Hey guys, I have a race coming up this saturday with a AWD DSM. I was wondering if it would be any benefit to up the boost to 14 psi rather than say 10-12 like i've been hearing the tmic can only handle that. Would this yield me any more power for just that race? I only run 7-8# daily. I have a CO2 sprayer for the IC so heat soak shouldn't really be a problem. My setup is as follows

87 T2
Full Corksport Turbo Back 80mm exhaust
3" TID
SAFC2
Walbro 255
720cc secondaries
STOCK TMIC
TurboXS RFL BOV
Magnecor 10mm race wires
new NGK plugs
massive 40mm ported wastegate
Custom Wastegate dump pipe
Busta Manual Boost Controller

Thanks guys

 

Also, Right now I have my 720's detuned approx. 24% after 4000rpm. Just trying to get them back to stock specs (Does this sound like a reasonable number) (1100cc/1440cc) ( ~24% more fuel correct?) Do you think it would be necessary to add fuel at say 12-14psi or so?

thanks again

 

Yikes. You are forgetting about the primary injectors that are firing as well. Above 4000 rpms stock you have 550 x 4 = 2200cc's of fuel. With the 720cc secondaries, you have (550 x 2) + (720 x 2) = 2540cc of fuel.

2200/2540 = .867 = 86.7%

100 - 86.7= 13.3 % more fuel.

To get back to stock mixtures plug in -13 percent after the secondaries have come back online.


The biggest problem with the stock top mount is going to be heat soak. I've covered my top mount with ice before making a run, and it's all gone by the time I pop my hood again. I think you're ideal pressure to run is going to be between 12 and 13 pounds. Anymore than this and you're not only starting to overheat the intake air from inadequate cooling, but you're drifting outside the peak efficiency range of the stock turbo.

It's hard to say what you're safc settings should be. Without an EGT or wideband you're really just shooting in the dark. With the walbro in, I'd actually be willing to bet that you would be fine with stock injectors. I would add a small amount of fuel in the midrange at the least. For ex:

Hi map: 4k = -9 4.5k = -8 5k = -9 etc...

At 11 pounds on the stock turbo with just the walbro I put down 232 rwhp and my a/f ratio's were in the mid 11's.

 

I'd do 14 on the TMIC, probably only because I don't really care if I blow my engine.

 

Co2?

 

Thank you so much for your information. Er yeah I completely forgot teh primaires lol. my bad. I think i'l just add 3-5% fuel after 4K and call it a day.

 

Carbon Dioxide. Cheap ****, compressed in a paintball gun tank. I figure it might help to battle the heat soaking. I have seen it be used before instead of Nitrous. I dunno if it even works, but its worth a shot.

 

For general reference:
A 10 pound CO2 fire extinguisher is just about right to ice a 6-pack of beer.

 

^^^LOL

CO2 does work. It's basically a cheaper, less powerful Ntercooler kit. Just get out, hose down the intercooler, and let it fly

 

Yeah CO2 is an option. Its not like Nitrous at all though. CO2 in liquid form (compressed) turns directly into the solid form when it is quickly released in the air. Everyone has heard of dry ice...this is what forms. Spray liquid CO2 all over your IC before you run and the whole IC is caked with dry ice at about -109.3 degrees fahrenheit. It won't last too long before it all turns back to gas though so you need to spray it just before you run.

-Joe

 

couldn't you just leave it spraying a small amount during your entire run?

 

The problem with that is that unless you make a proper venting system, you will get CO2 into your intake and will kill your power.

-Joe

 

i think gsracer's math forgot to take the upgraded fuel pump into account but either way if you pushing that much boost get it on a dyno with a wideband so you don't blow it up

 

yes I am going to the dyno on August 1st (have appointment booked ) I just need a safe setup that will give me the max power, without justifying safety with my mods. I think I have more than enough fuel to push the turbo to its limits. It is just a matter of being too rich. Do you think if I just leave the secondaries 0% (ie stock fuel) that would be hella rich at 12psi?

 

Probably not insanely rich. Your primaries are stock right?

-Joe

 

yes I have stock primaries.