits with the least amount of bends and awkward shapes/pipes. If you can build them close to equal length while not adding ANY extra unneeded bends then do so, but don't compromise the design of a runner for the sake of length, every bend adds back pressure, especially with heavily expanding hot exhaust gas. Every time you go to add another stupid bend, ask yourself if you'd do it on the intake side?? No, I doubt it. I've seen some crazy manifolds in my time, and the crazy lengths people go to get equal lengths would be SOOOOOO outweighed by the 50 extra bends they used it would without a doubt make less power.

Lastly, on short versus long, again, build what fits. Here is a simple thing to keep in mind. If short pipes spool earlier and the turbo in the restriction, why not run short pipes, and a larger turbo?? Or next size up turbine housing?? You will lose that extra spool yes, and if the longer pipe WOULD have made more power, it now won't with the larger turbo on the shorter pipe, and I'll bet you 100% of the time that the shorter pipe will be easier to fit and save you a whole lot of swearing, blood, sweat and tears, not to mention difficulty in fitting and removing the manifold itself of surrounding accessories.

6BOOST

[Wally]

Wow! Where did that all came from suddenly?

Must say, I like what I read, it is well argumented and concurs mostly with my own (very limited) findings.

Thanks for that Richard! never knew you had such experience in that field

[Wally]

Wally,

What do you think about putting two smaller intercoolers (air to air) underneath the floor of the package tray. Install vents just behind the windows (like the old empi scoops) and build some duct work in the package tray to divert the air through two coolers about 1/2 the size of the one cooler you have. The intercoolers would be on either side of the transmission.

Routing the initial intake from the turbo through the intercoolers would be fairly straight forward...and a single tube up into the engine bay.

Rich

I think that would work just fine
Just read that the owner of 9ff Porsches was going to replace his water-air chargecoolers by air-air intercoolers because they - wait for it.... - were more efficient in his 1200hp project car

[Piledriver]

Wow! Where did that all came from suddenly?

Must say, I like what I read, it is well argumented and concurs mostly with my own (very limited) findings.

Thanks for that Richard! never knew you had such experience in that field

Please don't tease Richard for not quoting it right.
(a source/link for the quote would be great though)

Looks like great advice, esp interesting is the mention of using steampipe as a material and why...
IIRC SS cracking is also why Racer Chris make his works of art in mild steel.

[Piledriver]

Wally,

What do you think about putting two smaller intercoolers (air to air) underneath the floor of the package tray. Install vents just behind the windows (like the old empi scoops) and build some duct work in the package tray to divert the air through two coolers about 1/2 the size of the one cooler you have. The intercoolers would be on either side of the transmission.

Routing the initial intake from the turbo through the intercoolers would be fairly straight forward...and a single tube up into the engine bay.

Rich

I think that would work just fine
Just read that the owner of 9ff Porsches was going to replace his water-air chargecoolers by air-air intercoolers because they - wait for it.... - were more efficient in his 1200hp project car

The setup you are running Wally looks ~ ideal, a big whale tail out back can hold a nice big air/air cooler...
I wish that would work on a 914.

[Wally]

.., a big whale tail out back
.

Duck tail Pile...duck tail! get your animals straight!

but yeah, it worked even better than you'd believe. You can very well feel the difference in intercooler temp inlet and outlet left and right. Outlet side often even feels colder than ambient.
It is huge though and weighs...as its also 3 inches thick, but the extra power makes up for it I think.

[r_towle]

So,
the snow has melted and the fun season is starting.
I hope you had loads of fun skating this winter, but tell us about the new turbo please.

How are things looking on your motor?

Rich

[Wally]

So,
the snow has melted and the fun season is starting.
I hope you had loads of fun skating this winter, but tell us about the new turbo please.

How are things looking on your motor?

Rich

Ah, yes, I may have been lacking on updates in this thread..

I converted the BAS header from 4 into 1 to 4-2-2 for twin-scroll use.






Wastegate exhaust on the left:


After fixing some boost leaks, a loose divider wall and exchanging the turbine 1.00 A/R housing for a 0.91 one, I have 1 bar boost only some 500 rpm later then with the 30R, which is great I think considering how much larger this turbo is.
Also very noticeble is the much lower EGT (50-75Celcius less) which is indicating much lower back pressures, probably more in the 1-1 ratio. That fact makes me more confident to run a bit higher boost pressures.

Dynorun was done some weeks ago, but one of the fuel pumps crapped out slowly giving AFR's of 1.0-1.1 at around 400hp, 19 psi and 6600 rpm on the dyno and almost cost me my engine. In fact its amazing its still alive anyways with going that lean at that power level. The spark just didn't ignite the too lean mixture anymore and that stopped the run...

This was the first run at 15 psi wastegate spring:
http://www.youtube.com/watch?v=9TOIdkF6mbg



Anyways, new feed pump and upping the fuel pressure to about 55 psi base pressure helped to stay within parameters and I think we're good to go again.
Coming sunday there's a 1/8 drag race in street trim (street tires, interieur) so it will be good to run her again.
Maybe new dyno in april sometime.