Scottie-GNZ

Once you drive a properly setup turbo, you can never go back to NA! Having said that 250hp is lot of HP for 2000lbs and Webers on a V engine is really cool. The rush of a turbo just cannot be beat. Yeah, yeah, I know, that's debatable .

Contact Turbo Specialties, 205-444-5011, tell what your goals are (realistic ones ...) and tell them you need someone done at a reasonable price.

Mike, I certainly do not have anything to add specific to your question, but I agree with Grumpy about HP claims. I do not believe HP claims unless someone has a dyno sheet or a time slip to back up the claim. Now, that is not to say that some of the claims of 700hp might not be true, but as Grumpy said, they are probably on borrowed time or have never seen competition. Too many of these rods are limited to cruises, parking lot burnouts or quick 2-sec bursts. You on the other hand plan on having sustained high RPMs in the upper gears where the engine is under the most load. Keep that factor in mind as you ponder your decision.

Stony, if the engine is running fine today, then do not change the "curve", just the numbers that make up the curve. The numbers in the curve start with the base number at idle and that number is derived from a matrix supplied by SDS and factors in the cylinder displacement and injector flow. Use the matrix to derive your new base number. However, be aware that it is just a guide and you usually end up with a different base number after tweaking. SO, do it first with the 440s, then understand the variance between what the matrix says and what you have and apply the same to the new number. E.g., if the matrix says 80 for the 440s and the car is running fine with 76, then you know to make the new starting point 5% less than what the matrix says. Remember, it is only a starting point and still needs tweaking. I do not want to make it too complex but if you want to retain the same fuel curve with the new base, then you need to understand the curve. The way I do it is to place all the values in a spreadsheet and understand the % difference for each value. Once you derive the new base, apply the %s to the new base and let the spreadsheet generate the new numbers. Simple, eh? I would venture a guess that you will not have to change the fuel values for boost (the MANPRESS map). Once you redo the curve for RPM FUEL, tune the car for normal running w/o boost first and once the car is running fine, then apply boost. Hope I did not muddy the waters.

I would turn it 90* clockwise to begin with, then put an immediate 90* bend on the top pipe. Open up the OEM hole on the drivers side of the radiator as big as you can get it, then run the top pipe to the TB and the bottom pipe to the turbo. Unfortunately that leaves the air filter in the engine compartment. Another option is positioning it so that the straight outlet faces down and the bent outlet faces the hole by the radiator and route the bottom pipe under the radiator support. Unless you are going for MEGA-HP, that pipe does not need to be bigger than 2.25". You can then route the TB pipe and a pipe for the filter through the radiator opening.

Arif, as you increase boost, you not only want to increase the fuel but you also want to retard the timing. There are 2 maps you need to focus on and if you do them right, you need to do nothing when you increase the boost. The maps are: MANPRESS - adds fuel based on manifold pressure. You build this map to add fuel as boost increases all the way to limit of the map sensor. If done correctly, when you go from say 10# to 15# boost, the added fuel required is already programmed in. IGN RET/MANPRESS - retards timing as boost increases. Same principle as MANPRESS but instead you retard the timing as boost increases. MANPRESS works in conjunction with RPM FUEL. Where RPM FUEL is your basic fuel map for normal driving, MANPRESS adds fuel only based on manifold pressure value. Do not increase RPM FUEL to compensate for boost. Well, you can, but you will have that increasedfuel all the time even when you do not need it . IGN RET/MANPRESS works in conjunction with IGN. IGN is your static and advance timing and IGN RET/MANPRESS comes into play when you hit a specific manifold pressure. The combination of the 2 is your total timing. E.g., if the value for IGN is 33* at 5000 RPMs and you running 12# boost and have a IGN RET value of 10* at 12# boost, then the total timing is 23*. HTH

Standard equipment in 911s or at least they were when I had my 79. Titanium alloy, sodium-filled to be exact and yes, they are PRICEY. Found out back in 89 when the timing chain jumped a couple of teeth at HARUMPHH RPMs and I bent all 6 exhaust valves . Back then they were $46/each. Broke all 6 rocker arms but did not even scratch the pistons. Still scratching my head on that one after all these years.

I am helping a buddy build a GN-powered 2nd-gen RX-7 and we just upgraded it to the 4-piston, aluminum calipers. Those are some impressive looking units and we have a spare set. Is this not one of the options we have for swapping onto the 1st-gen Zs? Anyone know the scoop on this swap, particularly the biggest rotor that could be used with it? The Vette rear rotor is 11.4" so something close to that would be nice.

U GOT SKILLZ!! Do you have an illustration of the end product or do we have to wait it out?

I assume you are referring to the difference between the 86-87 intercooled GN and the 85 and earlier. The basic engine is the same, but the prmary difference is that the early ones are referred to as "Hot Airs", meaning they are not intercooled. There is only so much HP a stock engine/turbo can make efficiently w/o an I/C

I will ask the Buick boards. Gimme a day.

If I interpret the chart correctly, 4BQ is a 84 Buick Turbo application.

http://members.aol.com/powerrslid/thm2004r.html

Kenny, the answer to your question is yes, but it does not make sense to do it if the air/air I/C does not have adequate flow capacity to begin with. Since water has a specific heat value 4 times that of air, the A-W core does not have to be as large but it must still have adequate flow. A complet A-W system would also have a small radiator mounted in the airstream to dissipate the heat absorbed by the water from the I/C and of course, a pump to circulate the water. Drag racers then add another component that would flow the water through ice before it gets back to the core or have the tank surrounding the core wide enough to be packed with ice. Obviously it is more complex and probably not advantageous for a regular street car.

The LT1 mini starter is a popular swap on turbo Buicks with the 200r4. Bolts right up.

I swapped one of the early Buick versions into a 73 vega GT and a MGB. That was a long time ago. With the 300ci iron head, you can get a decent power boost, but IMO, not enough to justify the lighter weight of the engine. The turbo version is not worth pursuing as it was a crude (by today's standard) setup with very low boost and if I recall, a 1-bbl carb. Yes, we can talk about the sweet British and Aussie versions, but the reality is that they are rare here and expensive. Try finding a Range Rover or TVR in a junkyard, then fainting after you hear the price of this "exotic import" engine . Not trying to talk you out of it, just expressing my thoughts. Yes, it is substantial lighter, but keep in mind that with an extreme setback placing the engine behind the front wheels, that weight gain becomes less critical. Also keep in mind that the rule of thumb is that 10lbs = 1hp and on the street, TORQUE RULES. It is easier and a lot cheaper to add 25hp to another engine. A stock L28ET with an I/C and exhaust will outperform the 215ci even after you have injected a lot of cash into it. If you still want to do it and pursue one of the import versions, be aware that some of them came with funky SU carbs.

Congrats!! Vince is right. Get the hybrid done pronto as I feel a minivan attack coming on

Terry, that is the only test I did as that was the only one I knew to do. The replacment is already installed and I will check for any leakage then go test it Wed night. One of the local Buick turbo shops supposedly has equipment specifically to test this, so I will drop by later this week.

I suspect I have a bad coil or coilpack. I was told to do a resistance test and a good coil should have between 11-13 ohms between the posts. I swapped mine out for a good one and all the coils on the good coilpack are indeed between 11-12. My 3 coils were 14.52, 14.88 & 15.05. So, there is a big difference in the resistance and mine is not in the "good" range, but what does it all mean and what about my numbers would make mine "bad"? Please educumate me . BTW, when I ran the car, it just did not feel strong and 2 plugs were very wet and both were on the coil with the lowest number.

Adam, at the moment I do not make a DP for the ZXT. To do it right, I would need a car for a couple of days to study it, do mockups, then work with the machine shop to make it. I never had a car or enough people showing interest at the same time to make me want to do it. Anyone else who designs and makes parts from scratch will tell you that you do not want to have to pay to do just one, but somehow those up-front expenses have to be covered.

Excellent! We just talked about this last night.

Jeff, any chance of scanning the article and making it available to all?

IMO, do the SVOs now. Remember that with the addition of the NPR and free-flowing exhaust, you are going to be making a LOT more HP running the same boost.

What kind of turbo did you get? Would be nice if it was not a stock replacement. You can make 300hp with the stock turbo but you will be pushng a lot of boost and be hard pressed doing it with the stock stock ECM and AFM unless you are really good at recalibrating the AFM. Unless you get a programmable system, you will need to redo the AFM and a programmable system would blow your $2K budget. To make 300hp reliably (I assume you mean RWHP), you need a hybrid turbo, upgraded injs, fuel pump, adj FPR, GOOD I/C and free-flowing exhaust, K&N-style filter forwad of the radiator, A/F mixture meter, a real boost gauge. An upgraded turbo could run as low as $450. You can go the used SVO 36# injs route for about $125 or find some used 420s for about $250. The pump will run about $200 new or you can try one of the low-budget OEM pumps (Ford truck, I think) that some seem to be having success with. A used FPR should run about $40. If the I/C you have is equiv to an Eclipse unit, sorry, it will not do. Budget $400 for a good I/C and quality mandrel piping. Cannot stress enough how critical it is to not go cheap here. Mixture meter and a new O2 sensor will run about $65, boost guage (do not even think about using the stock gauge) is about $35 and a 3" mandrel exhaust should run about $300 with a decent muffler like the Super Turbo. Filter should run about $75 with piping. Should not cost you much, but plan on replacing EVERY vacuum hose under hood. So much of your cost is going to depend on how much you can do yourself.

I am not familiar enough with the Z32 chassis to tell you whether or not you would have a fitment problem with the steering rod and the oil pan/X-member. Those are typically the 2 areas where you have problems. I would say since the TT engine has the turbos slung low on the side of the engine, the steering rod might not be a problem and you have the option of a adding a u-joint to the the rod, in case. Hopefully you can get the GN engine setback enough that the x-member would not be a problem. Because of the DOHC design, the TT is a very WIDE engine on top so there should be no clearance problems, but you need to consider room for the DP which will run about level with the plugs, to swing down at the back of the engine. Do not know the exact weight of the TT engine, but I would guess the weights, fully dressed, would be about even. A fully dressed GN engine weighs in at a little over 400lbs and remember that a TT engine has double everything. Performance wise, a stock GN engine is rated at 247hp compared by the 300hp for the TT. Do not be fooled by those numbers as the GN is a torque monster and since you are going to have to do a custom DP and I/C anyway, just adding a more aggressive chip ($25-50), K&N ($60) and a couple more psi of boost ($2.50), you are now well over 300hp with torque approaching 400 lb/ft. On the street, that is what counts, not hp at some ungodly RPM. Not sure what final drive you would have, but the GN engine runs best with about 3.50 or taller. When racing from a stop, 1st gear is a mad rush (my 1-2 shift happens in a tad less than 1 sec) so you do not want a tight 4.10 or even 3.90. That is something you can address later and there should be no concern about the strength of the IRS. I find the TT crowd a bit snobbish but since you are on this forum and considering a swap, you are obviously not a purist. $$-wise, expect to pay about $2500 for a GN drivetrain. The DP/exhaust and I/C should be a part of your swap budget. After that, you spend the aforementioned "BIG" bucks for the chip, filter and adj wastegate rod. I would also recommend spending $250 for the datalogger. Keep turning up the boost until you get detonation, then back off a notch. Compare that to have to marry JWT or Stillen. As for the WTF factor, a GN engine is certainly not eye-catching as a TT, but you can certainly dress it up. The fun will be looking into the eyes of a TT owner when you pop the hood after bloowing away his Stillen Stage 15 setup .