Turbo Set-up Questions.

[1999silverGSX]

I have a 99 GSX a/t. My goal for this car is 400 awhp. I recently purchased a 190lph fuel pump. I intended on going with a e3 16g, but i now have decided i want something that will produce more power ( around 400 awhp which i have read the e3 wont do ). I am looking in to Buschur's 20g. My question is how far will a 190lph pump and 680cc injectors take me with this turbo. I am on a budget im not really trying to go with a 255lph pump and afpr.

 

[DGajre777]

According to FPs website, the 190 pump is good for 400whp. There are many turbos that can put you where you what to be, but you will need other supporting mods for it.

 

[Quasimondo]

I was iffy about it at first, but I did the math, and it appears that a 190 could support 400 hp.

To clarify, according to the formula HP = (lb/hr)/BSFC (gasoline typically has a BSFC or .5), in theory to support 400 hp, you'll need a pump that can push 200 lb/hr of fuel. Convert to LPH, that's only 126, convert to GPH, that' 33. Sounds good, so far.

So now we check the flow rate of a Walbro 190. At 13.5 volts, and a base fuel presure of 42 psi (what most injectors are typically rated at) this pump checks in at 49 GPH. Assuming that you push that turbo to approx 20 psi, with a 1:1 fpr, that drops your flow to approx 42 gph.

So there you have it. If you saw my entry prior to the edit, I didn't do the math.

The hp formula is here:
http://www.autoperformanceengineering.com/html/pump_faq.html
The volume conversion page is here:
http://www.csgnetwork.com/injectorvolcalc.html
Flow rates for walbro 190 and 255 pumps are here:
http://www.autoperformanceengineering.com/html/fpspecs.html

With that said, I still prefer overdoing things to be on the safe side. With all four injectors maxed out, you'll be pushing 2700 cc/min (247 lb/hr, 156 lph, 41 gph). To me, I think this puts that pump very close to not providing enough fuel to keep those injectors happy, and if you end up pushing more than 20 psi, then that fuel pump will not be enough.

 

[CanadianTSi]

A rewired 190 will support a little more than 45lbs/min of Airflow, which would be close to 400whp depending on the dyno.

 

[1999silverGSX]

What size injectors would it take to run this 20g to its full potential? I know 680's are good for using a 16g to its full.. Ovbiously a bigger turbo would require bigger injectors 16g to 20g but what i am trying to say is... how much will i be limited to?

 

[DGajre777]

What size injectors would it take to run this 20g to its full potential? I know 680's are good for using a 16g to its full.. Ovbiously a bigger turbo would require bigger injectors 16g to 20g but what i am trying to say is... how much will i be limited to?

What are you planning to use for fuel control. If you plan to get DSMLink, ECUPlus or a chip with EProm ECU, you can use the biggest injectors you can get. I would go with 650s if you plan to go the S-AFC route and 750cc+ if you get DSMlink.

With smaller injectors you could be running high IDC (Injector Duty Cycles), if you get bigger injectors, you'll run low IDCs.

 

[1999silverGSX]

What are you planning to use for fuel control. If you plan to get DSMLink, ECUPlus or a chip with EProm ECU, you can use the biggest injectors you can get. I would go with 650s if you plan to go the S-AFC route and 750cc+ if you get DSMlink.

With smaller injectors you could be running high IDC (Injector Duty Cycles), if you get bigger injectors, you'll run low IDCs.

I plan on using S-AFC for now. So Higher Duty Cycles mean that the injectors are close to maxing out? as to where if i have lower IDC's i still have room to grow or up the boost?

 

[fourreGsixty3]

So are you thinking of the TD05H bastard 20G, or the TD06H 20G? I agree here with Dee. The ECU chip will be the cheapest, and Andymoraitis has one, and he is running pretty high HP without a problem, and DSMLink is fun to use, and pretty easy once you get use to it. With either of those you are able to compensate for large injector's. The SAFC isnt the best tuning device since it lies to the ECU saying that there is less air flow comming in, and you cant run that large of injector's with it...660s at the limit's.

 

[fourreGsixty3]

I plan on using S-AFC for now. So Higher Duty Cycles mean that the injectors are close to maxing out? as to where if i have lower IDC's i still have room to grow or up the boost?

Yes higher IDC means they are working harder, and will burn out quicker. Lower IDCs allow for more tuning room, and room to play with. Since you are using the SAFC you shouldnt go above 660s, and you will ###### upgrade your injector's to 720s, or 850s if you start running mid-high 20s in boost.

 

[Quasimondo]

The most any injector should ever run is at an 85% duty cycle. Any more than that and you run the risk of burning out the injectors. 680's might be pushing it with the SAFC. The problem with large injectors is that to get them to run right you have to lean them out so much that it affects your timing, giving you too much advance. If that does become a problem, your best bet is to find an eprom ecu and go with either dsmlink or order a chip from keydiver.

 

[JayRolla]

Just so you guys know andy did run out of fuel with his 190 on a 16g. It was when he installed his comp cams. It also was on his 2.3stoker. There is a guy running 720's with safc on a 1g with the higher ignition map. He got his knock down to 5 counts at 20psi. Very surprised he got his knock that low.