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advice T72 turbo setup

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Old 12-04-10, 04:01 PM
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advice T72 turbo setup

I just purchased a T72 turbo from cxracing. Now I need some advice on a wastegate and a BOV.

This is the turbo. http://www.rotary-works.com/mm5/merc...gory_Code=TRBA

I also just bought an AEM Uego wideband 30-4100 because lots of people on this forum use them, and I don't need another ECU-like computer box in my car. This gauge has the electronics built in to the gauge housing.

Full 3" exhaust with an RB universal "large" presilencer and universal muffler.

Currently has 550 primary and 550 secondary injectors but will go with 1600 secondaries after engine break-in and ready to venture into boost.

Currently single Walbro 255. Should I grab another and run them parallel?

So now let's discuss wastegates and blow off valves. A wastegate is necessary but apparently a BOV is not?

I was told I'll need a 60mm wastegate and plan on making 500HP. StevenSimon went with a 46mm on his stock ported 20B. Mine is streetported. I figure I should go with 60mm/46mm to be on the safe side. That is to say one with 60mm and 46mm holes. Probably no need for a true (expensive) 60mm in/out wastegate like a Tial or HKS, right?

Point me to a cheap 60mm wastegate and make my day happy. Like this http://cgi.ebay.com/ebaymotors/60MM-...item5196853bbb
Old 12-05-10, 04:48 PM
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Anyone used a wastegate like this before?

Old 12-06-10, 12:10 AM
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Prefer genuine Tial MVR 44 or synapse. Stock up on big springs. Spring >>>>> EBC

Also prefer bigger turbine housing than 0.96. Been told there is a 1.14 or 1.16 single entry T4 out there to suit P-trims. Even that is a bit small for a ported 20B imo.

I would be looking at Q-trim turbine and 1.1 or larger turbine housing.

One of my mates uses a Q-trim 1.15 on a 12A.
Old 12-06-10, 06:53 AM
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I agree on the larger turbine housing with a 20B. The .96 will likely limit top end power with the 20B. I'd certainly try what you have, since it's already in hand. It should be very responsive. If it does limit top end, it is easy to swap turbine housings. A little harder and more expensive to upgrade turbine wheels though.

As for wastegates, go with a brand name. The picture above looks like a Chinese knock-off. Spend the extra on a brand name like Tial. A wastegate is not something you want to save a few pennies on at the possible expense of a failure. I'd talk with your manifold builder about what would work best. Their design will dictate what will work.

Blow-off valves come down to personal preference many times. Search to find what holds boost well without leaking. Again, Tial and the name brands are known for quality. The cheap Chinese crap, no so much.
Old 12-06-10, 12:06 PM
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Sorry I should have mentioned it's a very early motor with the small castings and weaker shaft, but apparently it can work up to 500HP if you're careful, according to GtoRx7 and Carlos at CLR. So I chose the .96 for good response around 400HP at medium boost so it will live a while and be a hoot to drive.

Now that I know what I know, I probably shouldn't have ported it. Hopefully the turbo will give back what porting took away from the low end. Oh and it should help spool it quicker.
Old 12-06-10, 12:26 PM
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Thanks for the info about wastegates. I'm building the manifold myself. Actually I'm doing everything myself with just the forum and PercentSevenC here to help me, and he's going off to college next month.

I have little to no experience with turbos. All I've done is installed an S5 turbo on Percent's old school R5 13B with a Weber DCOE blow through in his 1st gen. He did all the research. I just did the work and learned as I went. But it's just a simple blow through setup with a stock turbo and manifold. Only so much you can learn on a setup like that. This 20B setup is the first time I'll build a tubular manifold + install a wastegate + install an intercooler + a BOV + some larger fuel injectors + tune for boost. Let me back up. This is the first time tuning EFI period. I'm not just getting my feet wet here, I'm jumping in head first.
Old 12-06-10, 04:52 PM
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Hey guys, what size name brand wastegate should I get? This Precision Turbo unit looks pretty sharp. Is this kind of the ballpark where I should be looking? http://cgi.ebay.com/ebaymotors/Preci...Q5fAccessories
Old 12-12-10, 03:43 PM
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The synchronic 50mm wastegate looks promising. http://cgi.ebay.com/ebaymotors/Synap...Q5fAccessories Cheaper than a 60mm Tial. Probably better built than a Precision Turbo 46mm, and larger. And do I really need 60mm for my setup? I'm thinking 50mm would be just fine for 400HP at like 10 to 13psi or whatever it turns out to be.

I'm not looking for maximum HP like some of you are. I'm only interested in 400HP because it's an early 20B with weaker castings and weaker shaft. That;s why I chose a turbo with a .96 A/R instead of something higher. I did port the engine back when it was going to be NA. Now I will use a quick spooling turbo to give back low end that porting took away. If it chokes off at above 7k-8k, that's fine. Stock factory balanced rot assy and Atkins apex seals with no oil mods (well, maybe a few). It's for a 1st gen. 400HP is all I need.

What fuel line size is required for 400HP? The car currently has a single walbro 255 and 5/16" send/return lines. I hope I don't have to change the send to 3/8".

My rails are stock with 5/16" niples. Secondary injectors are upsized to 1600cc. Primaries are stock 550cc. Can I keep my 5/16" send hardline? It's less work.
Old 12-12-10, 11:04 PM
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I'm using the 50mm right now and it's great... no complaints.
Old 12-12-10, 11:31 PM
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the synapse synchronics are probably the best i've seen at keeping boost levels down but they do take a bit of messing around with to get your desired results since they have so many port configurations.

but where other wastegates couldn't hold boost levels down the synapse you could basically kill almost all boost if you wanted to.

you always take a big risk using cheap wastegates, i've used them successfully but i prefer not to suggest them to other people regardless of that success.
Old 12-13-10, 12:07 AM
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My Synapse 50mm holds my boost down to 9psi fine...I'm going to **** with the port config and get it to hold 15 psi...ditching this stupid ebc.
Old 12-13-10, 01:12 PM
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i guess, the holset does spool fast enough that the EBC is kind of a moot point to getting quicker spool from holding the wastegate shut longer.
Old 12-13-10, 06:48 PM
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Wow, that's three positives for synchronic 50mm wastegates. I'll ask Santa for one.

Thanks guys!

Now what about Synchronic's blow off valve? http://cgi.ebay.com/ebaymotors/Synap...Q5fAccessories

It's a different design from the name brands out there like Blitz, HKS, Greddy etc. I've read some good and some bad about them, like they don't work that well, the multiple nipples are hard to hook up or figure out, they're big and bulky making installation challenging etc.

What do you guys think? Would I be better off with a simple Blitz Dual Drive BOV? I'd like something basically quiet without the stupid fast and furious whistle sound. lol
Old 12-14-10, 12:22 PM
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If I could do it again I wouldn't run a bov. If you look up a thread plenty of people have been pushing their cars without a bov with no problems.
Old 12-15-10, 12:55 PM
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My turbo doesn't have an anti surge housing so I felt a BOV was a good idea.

I just bought an HKS SSQV for a great deal on eBay. It's an actual name brand! It's a pull type like the synchronic. http://cgi.ebay.com/ebaymotors/ws/eB...m=130465951667

Do rotary owners still use HKS parts these days? Seems like a 90s reference.
Old 12-15-10, 09:06 PM
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And now I'm looking at intercoolers. There's bar and plate vs tube and fin. All different shapes and sizes ie 25 x 12 x 3. Then there's coupler fittings in 3" or 2.5"? Headache time...
Old 12-16-10, 01:19 PM
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Most people I know are running HKS. I have a Greddy Type S and hate it just because I'm tired of the high pitch pew sound between shifts -_-
Old 12-16-10, 01:40 PM
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Thanks! If the HKS I'm getting comes with a whistle inducing insert, it's coming out quickly. I hate that JDM F&F sound lol.

As for the intercooler, I've learned the tube and fin style might be the better choice for my setup because it's cheaper, lighter, lets more cooling air through and on to the radiator and oil cooler, which I think for my setup is critically important. Plus I won't be running high levels of boost.

Let this quote from Evil Aviator explain it:
The solid construction of bar & plate takes more pressure. The bar & plate weight is usually slightly more than a tube type, but that varies between manufacturers, as my very large Spearco bar & plate intercooler is lighter than my friend's medium-sized GReddy tube intercooler. More weight may not be desired in a weight-critical performance car, but it tends to have more heat sink effect, which means that it will heat soak from a standing start, but it will also cold soak on the straights which cools down the charge when accelerating. Less weight allows the intercooler to respond more rapidly to flow changes. The bar & plate has more core for a given overall intercooler dimension because it does not require headers. The tube type tends to be more aerodynamic. Both types have about the same cooling efficiency for a given core size.

In general, tube & fin is fine for a street car, and is usually less expensive than bar & plate. Most race cars, especially high-boost drag cars, usually use the bar & plate type.

If you don't like the bad-looking quality of bar & plate intercoolers, then stick with a good brand like Spearco. If you are only looking at cheap Chinese and Mexican intercoolers on Ebay, then you may want to use a tube type.
Old 12-16-10, 02:34 PM
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I'm using a bar and plate ebay (Godspeed) that's similar to the dimensions of the Greddy 3 row one for the FC. When it was tuned in the winter on the dyno with a BNR stage 3 and meth the cold side pipe was cold and the hotside pipe was warm, which was good. Now in the summer one side gets hot and the other warm..I think that's bound to happen in the summer considering the air outside is 90F+, but who knows..

If you're going tube and fin, definitely use some kind of water or alchy injection.
Old 12-16-10, 03:50 PM
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Really? I haven't looked into any aux injection yet. Not really interested in it for my power goals; seems unnecessary for 400 out of a 20B.

If bar and plate reduces my need for any kind of aux injection, I'll just go with bar and plate then.

One nice thing about the cx-racing (eBay) bar and plate intercoolers is they offer a choice of 2.5" or 3" coupler connections. I'm thinking since my turbo and intake elbow are 2.5", I should get the intercooler with 2.5" couplers. Just an FYI their tube and fin intercoolers only come with 3" connections.
Old 12-16-10, 10:30 PM
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I'd get aux injection regardless. Like if you get a rare shitty tank of gas aux inj can save you. Don't tune for it, just use it as a safeguard then. That's what I'm using it for.
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