Need advice on mods

[Bigreddawg]

Ok, I got the Walbro 307 in with the hot wire kit and I had 40 psi fuel press with stock reg. but put an adj. one in anyway and set it to 43 psi. This was with the vac/boost line off ofcourse. I have a 3" exhaust on and need to get this car moving. I ran 15.75 @88.5 with lots of spinning(no limited slip) with it and it was only knocking off the line in first when the boost was pegging the dig. boost gauge. Can I just inc. boost with an adj. wastegate actuator now or should I get a chip instead? Or do you need to do both? It still has the stock 28# injectors and 75k miles. I will put a 160 deg. stat in, new gas filter, change the oil to 5w30 syn and block off the coolant lines going to the throttle body also but I know not to expect much from this. Any help will be greatly appreciated, thanks in advance.

 

[cool 84]

If you want to make the biggest differance at the track, get some slicks, set the boost at 20psi (anymore and you'll slow down), add a race chip with around 26 degrees of timing, K&N filter or at least get rid of the stock air box, gut the cat or unbolt the downpipe from the cat and run open exhaust, and get a scan tool. Tune for 0 knock and start turning the fuel pressure down until you get around 780 milivolts on your 02 sensor. Make sure to run 110 octane or better.

Other things are to make sure the TPS is set right and the car has a good tune up. With these mods in place and good tuning you should be able to knock around 1.5 seconds off your time. In fact my dad's car went 14.0 @ 100mph on regular street tires through the stock exhaust with the above mods.

 

[Bigreddawg]

Thanks alot for the info. Would it be unwise to try and turn up the boost w/o a chip?

 

[TurboRegal84]

It's fine to turn the boost up on the stock chip.....Remember...to INCREASE the boost make the Rod Shorter...to DECREASE make it longer!

Have fun!

 

[Bigreddawg]

The knock I still have when first punching it, could that be caused from having to much gas? If so can the car be leaned out there somehow w/o leaning it on the top end?

 

[CHECKMATE]

Usually you ADD fuel to stop knock. If you lean it out you will knock more. (run hotter)

 

[WH1]

Might want to check your motor/trans. mounts; alot of times these being broke will cause knock especially off the line or when punching.

 

[Racetronix]

Bigreddawg,

You might want to put a fuel pressure gauge on your hood when you are going for a pass. If your base pressure is 43psi and you are running upwards of 15-20 pounds of boost your max fuel pressure would be 58-63PSI. This is right in the range where a GSS307M pump starts to open its bypass valve and its volume drops way off. As there is a moderate window for this specification yours could be on the lower end and opening early. This is why I only recommend a GSS340M for a modified TR application!

http://www.gnttype.org/techarea/fuelsystem/pumpflows/gss307340.gif

If you notice the fuel pressure dipping at all or not increasing 1:1 with every pound of boost then you might have a problem there.

I hope that you have a new fuel filter installed?

As cool 84 stated, checking your O2mV is a good idea as well although this is a relative reading and can not be used to identify the problem component(s) but rather give you direction. Some street chips have excessive timing in them so if you have a stock chip that would be best to try. It is a known fact that the interrupter ring for the crank sensor on the TR has a wide range of variance when they are pressed on at the factory. I have seen TRs base timing vary considerably +/- from TDC so one car to the next will not have the exact same spark advance using the same chip.

Jay Carter's and Red Armstrong's street chips tend to be on the more conservative side for timing and seem to be very popular with the masses. Depending on the octane of gas you are running you might have to get a milder chip for pump gas use.

When you are playing on the edge a couple degrees of timing or pounds of fuel pressure can make the difference between a well performing car and a membership in the 'crank in the dirt club'.


Good luck!

Jack

 

[Bigreddawg]

Thanks for all the advice guys, I appreciate it.