200ci Turbo investigation

[a65mustang]

Hi all,

I'm early into an investigation for a turbo setup on my 200. This is definitely not something that I'm obsessed with doing but am curious and wanted everyone's thoughts. Feel free to be brutally honest.

Goals:
-Keep the set up as stock as possible, so think of this as being as close to bolt-on as possible.
-Not looking to race and don't want a car that can barely idle with some crazy cam, I'm only looking for modest increase in performance and responsiveness.
-Have stock 7.25 rearend, want to keep it so can't go crazy on HP
-I have a 2v, DUI and T5.
-Aiming for 8-10lbs of boost. Small, yes, but any increase in output will be noticable for the car.
-Don't want to ruin the engine and trying to keep as much stock as possible, including the small log intake and, if possible, stock exhaust. Yes, there are likely fitment issues, esp with the carb and stock hood.
-Part of my interest is simple curiosity and enjoyment.

I have zero experience with this so has anyone tried anything along these lines, esp the small log? I realize it seems like a huge commitment for approx 20-30 HP but I like to tinker. General thoughts? Ballpark cost?

Thx
B

 

[bmbm40]

Hi all,

I'm early into an investigation for a turbo setup on my 200. This is definitely not something that I'm obsessed with doing but am curious and wanted everyone's thoughts. Feel free to be brutally honest.

Goals:
-Keep the set up as stock as possible, so think of this as being as close to bolt-on as possible.
-Not looking to race and don't want a car that can barely idle with some crazy cam, I'm only looking for modest increase in performance and responsiveness.
-Have stock 7.25 rearend, want to keep it so can't go crazy on HP
-I have a 2v, DUI and T5.
-Aiming for 8-10lbs of boost. Small, yes, but any increase in output will be noticable for the car.
-Don't want to ruin the engine and trying to keep as much stock as possible, including the small log intake and, if possible, stock exhaust. Yes, there are likely fitment issues, esp with the carb and stock hood.
-Part of my interest is simple curiosity and enjoyment.

I have zero experience with this so has anyone tried anything along these lines, esp the small log? I realize it seems like a huge commitment for approx 20-30 HP but I like to tinker. General thoughts? Ballpark cost?

Thx
B

A few years ago I read a post talking about a turbo set at lower boost for the reasons you stated but don't remember if it was a planned project or in process. Seems like a good idea to me plus turbos sound kind of cool and if you have fabrication skills you can keep costs down some.

 

[powerband]

Go for it. 'tinker !,
.
Forced Induction 'bolt-ons' were widely available at one time and with 'modern' available ignition controls, fuel systems and AFR monitoring etc , performance gains vs NA are comparatively inexpensive ... :
.
. .
.
the success Buick had with the pushrod V6 GN series 231 cid turbo car was preceded with the same pushrod V6 with Draw-Thru carbureted turbo cars from the BOP part of the GM . The carbureted' late 70's early 80's USA - "BOP" Draw-Thru forced induction 231 CID V6's (later Grand Nat'l) used a specially built Thermo-Quadrajet with External Power Valve boost reference . The carb on a Draw-Thru setup has no pressurization of carb bowl so the mechanical pump without bypass return or boost referenced fuel pressure is all that is needed.
.
Complete Buick Draw Thru Carb/Plenum/Turbo on simple adapter for the carb port and "J' exh. pipe .
. . . . .
.. setup lasted until @ 15 PSI of boost at which piston ring lands cracked off leading to sudden loss of power and cloud of oily mist across windshield ...

8-10 lbs boost on stock engine is optimistic but if NA compression ratio kept under @ 9:1 - ARP fasteners for cyl head and sufficient attention is given to ignition advance limit/control and air-fuel ratio under boost, with a tight engine you can build a drivable and reliable setup. As you research you will find the the devils' in details with needed modifications for boost ...
.
at @ 9:1 static compression ratio ,the compression ratio at 10 lbs boost is over 15:1 !
.

.
my current inline 250 six with stock internals has a Blow-Thru setup (SC) using widely available and easily mod'd (Hangar18') Holley 2300 series 2Bbl . Elec fuel pump, Boost ref'd regulator with return to tank required, and careful Ignition Timing and AFR monitoring has provided thousands of miles of fun.
.

. . .
.

have boosted fun

 

[Otto]

Don't know if this answers your questions or just creates more of them, but I tried what you're talking about around 30 years ago and threw this together:


Simply fabricated before the internet days with an AirResearch TO4b turbo and some odds and ends from a Kenne Belle Buick V6 kit. This fit within an early Mustang engine compartment and made around 8-10 pounds of boost. It tended to ping when making that boost and I struggled with getting the automatic transmission to shift correctly when making the whoosh sounds. It wasn't on that car very long but I've kept it all these years thinking it might work better on a vehicle with a manual trans.

I've considered this on my early Econoline, but not sure if it would fit in the tiny engine box. So it can be done minimally, likely much better these days with all the internet knowledge.

 

[alwill923]

From your starter thread, I am assuming the engine is in the car, together and stock.

• If so 8 to 10 lbs of boost is a problem. If engine is stock the compression is ~8.5. Using the chart gives 13.1 to 14.3 SCR. Gas octane will be a problem causing pinging. Stock cam timing will not work. Calculate the DCR with a stock cam and those SCR's, No good. You will need a very high performance cam with a very late intake closing, which will mean bad street manners, no low end torque, terrible gas mileage and high octane gas.
• Pistons should be forged for any kind of boost; however at low boost pressures you may be able to use stock pistons for a while.
• Ring gap must be increased for boosted applications.
• Cooling becomes a problem. Radiator size, fans etc.
• Distributer must be designed for boosted operation so timing is reduced under boost.
• Install ARP rod bolts.

Your best bet would be to build another engine for boost. If this is not the case limit the boost to say 5 psi. and choose the turbo wisely.

 

[a65mustang]

Thanks all, this is all very helpful. I'm fine with targeting 5 lbs as I'm just looking for a small step in HP. When you say choose turbo wisely, do mean quality or size? In terms of quality, any brands you recommend, better yet any to avoid?

Engine is in the car, and to my knowledge, is stock, but I haven't pulled head or dug into it beyond removing the oil pan and valve cover. Planning to pull it sooner than later so I will get a better sense of what I'm working with. I'll have the valve cover off this winter bc after the t5 swap/rear main seal replacement over the summer, I now have a lifter clicking. Hoping that after the down time, just needs to be run gently for a bit.

 

[alwill923]

I am not a turbo expert and do not have turbo experience. My suggestions are what is required by reading on the subject.
The size is very important. You need to know how to read turbo maps and match to the engine.
There should be more knowledgeable people here that should be able to help on picking the right turbo.
Call turbo manufacturers and get their help.

 

[aussie7mains]

Ive messed around with turbo and supercharged, IMO unless a turbo setup is really well integrated into the engine, a supercharger works better on the street. The down low boost of a blower makes the car much more fun to drive. To that end i would advocate you look into one of the smaller rootes type blowers from some of the japanese models. Toyota used a 1.4litre displacement blower (SC14) see ebay, on one of their small cars, this running at the correct speed will give you a small amount of boost your asking for. for a 3.3litre six it would need to run about a 2:1 step up ratio. If you keep under 10psi (IMO) you will be OK with stock stuff. I dont know of the quality of the USA factory pistons, but here they stand up to some boost OK. I run up to 15psi on mine and so far OK, on LPG. The plumbing etc probably wouldnt be any more difficult than a turbo. Food for thought!

 

[powerband]

one pic is worth ...
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six's from my motivation and innovation tinkerin' archive:
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. . .
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. . .
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... after too much right foot enthusiasm

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havin' fun

 

[aussie7mains]

And Ill add mine, And i dont know how the oil ring land was broken, there should be much pressure that far down the piston.

 

[awasson]

@a65mustang Welcome to the club. I’m glad I’m not the only one who’s looking at boost ideas. A bunch of the guys here already have blowers and turbos so there’s a lot of knowledge. I like @powerband’s idea. Go for it tinker! Eventually, I’m going to. I’ve got some other things planned first.

I’ve done a bunch of online research on turbo for the 200 and it seems “in the wild” there are plenty of people who have just strapped a 61mm - 64mm turbo on their 200 and ran it successfully with a bunch of power, when they were conservative and kept it limited to 10lbs of boost. The problem with those pioneers, is that they were never satisfied at 10lbs and it seems that 15lbs is the line where, when they stray above it, they blow something up. I think if they kept it at 10lbs max, they’d have some lasting fun.

I don’t know how long you can run around with 7-10 lbs of boost on a stock engine. The problem is that with heat and pressure, you can close the gap on your rings and then blow the land off the top of the piston. I know exactly what the gap is on each of my pistons (.016” - .017”) and that’s fine for naturally aspirated. It might even be fine for modest boost but I think I will pull them and gap the rings at .023” so that they can deal with the added boost. That size gap is just an estimate based on some ring manufacturers gapping spec’s for high performance use. I remember a guy in an otherwise stock Honda civic with a 15lb boost turbo who took off down the highway like a shot. I gave him a ride to the next town when I came across him a few miles down the road. True story, he blew holes in his pistons. That said, I think we’re safe at 10lbs as long as the rings have enough gap and of course you are not running high compression.

I’m interested in info on what camshaft profiles are preferable for boost. I’ve read a few forum posts about camshafts and boost that got into the nitty gritty and suggest very specific grinds, “otherwise it’s just not going to work” BUT again, in the wild, there are guys who just strapped a turbo on and made it work. I’ve seen them with the Clay Smith camshaft I have and with other performance cams or stock cams and they seem to work for the purposes of their owners.

I think @powerband is right. Time to tinker.