I am trying to give my daily driver a little more zip. I recently purchased a Walbro 307, adjustable fuel pressure regulator, and 37lb injectors. When installed what is the maximum boost I can provide without doing any damage? I know you will recommend a scantool, but I was hoping to be able to get by without one, I am not a racer. I also have a 3" downpipe, exhaust, adjustable wastegate, and an aftermarket boost gauge. The car has 79,000 miles.
The short answer to 'How much boost?' is 'It depends.'
Chances are slim that your fuel system upgrades will acutally allow you to increase your boost beyond stock levels. Several of the upgrades you have already performed aid airflow and efficiency. Because of this, you may already need more fuel delivery...at the same boost levels.
Aftermarket calibrations found in various chips may allow you to run slightly higher boost levels due to changes in timing and other parameters.
Your fuel's octane is also be a major factor in the maximum amount of boost you will be able to run.
In regards to the scan tool: It is not a 'race only' tool. Scan tools are reguarly used (in fact, required) for diagnosis of problems in all modern cars. Its nearly impossible to diagnose any modern fuel injection system without one. While many of the ones designed by those in the Turbo Regal community have several features to aid racers, a standard mechanic's scan tool (i.e. OTC, SnapOn, AutoXray, Diacom) would still be valuable in tuning your car. In fact, it (along with a fuel pressure gauge and boost guage) will help you to adjust your fuel pressure and boost for proper fuel/air ratios while tuning to avoid detonation.
Oh, ok, I was under the impression that with the added fuel I could add more boost. Do you think it is possible to get my car into the 12's with the setup I have? If not I may not even bother installing the upgrades.
With my 86GN I ran 13.2x@104 in street trim at 17psi with a upgraded fuel system and a Jay Carter Variable Timing chip. That is on a peg leg car so I couldnt leave very well.
FWIW, put the fuel system, DP and exhaust on it. Find someone around you that has a scantool and borrow it
get the car tuned right and you'll be happy. I'm sure with a bit more tuning and some exhaust work i'd ove been in the 12's in street trim with the 86. Chris Wilson
1985 T-Type 12.12@117 (3500ft elevation, no posi, 23psi)
1986 T-Type Bone Stock
I reached the high 12s through a stock turbo, stock downpipe, stock catalytic converter, and stock exhaust with stock injectors and on DOT tires. I don't think reaching the 12s with your combo AND some tuning will be a problem. See the 'recipes' at http://www.gnttype.org/techarea/recipes/recipepage.html and in particular, http://www.gnttype.org/techarea/recipes/recipe.html for a good indication of what incremental steps in the process may yield.
I want to upgrade my exhaust system ie downpipe, hi flo catalytic converter, quiet but performance oriented mufflers, a crossover pipe, and exit in the stock location. Choices range from Hooker, KBell, Walker Dynomax, Flowmaster, Random Technologies (Catalytic converter). Advice appreciated. Thanks John Saleeby
I personally have the 3" Hooker exhaust 3" CAT and if you want quiet inside the car, I would stay away from it. The drone inside the car at 55 mph, makes it hard to carry on a conversation. I would add though, that I love the sound from outside the car when my wife drives it, which isn't often.
Thank You Scott and Chris for the info.
John, you might want to also consider the ATR stainless system with Ultraflow mufflers (no drone, quiet inside the car), or the Hooker system with Ultraflows ...
Walker Super Turbos drone pretty badly, as do the Flowmasters....
What Ken says is very true. Ultraflow mufflers work great. No highway drone and they have very little backpressure. I have them on my otherwise $150 muffler shop 2.5" dual exhaust system and run mid 11's thru them.
Chris Bischof
http://perfauto.tripod.com