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Stock Block/Stock Head +7PSI, E85, NO TUNE+Wire Tuck+ABS Relocate (01/17/11)

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01-20-2011, 11:30 PM

#421

johnhawkins

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Quote:

Originally Posted by ScionFred

With E85 550cc would be about the same as oem with pump gas. You'd have very small fuel trims in CL. You'd need to raise the fuel pressure to 70psig (700cc) for 300bhp. Pump gas is very different. IMO 550cc might be too big for the ECU alone. You may need a MAS signal modifier like your Neo to help keep the ECU happy.

IME the ECU does very well with up to 20% LTFTs and +/-10% STFTs but not very good beyond that. In theory the ECU can set a -25% LTFT and still trim another -20% STFT but it doesn't do it well. 550cc is 50% larger than stock. Lowering FP in vaccum would help. IMO you want to flow less than 500cc in vacuum or skew the MAF signal by say -15%.

Arent the stocks 370cc?? If so 550's would be an increase of 33% right?
Then even if I drop the FP in vacuum to say maybe 38-40psi would go much lower.

01-20-2011, 11:32 PM

#422

ScionFred

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Quote:

Originally Posted by johnhawkins

Would the neo even work?? If the clamp is set at 4.7v or so and that is the signal the Neo would intercept so the Neo would have to give the ECU a new signal. If it gave a signal it would have to be greater than 4.7v correct? Would that just throw the 101 code anyways? or am I tottally not understaing this. I was under the impression the ECU cant see a signal greater than that.

I've never used the Neo but I'm assuming that it is a simple voltage signal modifier like the MAF table in the FIC, etc. If it receives 2v in you can program it to send 1.8V out. If so, it should also function as a MAF clamp. Just set it so that it never outputs more than say 4.7V. Use your RRFPR to add fuel beyond the clamp point.

If you did need to add a clamp it would go after the Neo and before the ECU.

01-20-2011, 11:41 PM

#423

ScionFred

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Quote:

Originally Posted by johnhawkins

Arent the stocks 370cc?? If so 550's would be an increase of 33% right?
Then even if I drop the FP in vacuum to say maybe 38-40psi would go much lower.

550 - 370 = 180/370 = 49% more flow

550cc @35psig would net 493cc flow rate

How much can your FPR raise FP?

Useful calculators here:

http://www.rceng.com/technical.aspx

01-21-2011, 12:11 AM

#424

johnhawkins

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Quote:

Originally Posted by ScionFred

550 - 370 = 180/370 = 49% more flow

550cc @35psig would net 493cc flow rate

How much can your FPR raise FP?

Useful calculators here:

http://www.rceng.com/technical.aspx

It goes up pretty high - But I wouldnt really want to exceed 70psi max fuel pressure prob less.

If I set my BASE fuel pressure @ 42psi what will it be in vacuum when I attach the vacuum line???

With the OEM fuel pressure regulator, the base was 43.5psi right? Did the fuel pressure change under vacuum with the OEM FPR???

01-21-2011, 12:24 AM

#425

ScionFred

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Quote:

Originally Posted by johnhawkins

I was really asking about the FPR's range. Can it do 35-55psi? 35 might keep the ECU happy and 55 would be good for 350bhp with 550s.

The oem fpr doesn't see vacuum or boost. I've heard that it produces roughly 45psi at the rail.

Sorry but I have no idea how to setup a RR-FPR.

01-21-2011, 12:32 AM

#426

johnhawkins

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Quote:

Originally Posted by ScionFred

From what ive read - When installing the rr-fpr you keep the vacuum unhooked to set you BASE fuel pressure. Then once you hook vacuum up it will acually decrease the fuel pressure at vacuum/idle to a certain amount that differs based on the engine.

The FPR I have is a 1:1 rising rate so If I ran my base pressure at say 40psi and my vacuum/idle fuel pressure is at 35 (using this number just for this equation) and I put 10psi of boost pressure on the turbo- the max fuel pressure it would be is 50psi.

01-21-2011, 01:30 AM

#427

ScionFred

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Ok, cool. I forget the actual ratio but every inch of vacuum equals roughly 1/2 psi so at 40psi base you'd have ~30psi at idle.

01-21-2011, 02:22 AM

#428

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Quote:

Originally Posted by ScionFred

Ok, cool. I forget the actual ratio but every inch of vacuum equals roughly 1/2 psi so at 40psi base you'd have ~30psi at idle.

really wow 10psi!!!! so i can up the base pressure a lil

01-21-2011, 12:11 PM

#429

OuterHeaven

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If you have 20 in hg vacuum at idle then your regulator should lower pressure by 9.8 psi.

01-27-2011, 12:48 AM

#430

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Quote:

Originally Posted by OuterHeaven

If you have 20 in hg vacuum at idle then your regulator should lower pressure by 9.8 psi.

sweet thanks man

01-27-2011, 06:51 PM

#431

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Just picked up a 2011 Hyundai Sonata today! Looks great compared to other Hyundais I remember in the past. I will post some pics up later. Not doing much to the Sonata since I have the tC for fun. Butttt I did order 12" hifonics sub 1100 mono boss amp. Going to put 20% tint all around and plan to de-badge the rear trunk. Also going to remove the stock hub caps and roll with the steelies. God I love the new car smell.