Bigger turbo, boost and fuel question

[Fozbo]

Let me start off by saying that I do know about the hazards of upping boost without adding more fuel.

My engine is currently being machined and the lower end assembled. The list is as follows:

Completely rebuilt head w/3 angle valve job and some mild porting
Cometic MHG (on it's way)
Wiseco pistons
eagle rods
ARP head/main studs
new pumps/gaskets/seals/bearings/etc.
Full T4 setup with tubular manifold, turbonetics 62-1 turbo, and 50mm wasgate with 10 psi spring.
New godspeed intercooler (25 x 6.5 x 3.5 w/3" inlet/outlet)
3" hard pipes
3" exhaust
K&N FIPK

That is the major stuff, no fuel mods/tuning device to speak of. My question is this: will I be safe running 10 psi until this summer when I have money/time to do my second stage (MAFT-pro, larger injectors, FPR, fuel pump, etc.)? Does anyone know what the calculations are for flow rate and boost to stay in good A/F values? Is the stock fuel cut based on boost or flow? Does anyone know the stock ct26 flow numbers so that I can estimate the flow rate per psi that would be safe?

Many many thanks in advance, just trying to plan this out before I start putting it together.

Edit: basically what stock ct26 psi does 10 psi on a turbonetics 62-1 turbo translate to? Will I need to get a smaller psi spring for now to be safe?

 

[suprahero]

10 psi shouldn't hurt you at all if you can run it without hitting FC. The newly rebuilt motor will be fine. I don't know how to do the calculations, but 10 psi isn't hardly enough to hurt a strong motor. Fuel upgrades will help you alot with your horsepower though. Keep us posted with your results........lol

 

[Reign_Maker]

Let your wideband tell you, or your dyno tell you whats safe... Its not about what pump you have or what fuel system or engine management yur running... If you tune the car, and the A/F numbers say 10psi is ok, then 10 psi is ok... If it says 9, or 8 or 7, then just go with whats safe... DO NOT GUESS ON THIS! And dont take the advice of what someone might "think" is ok to do... The sensors dont lie, so long as they are in proper working order...

You shouldnt take something like this on someone's word, or personal experience, because with experience, every one is different, every car, every scenario, etc, is different... And just because you respect someone's opinion, or experience on this, wont make it so with your individual car... Take me for example, I have alot of experience with these cars, and from what I see, I seem to get alot of respect and people look to me for answers and guidance, so if I tell you to run 15psi, would you believe me? But I did it! So its ok for you to do it too! Right? Wrong... Spend the money on this car on the dyno, you've spent sso much time, money and love on this motor, so what's a few hundred bucks on a dyno?

Good luck man...

 

[tookwik4u89]

Agreed^^^^I didnt see a wideband on your list, that should be the next thing you buy. It will allow you to use the AFR tracking on the maft pro. Talk to Dr. J

 

[Fozbo]

Yeah, I forgot to list the wideband. The maft-pro's ability to work in conjunction with the wideband and other fuel/tuning modifications is actually one of the primary reasons for me picking it.

Thank you for being upfront about it. I understand that dyno tuning would be the best route, and I plan to do that when I get wideband/maft-pro/fuel upgrades. I was really looking for any knowledge about flow vs. psi vs. what the stock ecu reads to determine fuel cut.

I guess that once the car is broken in, I can just take it to a dyno, do a couple pulls leading up to 10 psi and examine the A/F ratios? If it stays richer than a 12, then I should be alright until I get the proper mods and tuning to start inching up the boost? Would this be a wise course of action?

Sorry about all these stupid sounding questions, I would rather look dumb now and be smart later than the other way around.

 

[kylefoto]

I'm currently running a 60-1 on stock fuel system, stock intercooler, stock internals, with a 3 in exhaust, and it's at 9 or 10psi, I'm not sure how much more power the 62-1 turbonetics one will translate to in relation to that, but I think you should be fine...

 

[Reign_Maker]

Fozbo, you didnt ask any stupid questions... As for fuel cut on the stock ecu, expect it around 11-12psi, but that can also change with the ambient temps outside, say for example, if its really cold, the air will be denser, and you can hit fuel cut earlier... Good luck man, hope we helped...

 

[aye mate]

Fozbo, you didnt ask any stupid questions... As for fuel cut on the stock ecu, expect it around 11-12psi, but that can also change with the ambient temps outside, say for example, if its really cold, the air will be denser, and you can hit fuel cut earlier... Good luck man, hope we helped...

It should come on earlier with a larger turbo, right?

 

[Reign_Maker]

It should come on earlier with a larger turbo, right?

That's true, because a larger turbo moves more air...

 

[s383mmber1]

That's true, because a larger turbo moves more air...

Yup!

If it was me, and i spent ALL that money on internals, and everything, i really wouldn't want to blow it up :icon_bigg

AT LEAST a wideband and maybe AFPR

 

[starscream5000]

I wouldn't even start that motor up for the first time unless you've got a wideband installed. With that turbo, and the wastegate set at 10psi, I'd say you'll be hitting fuel cut pretty much every time you hit full boost. That turbo "should" be moving lots more air at 10 psi than the CT would.

 

[aye mate]

I would say at least get an AFPR and Walbro pump. Thats like maybe 400 from SupraSport. That way at least you'll be rich and not lean.


BUT get a WB before anything.

 

[Fozbo]

Well my plan is to get it together, break it in, and then go to a local dyno about 10 miles away. 75 bucks for three baseline pulls with a WB, using more gas/boost each time. And yes, I do have the self control not to drop it and go full boost during break in . That should tell me how lean/rich I am. If the numbers are consistantly rich enough, then I know that I will be able to run the 10 psi without problems until I get my WB/maft-pro/fuel upgrades/etc. this summer. But if the A/F comes too close to being lean at 10 psi (which I doubt, but I can't say til I see it) then I will figure out what boost is and get a spring for it. Sound sound?

 

[starscream5000]

^Sounds good .

 

[MRSUPRA]

You shouldn't have any problems as long as you have a 10psi spring. Of course 10psi won't be much fun.

 

[starscream5000]

I'd say 10 psi on that turbo will be plenty fun .

 

[Fozbo]

All I know is that after driving a sebring this summer and a mini van this fall, anything will be fun .