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not to mention ignition coil dwell....

voltage drop is always an issue. especially if the ECU doesn't see it to compensate for injector deadtime and coil dwell. I've had cars missfire and voltage at the ecu looks fine, but the coil voltage was low due to a high resistance contact in the ignition coil power relay and at 7000rpm the current draw through it was significant.

coil power is the square of primary winding current, so every amp is important.

ps..Just bought an 8374 1.05.. f**k you guys for making me do it!

Edited by burn4005
  • Like 2
1 hour ago, burn4005 said:

not to mention ignition coil dwell....

voltage drop is always an issue. especially if the ECU doesn't see it to compensate for injector deadtime and coil dwell. I've had cars missfire and voltage at the ecu looks fine, but the coil voltage was low due to a high resistance contact in the ignition coil power relay and at 7000rpm the current draw through it was significant.

coil power is the square of primary winding current, so every amp is important.

ps..Just bought an 8374 1.05.. f**k you guys for making me do it!

What's on there at the moment?

HKS GT2530s (was making 411kw at around 24psi) and a mines equal length front pipe, which sounds GLORIOUS. so I'm on the hunt for an equal length runner split pulse T4 manifold if anyone has a recommendation?

most manifolds seem to put the turbo right up front and cyl 1 runner is half the length of cyl 6 which affects the sound to my ear. I would like to find one where they're all the same length (for the high pitch sound more than anything)

It looks like the EFR compressor is massive so it needs to be located in front of the strut tower? or does placing the turbine between cyl 3 and 4 (like the old HKS and Greddy manfolds that they stuck a T04z on) still fit?

Its an R34 GTR btw.

Edited by burn4005
2 minutes ago, burn4005 said:

HKS GT2530s (was making 411kw at around 24psi) and a mines equal length front pipe, which sounds GLORIOUS. so I'm on the hunt for an equal length runner split pulse manifold if anyone has a recommendation?

most manifolds seem to put the turbo right up front and cyl 1 runner is half the length of cyl 6 which affects the sound to my ear. I would like to find one where they're all the same length (for the high pitch sound more than anything)

It looks like the EFR compressor is massive so it needs to be located in front of the strut tower? or does placing the turbine between cyl 3 and 4 (like the old HKS and Greddy manfolds that they stuck a T04z on) still fit?

Its an R34 GTR btw.

664B16D5-A6E9-4D53-AD0A-61AFB2982E1E_zps

26 based block, 8374, 6 boost manifold.

 

4A2AA073-54A8-4AFB-BFC2-9E2F50350777_zps

 

30 block, 8374, 6 boost manifold

 

 

3 hours ago, Lithium said:

Hahaha that's awesome!! Was looking forward to seeing what the S300SX could do but this is a more than acceptable alternative :D

When's the next MickBBQ? Lol

Would have been awesome to see what the old 83/75 could do but this deal was too good to pass up.

 

book your plane tickets then

  • Like 1
So the fact that because of voltage variances the injector opening time changes and the fuel pump changes flow rate is actually a good thing? 


YES "in the beginning stages of a tune" I welcome this type of adversity.
1 hour ago, Piggaz said:

The 8375 was nosing over uptop on the 2.6. It prob wouldn't have made much more if any on the 2.9.

Yea but I wanted to see how responsive I could get it, would have destroyed most twins ???

2 hours ago, mr skidz said:


How do you find the time to write stupid shit like that, don't you have Pokemon to catch?

I completed an online course and now i'm an expert in Pokemon Catching.  The writing stupid shit market seems pretty saturated.

  • Like 5
12 hours ago, Lithium said:

I see you are laying on the being a tuner thing quite thick, so respectfully while I'm no professional tuner I *have* dabbled somewhat and I tend to take the angle as a "ch00ner" that it's worth making sure that everything you are working with is doing their job properly and if there is some outlier from the norm, voltage being one of the more serious areas to be misbehaving when dealing with EFI tuning imho - then it's very much worth investigating what is causing it.  Feel free to call or think of me as a rookie as I am compared to many, but building on a shaky foundation seems like a silly idea - no matter how insignificant the shakiness seems.  It may not be what you think it is, and if you build a huge complex structure based on a shaky foundation it's very possible that sooner or later show it's true nature and provide much bigger headaches than if you just did it right in the first place.

OK - I'm surprised you decided to blame the turbo as opposed to consider that there is something not working right with the overall setup, considering the overwhelming info and collective experience on EFR turbos that indicate what you have experienced is WAY outside of usual.  Everything working right and trying to set low expectations I'd say that you should expect an EFR8374 to feel at least SLIGHTLY better than an XR6 Turbo, in regards to the EFR7670 - if you ignored the fact that it has really nice aero and an ultra light turbine etc and just compared like for like it is a significantly smaller turbo.  All other things being equal it should spool faster and be more responsive, noticably so.  Same goes if you put a GTX3076R in place of the XR6 turbo - but all evidence points to the EFR being very noticably more responsive than a GTX3076R.

Given you've decided to blame the turbo, you seem like you might be measuring a lot of the stuff in here as being fanboism and just rushing for the latest greatest - that's not how I roll, I just look for the best ways of making good performance and try and work out if or what isn't working right - I did spend a period of time in this thread warning people off EFRs due to the supply and reliability concerns which popped up in the first years after they were released, I'll call a spade a spade and be conservative and polite about it.  What you are saying doesn't add up and if I was involved in a car which had an EFR7670 which didn't look flash compared to a stock XR6 turbo then I'd treat it exactly the same as if I was tuning an RB20 with a 20G and it wouldn't make over 160kw, I'd not say that the RB20 can't make over 160kw nor would I say that 20Gs can't flow that much, the odds are something isn't right and there is a lot of improvement to be had by ironing it out. 

In terms of "not performing well at low boost" that's an interesting one, never heard of that - I know I've heard of people throwing that kind of thing around for Precision and other turbos at times but it's kindof a non-thing, you can't really say that about a turbo as a general term.  I can't answer that question as I have no idea what power you're looking for, what your engine/setups flow will be like etc so I really can't say whether it would perform or not on your setup.  

Generally speaking the EFR efficiency ranges seem to "scale" fairly well through the pressure ratios until you reach the max safe flow they can provide, so if it will perform at 32psi without choking then it should also be fine at 20psi.  If you engine outflows that then you've not matched the turbo correctly, the same applies whenever selecting a turbo.

The car looked to be a well sorted bit of kit...it was a std bottom end but ran full bolt on Full Race manifold, twin gates etc on a neat S15.  

 

Its one result...so not right to judge. That EVO is a bit looneybin that its a stroker and big boost.

 

The 7670 may not be the gun conbination thatvthe likes of 8374/RB26s are.

 

I look around and there are very few SR results with EFR turbos so i just dont know...i had hoped it would blow away a GT3076...i just need to see more results for the 7670

 

6 boost seem ok, note they seem to have two variety's, the normal symmetrical and the moved forward ones, not sure if they're equal length. Or if they clash with stuff, i'm pretty sure one as per piggaz would clash on R32 factory power steering and aircon which are both longer.

 

Fullrace has similar issues though from photos look like 4-5-6 are slightly different lengths to eachother. Also have clash issues with 32's (can't remember if its PS or AC). RAW brokerage will sit too high up, or did, might be best asking if they've fixed that problem. Best bet is a custom one but it can take longer and cost more.

 

6 boost works perfect on R32 accessories.

Full race needs smaller AC compressor and lines to work on R32

RAW told me they had no plans to change theirs. WAY too high for RB in a GTR. Deck height change to RB30 would only complicate things.

I'm running 6 boost and like it a lot.




And about my fuel issue. 12.5V will not net me enough fuel supply on my pump. I noticed the issue because haltech caught my fuel pressure differential and shut the car down. It used to be 13.5 or so. Aeromotive tech says a fuel pump can lose up to 40% flow from 13.5V supply down to 12.0V. I belive him. So far I think it's an old or shorted wire. Starts fine and holds voltage at 13.4 or so then within minutes voltage is plummeting as things heat up. New alternator didn't change anything. I'm thinking old crusty wire is adding resistance as it heats up.

But yes it's Handy on checking your dead times in the haltech by turning on AC and watching voltage drop and resetting dead times to maintain AFRs. Then you can go all the way to adding a battery charger to go the other way.
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