Jump to content
SAU Community

Recommended Posts

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.
  • Like 1
Guest
This topic is now closed to further replies.



  • Similar Content

  • Latest Posts

    • GCG is a good company, they're a major distributor for Garrett in Japan as well.
    • Nah, OEM washer bottle and brake fluid reservoirs are fine I don't know what it is with the plastic that Mazda used, some plastics, like the washer bottle and brake fluid res are fine, and still look new after 20 years use, where as the coolant expansion tank, and PS reservoir, that I replaced with new OEM items when I first got the car, turned yellow and started getting brittle a few years later If the dirty yellow stained plastics didn't trigger me there wouldn't be an issue, but they did, much like the battery bracket....... Meh As for going back to work full time to support car stuff, nope, why, because I own a Mazda NC MX5, not a Nissan R series Skyline 🤣
    • I've never heard of CJ-motor, so can't advise you on them. I'd just go straight to GCG for a GCG highflow though. Seems no point to use a middleman. I'm somewhat surprised that the price on the CJ site is lower than the GCG retail price. Even though CJ would get a discount of some sort, you would hardly expect them to give up so much margin. Maybe the price is out of date? Having said that "I'd go to GCG"...when I did my highflow, I went to Hypergear. I did this https://hypergearturbos.com/product/rb25dethighflow/#tab-dyno-results with the R34 OP6 450HP profile. With the BB centre (extra $400) and intially with the standard boost actuator, but I eventually got him to send me the high pressure one when I got to the point of being able to actually use it. Ends up costing the same sort of money as the GCG highflow, but this is, of course, the turbo that I KNOW has a shorter length core and so moves the comp cover rearwards. The GCG apparently doesn't do that. My mechanic also swears by the GCG highflow, given that we have another turbo rebuilder who does something essentialy the same as theirs, using Garrett wheels. He says it stands up at really low revs and makes good power. I haven't pushed my HG highflow past ~240-250rwkW yet (should have a little more in it, but unclear how much) and it does have a fairly gentle boost ramp. OK, it's much better now that I have gotten my boost controller tuned up on it.  A lot of my earlier unhappiness was because I couldn't keep the wastegate flap as closed as it needed to be (including some mechanical issues). I'd still prefer it to boost up nearly as quickly as the stocker, and it certainly a bit slower than that. So maybe the GCG one is worth the first look (for you).
    • Ok thanks 🙂 I will higly consider this. Any "known" company for a good reviews and experience to send that off? Is that CJ-motor good one? Or go straight to GCG site? I need to use VPN to even find some of those "shops" let alone access them 🙂 
    • You can literally put in as much WMI as it takes to quench the combustion totally (and then back it off a little, obviously), and it will keep making more and more power. The power comes from the cooling effect of the water (and the meth) and the extra fuel (the meth, which also has massive octane). It is effectively exactly like running E85. One might be slightly better than the other, but they are damn close. But with either you can lean on the boost or the timing (or both) waaaay more than with just petrol and the results are similar. Here's the first thing I googled for an anecdotal bit of evidence. Can't access the attachment without being a gold member, but it is there for the getting if able to, or searched up elsewise perhaps. https://www.hpacademy.com/forum/general-tuning-discussion/show/wmi-vs-e85/
×
×
  • Create New...