turbo engine tuning secrets -
featuring original research

By Josh Straub, 2009


Key Ingredients to a Fast Truck

Syclone Modification Stages

Stage 1:
How to Get a Stock Truck Deep in the 13's

Tuner's Guide to DataMaster

Real World Tuning Example:
Vortec/PT67GTQ Syclone on C16

Performance Roadmap: Syclone 4.3L Turbo V6

3 Bar Chip Tunes for Download

My 1991 Syclone

11.45 @ 117 Budget Build Spreadsheet

Vortec Heads Budget Spreadsheet

Racing Videos

Turbo Grand Prix

My 1990 TGP


Unfreezing Frozen Windows Applications
Stage 1 Stage 2
Stage 3 Stage 4
Syclone Modification Stages
optimize your results by building in a logical progression

It makes sense to stop and think about where you and your truck stand compared to all Syclone/Typhoon tuner/owners. You don't want to bite off more than you can chew, by throwing Stage 3 parts like ported heads and race cams on your Stage 2 (or 1!) stock turbo truck, for example. All you'll end up with, is an expensive truck that underperforms even some Stage 2 trucks and nothing to show for your extra money invested.

I created these "Stages" to match what I believe are the best combos for our trucks, in terms of skill, bang for the buck, etc.

Stage 1 Stock Truck: bone stock plus "free mods" like air filter, thermostat, etc.
1/4 mi. performance: 13.0 - 13.8 at 95-102 MPH on 93 octane pump gas

Stage 1 means at least the motor, turbo, transmission, torque converter, and chip are all factory stock. Every Stage 1 truck should have a solid tuneup. Knock retard and boost levels need to be monitored via laptop datalogger.

See "How to Get Your Stock Truck Deep in the 13's" for a solid guide on running with the fastest Stage 1 trucks.

Stage 2 High Boost Stock Motor: modified chip and boost controller used to run up to 20 PSI with stock turbo, and up to 25 PSI with larger aftermarket turbo (PT44 - PT54)
1/4 mi. performance: 11.7 - 12.7 at 103-114 MPH on high octane fuel

High octane fuel is used to allow boost beyond the factory 15 PSI level. The stock turbo typically responds with gains up to 20 PSI boost (12.2 - 12.5's). Installing a turbo upgrade allows further gains up to 25 PSI (high 11s). Either race fuel, or alcohol injection will be needed, since 93 octane pump gas is limited to the stock 15 PSI. The high boost of Stage 2 requires heavy datalogging/monitoring to stay safe. The fastest times will be achieved with custom chip tuning to really squeeze all possible horsepower out of the stock motor. However, I did run 11.79 @ 114 (video) with an off-the-shelf Ultimate chip for stock injectors (no chip tuning whatsoever).

Without chip tuning, the problem you begin to run into is a truck that performs well at WOT but suboptimal driveability around town (or vice versa). Chip tuning allows you to make necessary adjustments to "Have your cake and eat it, too".

It will feel like magic the first time you get your truck running properly at 20 PSI on high octane fuel! Stage 2 is where you get a solid handle on the tools (DataMaster, wideband O2, etc.) for making safe power, and where you learn to identify & solve problems like what spark plug gap is best, when your cap & rotor need replacement, and what boost level makes the truck run fastest.

Alcohol Injection is the key for allowing a street truck to run the same high boost tune on the street as on the track. Low 12s are where the stock 700-R4 transmission begins to fail more rapidly. Once yours wears out, you'll need to upgrade to either a well-built SyTy 700-R4 ($2000), or the superior 4L80-E ($5000). Bigger turbos also require a high stall (2500-2800 RPM) torque converter, which also requires a transmission rebuild. (High stalls on stock transmissions don't work very well.)

Stage 3 Modified Heads and Cam: stock block/crank running L35 or Vortec cylinder heads with aftermarket camshaft, raising shift RPM from stock 4500 to 5000-6000 RPM. Large turbos in the PT51 - PT72 range, chip tuning, and Wideband O2 sensor are all mandatory. This stage is typically the limit of real streetability.
1/4 mi. performance:
12.0 - 12.7 at 104-112 MPH on pure 93 octane pump gas

10.2 - 11.6 at 115-130 MPH on high octane fuel

A heads & cam upgrade is what will really transform your stump-pulling 4400 RPM stock motor into a well balanced midrange screamer! It also "automatically" makes your truck faster on pump gas (or any boost level for that matter), since the heads & cam determine the base horsepower at the engine (before boost).

A high stall (2700-3500 RPM) torque converter is mandatory at this level, along with an extremely well built transmission. Your local transmission shop's 700-R4 doesn't stand a chance behind a high boost Stage 3 motor. Only a few well built 700-R4s will live a decent length life here. The BEST solution is a 4L80-E conversion! The 4L80-E is a direct descendant of the mighty TH400, and can handle up to 1600 HP / 1600 LB-FT TQ, with electronic shift programming, still a fully streetable automatic overdrive!

I don't recommend ported/upgraded heads and camshafts until Stage 3. In fact, I specifically recommend against it for Stage 1 or 2. It's a very uncommon combination and few people have well established tunes for it. One of the worst combinations (in terms of reaching maximum horsepower) is a heads/cam Stage 3 motor, crippled with a stock turbo.

Want to read about tuning a Stage 3 modified motor for high boost? Check out: Real World Tuning Example: Vortec Heads/412 Cam PT67GTQ Syclone on VP C-16 at High Boost

Stage 4 Highly Modified/Experimental: aluminum heads, headers, strokers, engine transplants (small block chevy), shift RPM in the 6000-8000 range, turbos in the 74-88mm range, boost 20-35 PSI on race fuel, lots of custom fabrication.
1/4 mi. performance: 8.50 - 10.50 at 125-160 MPH on high octane fuel

At this point you will need to either be, or in intimate contact with, an accomplished EFI tuner as well as have (or have access to) strong fabrication skills. I would estimate that 9 out of 10 trucks that start building this stage, never even get completed due to the overwhelming amount of money and work required. Only the most strongly committed with strong resources will see single digit results.

2007-2008 Josh Straub Home | Syclone | Turbo Grand Prix | Computing | Contact
  Last Modified: Thursday, 25-Jun-2009 20:07:51 UTC