Turbo or turbo pt

[phatdad]

I spoke with a very reputable Automotive company a while ago.I will not list company out of respect. The owner stated he new a engineer on the development team at Chysler. that these upgrades were now only on paper. That they may do something when demand for the car goes down,demand has gone down as many of u know there are many turbos on the lots . My personal feel as I stated on another post is when Chysler started warr. for 7-70 why bring out upgrades that will jeopardize that warranty. Most people who buy these upgrades will be beating the snot out of their PT. To me its seems like a diaster waiting to happen on a business standpoint. HOPEFULLY Iam wrong. As I stated before I hope the upgrades come out by the 29 of march so I can have some fun on the way home from TURBOVILLE !

[bstockum]

I am all for the new GT, .... believe it or not! I have suggested to many, that if they were not burried in their Cruiser, it would be very hard to beat the new one, as long as they were satisfied with what they test drive! .... cause DIY upgrades are going to be a while in coming, .... and longer for the factory ones!
If you are a new / perspective buyer, BY ALL MEANS!!
.......................... ** get a GT! ** ..........................

It is a great base to build from!

The rest of us that got the weak kneed Caravan engine, need to do some extra work to beef the bottom end up.

I am inside of both the GT and the regular 2.4 engines and there is N-O-T-H-I-N-G inside the GT engine that can't be fixed in the one you have!!

If you want to go fast in a PT, you would do better to buy/keep a 2001 and do a stage II deal like I have laid out and have very few cars to worry about.

Screw the warranty, ... for the most part! ... YES, ... THERE ARE TIMES WHEN IT PAYS, .... but I have never been luckey enough to take advantage of it!

I'm sure there are many that have. Yea, for you. ... I've never won the freekin lottery either.


Bob

[jrs2002 ronjon]

Bob where are you located whats the cost installed if you dont mind me asking for stage 1 and stage 2 Thanks again for sharing your time with us.Jerry.

[rockycruiser]

I am all for the new GT, .... believe it or not! I have suggested to many, that if they were not burried in their Cruiser, it would be very hard to beat the new one, as long as they were satisfied with what they test drive! .... cause DIY upgrades are going to be a while in coming, .... and longer for the factory ones!
If you are a new / perspective buyer, BY ALL MEANS!!
.......................... ** get a GT! ** ..........................

Always appreciate your insight, Bob. I think this question fits this thread--if I'm upgrading the exhaust system on the GT (and anticipate some power upgrades down the road), what would be your recommendation for the MINIMUM ID for a dual exhaust system?

Again, many thanks for contributing your expertise to the forum.

Stephen

[Cal Cruzer]

Not to mention factory warranty

[Crush]

JRS 2002 ron jon,

The guys in this thread have done all the homework for us. Saving for the turbo upgrade as we speak. I'm planning on putting Cragar S/S 17" with 245/40 17's all the way around. What model wheels and tire sizes are you running?

Suprised I haven't seen your sweet ride around Wellington. Homey! Keep a look out for the Gator Cruiser. Hope to meet you at a light or even better Moroso. Keep your eyes peeled.

[Mean Green]

Always appreciate your insight, Bob. I think this question fits this thread--if I'm upgrading the exhaust system on the GT (and anticipate some power upgrades down the road), what would be your recommendation for the MINIMUM ID for a dual exhaust system?

Again, many thanks for contributing your expertise to the forum.

Stephen [/b]

If you are going for the cosmetic look and for the sound go with duals. If you want performance then go for a single exhaust, preferably a flow through like the BTG at PT Tuning. Here it is from an expert.

Turbo cars and Exhaust pipe size explained, finally!

A very common question that always seems to come up during conversations about turbo charged automobiles is which exhaust system setup is best, now the mystery has been explained!

Here are the following excerpts are from Jay Kavanaugh, a turbosystems engineer at Garret, responding to a thread on http://www.impreza.net regarding exhaust design and exhaust theory:

“Howdy,

This thread was brought to my attention by a friend of mine in hopes of shedding some light on the issue of exhaust size selection for turbocharged vehicles. Most of the facts have been covered already. FWIW I'm a turbocharger development engineer for Garrett Engine Boosting Systems.

N/A cars: As most of you know, the design of turbo exhaust systems runs counter to exhaust design for n/a vehicles. N/A cars utilize exhaust velocity (not backpressure) in the collector to aid in scavenging other cylinders during the blowdown process. It just so happens that to get the appropriate velocity, you have to squeeze down the diameter of the discharge of the collector (aka the exhaust), which also induces backpressure. The backpressure is an undesirable byproduct of the desire to have a certain degree of exhaust velocity. Go too big, and you lose velocity and its associated beneficial scavenging effect. Too small and the backpressure skyrockets, more than offsetting any gain made by scavenging. There is a happy medium here.

For turbo cars, you throw all that out the window. You want the exhaust velocity to be high upstream of the turbine (i.e. in the header). You'll notice that primaries of turbo headers are smaller diameter than those of an n/a car of two-thirds the horsepower. The idea is to get the exhaust velocity up quickly, to get the turbo spooling as early as possible. Here, getting the boost up early is a much more effective way to torque than playing with tuned primary lengths and scavenging. The scavenging effects are small compared to what you'd get if you just got boost sooner instead. You have a turbo; you want boost. Just don't go so small on the header's primary diameter that you choke off the high end.

Downstream of the turbine (aka the turboback exhaust), you want the least backpressure possible. No ifs, ands, or buts. Stick a Hoover on the tailpipe if you can. The general rule of "larger is better" (to the point of diminishing returns) of turboback exhausts is valid. Here, the idea is to minimize the pressure downstream of the turbine in order to make the most effective use of the pressure that is being generated upstream of the turbine. Remember, a turbine operates via a pressure ratio. For a given turbine inlet pressure, you will get the highest pressure ratio across the turbine when you have the lowest possible discharge pressure. This means the turbine is able to do the most amount of work possible (i.e. drive the compressor and make boost) with the available inlet pressure.

Again, less pressure downstream of the turbine is goodness. This approach minimizes the time-to-boost (maximizes boost response) and will improve engine VE throughout the rev range.

As for 2.5" vs. 3.0", the "best" turboback exhaust depends on the amount of flow, or horsepower. At 250 hp, 2.5" is fine. Going to 3" at this power level won't get you much, if anything, other than a louder exhaust note. 300 hp and you're definitely suboptimal with 2.5". For 400-450 hp, even 3" is on the small side.”

"As for the geometry of the exhaust at the turbine discharge, the most optimal configuration would be a gradual increase in diameter from the turbine's exducer to the desired exhaust diameter-- via a straight conical diffuser of 7-12° included angle (to minimize flow separation and skin friction losses) mounted right at the turbine discharge. Many turbochargers found in diesels have this diffuser section cast right into the turbine housing. A hyperbolic increase in diameter (like a trumpet snorkus) is theoretically ideal but I've never seen one in use (and doubt it would be measurably superior to a straight diffuser). The wastegate flow would be via a completely divorced (separated from the main turbine discharge flow) dumptube. Due the realities of packaging, cost, and emissions compliance this config is rarely possible on street cars. You will, however, see this type of layout on dedicated race vehicles.

A large "bellmouth" config which combines the turbine discharge and wastegate flow (without a divider between the two) is certainly better than the compromised stock routing, but not as effective as the above.

If an integrated exhaust (non-divorced wastegate flow) is required, keep the wastegate flow separate from the main turbine discharge flow for ~12-18" before reintroducing it. This will minimize the impact on turbine efficiency-- the introduction of the wastegate flow disrupts the flow field of the main turbine discharge flow.

Necking the exhaust down to a suboptimal diameter is never a good idea, but if it is necessary, doing it further downstream is better than doing it close to the turbine discharge since it will minimize the exhaust's contribution to backpressure. Better yet: don't neck down the exhaust at all.

Also, the temperature of the exhaust coming out of a cat is higher than the inlet temperature, due to the exothermic oxidation of unburned hydrocarbons in the cat. So the total heat loss (and density increase) of the gases as it travels down the exhaust is not as prominent as it seems.

Another thing to keep in mind is that cylinder scavenging takes place where the flows from separate cylinders merge (i.e. in the collector). There is no such thing as cylinder scavenging downstream of the turbine, and hence, no reason to desire high exhaust velocity here. You will only introduce unwanted backpressure.

Other things you can do (in addition to choosing an appropriate diameter) to minimize exhaust backpressure in a turboback exhaust are: avoid crush-bent tubes (use mandrel bends); avoid tight-radius turns (keep it as straight as possible ); avoid step changes in diameter; avoid "cheated" radii (cuts that are non-perpendicular); use a high flow cat; use a straight-thru perforated core muffler ... etc.”

[JOEM]

Originally posted by phatdad
find the real time video on stockums web site . view it then come on back and update your post . The Hahn turbo creams the GT.

Is this the Hahn turbo in the stock engine blowing 8-9 psi or in the beefed-up engine with intercooler blowing 12 psi?

[Da Brain]

JOEM,
If you read Bob's previous thread "The PT you were riding in, in the video had a completly stock engine, a stage I HRC turbo kit, an intercooler added, running 8-9 psi boost. Both cars were automatics, both were in low and the GT got to jump first."
you have your answer.
Da Brain Soon to be a B Stockum convert! Right Bob?















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[taikuchin]

Originally posted by jrs2002 ronjon
I have a question If I add an aftermarket turbo to my pt will it be as fast as the stock gt turbo that I test drove I think im in love with the gt my pts only 9 months old trade in or get turbo?

Look at it this way: For less than $5k you can crap on the GT with the car you have. How much will it cost you to trade up? For me, it would have cost $10-12k to trade for a Gt & more to make it my own. A no brainer!