This was constructed in an effort to create a sequential "stop when you're going fast enough" type of mod list. This list is welcome to any comments that you feel should be altered (order) or changed.
- ADDITIONAL BOOST GAGE
The stock boost gage on the dash is unfortunately more decoration than use because of its woeful inaccuracy. Even if you're not considering running high boost (I.e. over 18psi) the gage gives total peace of mind that the boost is accurately shown. On Saudi Syclones which have no boost gage at all, this is essential. A suitable gage is 0-30psi from VDO and which mounts well into Lyle Simons' A-Pillar mounting (As shown in the picture).
If a single pod isn't enough and more than one gage is required Lo-Tek Engineering now produces A-pillar replacements that allow the mounting of two or three gages.
The pillar mounting facilitates the monitoring of other engine parameters such as oil temperature, transmission temperature, exhaust gas temperature, etc. with the gages in an easy to view position.
- MANUAL OVERIDE FOR INTERCOOLER PUMP
With a stock chip the intercooler pump does not switch on until the coolant has reached 215F by which time major heat soak has affected the intercooler. This basically means that under normal driving conditions with only occasional use of boost the truck drives like a non-intercooled vehicle. To manually switch on the pump a simple circuit is required. On the fire wall above the distributor are two relays. The one on the right controls the intercooler pump and the yellow wire triggers the pump. Join a length of wire to the yellow and feed it across the top and down to the right where the grommet feeds cables through the firewall. It's a tight fit so it'll be difficult. Link the wire to one pole of an on/off switch and link the other pole of the switch to ground. The pump should now run when the switch and ignition are both on.
- GOOD PLUGS
Various plugs have been tried but the stock AC CR42TS seem to give good reliable performance. (Note, be sure that you use the CR42TS only as these are a Quantum plug deigned for the Syclone/Typhoon application.) Other plugs that have been tried with success:
There have been reports of some problems with full platinum plugs so if in doubt stick with the stock plug type.
- NGK BPR6FS
- Autolite AP24 platinum tipped with copper core
- Accel 274 U-Grove
- 180 DEGREE THERMOSTAT
- AUXILIARY HEAT EXCHANGER
The stock Charge Air Cooler (CAC) system is barely adequate for the stock boost levels and the radiator for the CAC coolant is poorly located and not of a large enough size. ATR produce an auxiliary radiator which mounts in front of the engine coolant radiator. This increase in size provides additional cooling to significantly reduce intake temperatures. The stock CAC pump has a poor flow rate and low pressure making it unsuitable for use with a larger CAC radiator so the ATR kit comes with a new CAC pump which flows 10 times more than the stock one.
An alternative to purchasing the ATR kit is to make a similar one for a lot less: Order a Haydon Transmission Cooler, Model 1241 from Pep Boys or a similar outlet for around $110. Haydon can be contacted on 909-736-2665 for details of a local distributor. To install the cooler have a look at the auxillary intercooler installation instructions. The pump used by ATR is the Shurflo 2088-403-444 which is available for about $70. Call Campers Choice 1-800-833-6713 for part# A191 for a cheap deal, or Shurflo at 1-800-854-3218 for the name of a local distributor. An alternative is the Atwood Areator A500 pump, available from Walmart for around $30. To fit the A500, use the procedure detailed in the auxiliary CAC pump installation instructions. Fitting of the Shurflo 2088 requires additional mountings as it doesn't fit in the stock location.
- PERFORMANCE CHIP
Todd Austinson produces a 10-in-1 chip for the Syclone/Typhoon.
The 10-1 chip is a replacement computer chip that contains 10 programs on one chip and fits piggyback style with the stock memcal entirely inside the stock ecm. These chips will work great on any Syclone/Typhoon running the stock injectors, cam, and heads, and will enhance the performance of upgraded turbos, intercoolers, and other common bolt-on modifications. An external display/switch, about the size of a radar detector, is used to select the program, and displays the program currently selected. This unit also contains a lock, allowing you to lock the chip in its current setting. The performance programs are: two (2) 93 octane street versions, one with ~16 psi boost programmed, the other with ~17.5, a 93+ octane street/strip, a 93+ octane strip, both with ~17.5 psi boost programmed, and finally a 16 psi street program identical to the one above except for the idle speed set to 800 rpm. The convenience programs are: a valet program that significantly cuts power levels, security (no start), emissions, a program identical to the stock calibration with all limits intact, and another stock type program with the exception of the rpm and mph limits being raised, no boost limit, and 60 degree intercooler pump turn on temp. Boost levels will vary slightly from vehicle to vehicle depending on state of tune and modifications.
The 10-1's are ready for immediate delivery.
Some of the features of the 4 performance programs are:
- -Boost controlled by chip at selectable levels of 14.5, 16.5, and 17.5 psi
- -Faster turbo spool-up
- -Smoother idle
- -Intercooler pump turn-on temp lowered to 60 degrees F from 180
- -Max allowable knock retard raised 3 degrees for safer operation
- -First time boost disable eliminated making staging easier at the track.
- -Rpm limit raised to 5300
- -Mph and boost limits eliminated
- -EGR disabled on all the street, street/strip, and strip programs.
The 93+ octane street/strip and strip programs require more than 93 octane to run safely on a stock vehicle. Each vehicle’s state of modification and ambient conditions will determine what octane level is required. My Typhoon, for example, with upgraded turbo and intercooler can run the street/strip program at 17.5 psi of boost with no detonation on 93 octane fuel. This is due to the charge air temperature being lower from the turbo and IC over the stock units. I need about 95 octane to run the strip program safely at 17.5 psi boost. Knock retard and O2 volts or EGT temps should be monitored when using these programs initially to determine safe boost levels and octane requirements. This should be done when using any aftermarket program for the first time.
There are hundreds in use presently with performance gains averaging between 3-5 tenths in the quarter mile. Even more impressive results can be obtained at higher boost levels, but an external boost controller is needed to obtain more than 17.5 psi. I have run 21 psi using this chip and an aftermarket boost controller and gained .8 seconds over stock levels.
Price is $250 for the 10-1 including the display and shipping. If you would like to order one contact me by sending an e-mail with the subject line "Performace chip order" to Ty1548@aol.com and I will give you the payment options. You can also call me at (216) 433-6684 between 9:00-4:00pm EST.
- LOW RESTRICTION FILTER
The stock air element is the usual paper type and to increase airflow the addition of a K&N filter element (Part No. ??????) or equivalent low restriction filter will help. If guaranteed flow is required, removing the stock air box is better and a K&N 8" barrel filter (Part No. ??????) can be attached to the duct pipe. Note: Any change of filter to a less restrictive type will make the close throttle turbo boost noise louder (See the Engine Tour page for details)
- TURBO TO INTERCOOLER HOSE
The stock turbo to intercooler hose has a tight bend and its ribbed construction causes turbulence in the airflow. Replacing the hose with a section of radiator hose with a suitably smooth bend will help airflow. The original prototype Sy's have been seen with this kind of hose setup. Trac Auto has a radiator hose (Part #70689) that fits just fine with a little trimming or use the Goodyear part #60914.
A radiator hose from a GM truck, GM part number 15684449, has several 90 (or near 90) degree bends in it, and it's possible to make at least two (and maybe three) turbo to intercooler hoses out of it.
- FUEL PRESSURE REGULATOR
- HIGH VOLUME FUEL PUMP
- ANS BOOST CONTROLLER
To run boost levels higher than the stock 14psi an additional boost controller is required. The ANS boost controllers simple wiring, use of the stock wastegate solenoid and low cost (Around $200) has proved it to be the best choice for most applications. The lack of boost level feedback into the controller means that boost creep and over-boost can occur on some trucks (Depending on turbo wastegate condition, exhaust and other variables).
The turbo boost level is controlled via a little solenoid that sits on top of the turbo in the middle of a hose that runs from the turbo to the wastegate. The solenoid acts as a bleeder valve to create a small leak in that hose, so the wastegate won't see all of the boost pressure that the turbo is generating. That solenoid is normally open, so that if it fails, you will only get about 10 psi max boost [8 psi is where the wastegate starts to open]. When the truck is on, there is 12V running to that solenoid and a ground wire running back to the ECM which then switches the ground rapidly to pulse modulate the solenoid (i.e. open and close it really fast to leak-off the flow of boost pressure to the wastegate actuator).
The ECM monitors the boost via the Manifold Absolute Pressure (MAP) sensor. The ECM also has a table that indicates the desired max boost for a given RPM. When boost approaches max, the ECM will look in another table to see just how fast to modulate the solenoid. If the table indicates n-percent, the ECM will ground the solenoid wire n-percent of the time to cause it to close and leak-off n-percent of the boost pressure going to the wastegate. Spikes can occur if that n-percent isn't enough to open the wastegate far enough to control the boost.
The ANS controller is simply a device that will allow the driver to control that n-percent. The knob controls a 555 timer chip which is used to pulse-modulate the solenoid ground signal anywhere from open almost all the time (minimum boost) to switching so fast that it's almost closed all the time (More boost than you want to dream about).
Installing an ANS controller is quite easy. Since the plug that goes into the solenoid has 12V when the truck is on, that is where the power comes from. The stock solenoid plug is unlatched, the ANS plug inserted into to the solenoid, the stock plug is inserted into the socket on the ANS wiring and wire is bolted to a nearby ground source. The cable to the controller is run along the firewall, through a grommet then up to the dash facia.
There are two switches on the controller along with a boost level knob. One switch says "On" and "Off." In the Off position, the solenoid will not be modulated and only generates about 10 psi of boost - just the same as if the cable was unplugged on the solenoid. In the "On" position, the other switch comes into play. The other switch says "ECM" and "TC." The "ECM" will let the ECM control the boost as it normally does; it simply connects the ground wire that was on the solenoid back to the solenoid. The "TC" lets the knob control the solenoid's on/off rate. A small LED flashes to indicate the rate at which the solenoid is being pulsed.
It is VERY important to keep an eye on the boost. The knob on the controller cannot be set for 17 psi one day and have it always at 17 psi. Also, because the ECM does not have control of the boost level it cannot back-off the boost if it hears detonation
The ANS is a neat gizmo for the Sy/Ty: Its a plug-in controller with very little installation hassles; Unlike N2O it is relatively safe to use on a stock engine; It's a lot more convenient than a bleeder valve under the hood that you have to jump out of the vehicle and adjust each time.
- 108 OCTANE OR BLEND
If you're running race boost levels than there's no substitute or better engine protector than race fuel. Warning: Some octane boosters that are added to regular gas can damage the Oxygen (O2) Sensor. Make sure that if you do use a booster it is Oxygen Sensor safe.
- IMPROVED IGNITION SYSTEM
High boost conditions increase the risk of spark blow out and usually a reduction in spark plug gap is needed. To combat this and maintain economy, and off boost driveability the use of an addition CDI spark unit is recommended. The MSD6A has been used in conjunction with the stock coil by a number of truck owners. The Accel 300+ ignition module, which seems to work well by itself without the additional coil, but causes significant RF interference with an audible buzzing noise in the cab if the control unit is mounted to the firewall. Also, the increased voltage and current from the additional coil causes significant and accellerated wear on the rotor arm and the central contact post in the distributor cap. A prime example of where 'too much spark' is not a good thing. Accel Extreme 9000 plug wires, available from JEGS with part number 9034, fit well and are made for high heat applications. (which is good especially for plug number 6 and its close proximity to the downpipe.) Other custom fit wire suggestions are the Accel 8.8mm (8893) or the Taylor Spiro Pro (Summit catalogue No: TAY-74632). Any other high quality custom fit wires for the 1991 4.3L V6 will fit and work but care should be taken in ensuring the level of noise suppression is sufficient.
The electrodes on the 1991 and prior Delco distributor caps are an aluminum/zinc matrix. When they are subject to electricity and moisture there is a very reactive chemical reaction which leads to rapid corrosion and a reduction is spark transfer efficiency. Replacing the cap and rotor for a good quality equivalent like the Accel 8133 can sometimes cure misfire and engine stumble problems whilst ensuring the best spark delivery at all times.
- THROTTLE BODY AIR FOIL
Using a TB Air Foil in Corvette and similar naturally aspirated applications can yield up to 11 BHP extra. On a forced induction vehicle, however, the actual HP increase (If any) is unproven. The Engine Tour page shows the area which the TB airfoil connects to reduce turbulence when entering the manifolds.
- BRAKE SHOES
Good hold compound to allow more boost to be built.
- WHEEL CYLINDERS FROM S-10 MANUAL
Available from a 1991 or 1992 S10 pickup with manual brakes these larger cylinders fit both sides. GM Part # 18017570
- FAN FOR HEAT EXCHANGER
- CAT BYPASS TUBE
- HIGH STALL CONVERTER
- REAR AIR SUSPENSION
- COLD AIR KIT
- UNDERDRIVE PULLEYS
- LARGER TURBO
- LARGE BORE EXHAUST
- PRESSURE GAUGES - FUEL, OIL, ETC.
- CAMSHAFT
The stock cam is from the regular 4.3L engine so it's a fairly anaemic grind. The actual power gains from a cam change are unknown and, because of the low revving, grunt nature of the engine, really only benefits strengthened high revving (Above 4800 rpm) motors which have had the transmission shift points altered.
Stock Crane Intake Valve Opens
(Before TDC)42-Degrees 10-Degrees Intake Valve Closes
(After BDC)83-Degrees 24-Degrees Intake Valve Duration 305 (42+180+83) 214 (10+180+24) Exhaust Valve Opens
(Before BDC)78-Degrees 39-Degrees Exhaust Valve Closes
(After TDC)53-Degrees 15-Degrees Exhaust Valve Duration 311 (78+180+53) 234 (39+180+15) Intake Max Lift
(With stock 1.5:1 rockers)0.357" Exhaust Max Lift
(With stock 1.5:1 rockers)0.390"
- PORTED AND POLISHED HEADS
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- RACING TRANSMISSION KIT
- 40LB INJECTORS
- HEADERS
- PORTED UUPPER/LOWER INTAKE
- DFI OR SIMILAR AFTERMARKET FUEL MANAGEMENT
- SLICKS FOR REAR
- LARGER/STRONGER FRONT AND REAR DRIVE SHAFTS
- FORGED PISTONS & RODS
Recommended and proved pistons are the TRW-L2441. Some skimming work is required on the piston tops to lower the compression ratio back to stock levels. This is especially true when going 0.030" over size. The stock rods are only marginal at best and have an upper RPM operating limit of 4800. In 1992 GMC changed the design of the rods of the vin code "W"/L35 engines which required a speed range up to 5600 RPM. The connecting rod was strengthened in the shoulder area above the bearing bore with additional material to handle the higher loads and the broach slot was replaced by a spot-face. The additional 800 RPM raised the inertia load by 36% on the connecting rod structure. High speed cycling on connecting rod test fixtures and operation engine showed that the structure changes increased life by a factor of two at the 50 percentile level. These rods are available with GM Part Number 10201166.
Eagle Specialty Products now has H-beam connecting rods for the 4.3 at $461.25/set. Call (901) 345-5886 or email eaglerod@netten.net
- STROKER KIT