HarrisRacing

And here is the 8375 .91 AR twin scroll at 21psi (dropping to 17) VS. the 8374 EFR IWG .92 AR twin scroll turbo which can hold 21 psi to my redline. As you can see they are almost IDENTICAL in spool and power with exception of the EFR being able to support the extra flow (74 lbs / min) on the top end and carrying 21 psi all the way to redline of 8500 rpms. Pretty much projected to make 50 whp more from 7500-8500 from the little extra push from the compressor. Again these are pumpgas projections on low boost (21 psi max). On my stroker motor I DEFINITELY give the nod to the 8374 EFR on .92. On a 2.6L, however, it didn't make this much difference! Shame of it all is that if the 8375 was offered with the same turbine as the 8374EFR, I think the 8375 (cast) would matche the 8374 EFR almost identically at 18 psi (or lower) on 2.6L. 8375 results from match-bot are in post above. 2.75L 8374 EFR .92 IWG T4 divided matchbot results: low rpm high rpm I know I'm replying to myself, but I still think I'm trying to offer solutions for some of the stroker guys out there.

I'm going for a very similar build. I guess I'm trying to figure out what cams and additional stroke do to VE tables for engines and I'm having trouble finding it all.

I reverse engineered some 2.6L VE numbers and came up with the following: RPM - VE 3000 - 72 3500 - 72 4000 - 80 4500 - 100 5000 - 111 5500 - 117 6000 - 120 6500 - 121 7000 - 121 7500 - 118 8000 - 115 These numbers support some dynos that prove that the 8375 turbo is maxxed out at ~68 lbs/min airflow. It also supports the boost threshold of such setups. I am assuming this setup had CAMS. If I use these VE numbers, my estimated 2.75L HP dyno comes up as attached on pump gas and 21 psi boost by 4k rpms and dropping to 18-17 range above 7500 on the 8375 and .91 housing. Feel free to play with my Match-bots: low rpms high rpms

Do you mind telling me exactly what the setup you had previously was? I'm trying to find solid VE data for the RB engines and I'd like to use dynos (like yours) to determine where we are in terms of VE and turbo calcs and how this is applied. Using the defaults in Match-bot seems to make engines seem more responsive than they are in real life. For your car and the first dyno posted, I came up with the following numbers so far: I simply can't get match-bot to work with your recorded boost, rpm, and power levels any other way than with these tweaked VE numbers, but they sure are close with these VE numbers! stretching from 72 out to 121 seems outlandish..but it makes the data fit and supports the maximum supported airflow of 68 lbs/min that this turbo is advertised at. I am assuming your engine had cams previously? RPM - VE 3000 - 72 3500 - 72 4000 - 80 4500 - 100 5000 - 111 5500 - 117 6000 - 120 6500 - 121 7000 - 121 7500 - 118 8000 - 115 I do not know the effect that increasing stroke has on existing VE, but I sure would like to know. I'm hoping it increases at low rpms...because if not, Match-bot doesn't think much changes on the bottom end as far as boost threshold goes with these numbers. If you play with it, you will see that going up from 2.6L to 2.75L makes VERY little difference other than overall power. seems that VE drives a ton turbocharged HP calculations. Sorry for attacking your thread with technical jargon, but I am trying to help you decide how much power you'll get out of the 8375. Sometimes going UP in displacement hurts efficienies, and resulting power. It may be better matched to a 2.6 or 2.75 than a 2.9

Don't know how I missed this thread before, but I'm glad it got bumped...it's been a great read. Right now I'm in deep contemplation of single turbo for my 2.75L stroker (if you want to call it that). I took the liberty of finding some dynos from both Joey and Simon's cars early on at lower boost levels. Albeit both on E85, they are both still at around 20 psi. Joey stated that his 8375 was pretty much out of breath on top and I used the dyno that is missing the 24psi midrange in this comparison (for fairness). I assumed his was standard cast wheel and I also found that his was the .91 housing and I saw where Geoff at full race recommended 1.00 for more power. For the money, I just don't think this turbo can be beat for a nice powerband and while Simon has made STUPID big numbers I think on a 2.6L and for $600 US, this is looking like a strong candidate for a pumpgas turbo. Of course I am not taking the EFR 8374 ($$$$$$$) into comparison yet. Anyway hope this helps put things into perspective for others looking for information. If anyone finds a dyno of a low boost stroker build with the 8375 (cast) or 6266, let me know...I'd love to add them. Patrick

Here is the latest model that I have for an 8374 EFR in the match-bot software. I'm using RPM, VE, Boost, calc'd HP as follows: 3200 rpm, 90%, 15 psi, 254HP 3500 rpm, 90%, 21 psi, 313HP 4500 rpm, 110%, 21 psi, 444HP 6000 rpm, 110%, 21 psi, 561 HP 7500 rpm, 105%, 21 psi, 623 HP 8500 rpm, 100%, 21 psi, 613 HP I guess the question is, if you plot this in excel, does it look like a good graph. Match-bot shows that the turbine and the compressor on this engine (90% VE at 3200 rpm) should make the 15 psi boost no problem BUT Theory and practice are only the same in theory...not in practice.

Thanks and I totally agree. I must be using some bad VE numbers. More than likely I am too high on the VE at the low rpms and too low on the high rpms. I'm trying to reverse engineer other people's graphs to see what to expect for VE. The calcs in match-bot display HP in flywheel HP, and NONE of my calcs come close to some of the numbers that others have hit on pumpgas. Very curious to see what Geoff or others would use for VE on an RB26DETT that's stroked and ported.

Green line is power. Power peaks all the way near 7500. Even if the power stays over 600 above this, there is still a reason to stretch the powerband out and have the tune in place for the revs. I am curious if the engines can do it is all...maybe this is too much to ask for the stock bottom end?

Effing-A that is some good power!!! All this on a STOCK bottom?!?! As a mechanical engineer I LOVE reading data and sorting through turbo selection and compressor maps...none of which Precision provide...but DAMN the numbers don't lie!!! I guess they let their powerbands do the talking. This turbo would be sick on my stroker motor. I have to ask, why do so many people keep the revs down on their dynos? Am I crazy in thinking mine will go 8-8500 no problem?

I am nearing completion of my build and need to decide on a turbo. I have narrowed it to a few choices and would like some feedback on my selection and math (because garrett boost advisor and BW match-bot programs slightly differ in recommendations). Engine is the following: BC stroker on stock N1 bores = 2.75L 9:1 CR SS BC valves oversized +0.5mm intake and exhaust Ported cylinder head (nice smooth setup...nothing crazy) Tomei Poncam A's Divided T4 tubular manifold Haltech Platinum PnP ECU 850cc injectors Tomei oil pump Greddy Sump Side drains for pan (2x -10 lines to breather, etc). Car is R32 GTR and is street car with plans to track on occasion. Pump gas most likely all I will run which is "93 octane" here (98 RON?) BW 8374 EFR 1.05 AR Match bot shows Boost comes on strong at 3200, and 532 HP at 7500 rpms BW 8374 S300SX .91AR Again extremely similar numbers to the 8374 EFR with exception of the ability of the compressor to come on earlier?! With the .91 AR housing and the shallower compressor map, this should make 16 psi boost at 3000 rpms. Technically this should be a better combo for 532 BHP? Am I missing something between these plots because I was assuming the EFR would have made more HP on top end? BW EFR 9180 1.05 AR 15 psi boost at 3800 rpms. At 20 psi now a 50 HP gain making 580 BHP. (Next post will be Garrett Turbos).

I'm in on this as well. Pulsed out fuel pumps! Sweet! I am still building my engine and i just started going through haltech software for mine. What kind of IO are you using for boost control and which solenoid? Also what kind of IO board are you using for the fuel pump pulsed outs? I'm quickly realizing the power of this ecu!

I asked this question in my build thread and didn't get a reply. Can you elaborate on how much power/torque we are taking about as a safe limit? I rally don't like doing work twice. How's the R34 box swap as far as power ratings? Sorry to hijack your thread but I felt it applies. Edit I see you answered 400wkw on previous page. What about the r34 box? And what about the front diff?

Lol yeah the -7s will be sold off! It will be single turbo now if for nothing else but to clean up the engine bay. Likely only a 6266 although 6466 and 5862 crossed my mind. I saw simonr32's track videos and realized how lively a 6266 is on his stock bottom end and got a serious chubby for that setup! Ahh the slippery slope of GTR fixing. And that Hypertune V2 sure would clean up the engine bay some more! (Assuming someone would trade one of my kids for it!)

I have climate control I have rear wiper Stereo and all component s were missing when I got the car I really don't know which diff (or diffs) are in the car right now but the factory service manual mentions nothing of a viscous diff in front or rear of GTR I have ABS Brakes are gold calipers Sumitumo up front (brembo?) And grey calipers in rear I'll check mirrors next time at the shop Turbo part numbers are: EA0138J 14411-24UD4 466071-6D

I have the same MZG which doesn't seem to decode per writeups. I do have the rear wiper. I do have climate control No clue on differential yet. Can anyone help?

Changed the cut a bit. After looking inside the pan some more I didn't like the horizontal dividers. I made a decision to add some drilled holes at the bottom of the slopes on one side and to completely cut the other side off. I also added a small hole in front in the incident that air gets trapped up there. I also am not going to remove the diff for welding and will instruct the welder to take his time around the diff and seals. Also installed the tomei oil pump (as delivered with both springs) and N1 water pump. I was surprised that there is no gasket there nor on the rear main seal...interesting. I'm also adding the 2x -10 fittings as simonr32 has. I marked and cleaned the spots. Can't wait until the head comes back so I can throw it on the engine!

Also, is it necessary to remove the differential prior to welding the pan? Are there any seals to hurt or replace in the process? I would figure if the seals can handle the heat, leaving the diff IN would reduce warpage. I also have the old block to bolt the pan to when we weld it.

Installed all new nissan cv boot kits on front axles last night while I had them out on the bench then moved to the greddy oil pan extension mods. I saw another thread where a guy did something similar to this but after looking at it I may add some more holes (pictured) since the reinforcing ribs might hurt draining where the factory 3 sump extensions are. What do you guys think?

Well you got me paranoid so I added some copper crush washers under the squirters today. Just that extra bit of insurance. Note for future builders , clearance more than my pictures just in case

Thanks Bnr32-013413

If you look hard enough for Ebay manifold Reviews you will find a thread about some Madzaspeed 3 guys who are using manifolds that look JUST like this that are made by XS-power. They are the GEN 3 manifolds from XS-power and the thread has guys who have been testing the XS-power gen1-3 manifolds. It's strange that this one seems to be made by this TOG shop and looks JUST like the geometry of the XS-power RB26dett T4 divided manifold, but is welded steam pipe. This is what XS-power has done with their gen3 Mazdaspeed manifold. Another note (not that I'm trying so hard to justify "china" manifolds), but Aaron with Driftmotion.com over here in the states has been using China manifolds for YEARS on his budget Supra turbo kits. He offers REAL Garrett turbos, but he has said that some of the China manifold brands have had some amazingly reliable results on their cars. He likes the wastegates, BOV's, and Manifolds and says he doesn't stock anything that doesn't work. He did say some of them are clearly junk, while other brands are tried and true. He did steer me to some specific brands to look for since he doesn't sell manifolds for RB engines yet and wanted me to send him specific pictures of what I find. Guinea pig! Either way I hope it drives The Full-Race or other similar brands pricing back down into reality. It sure is hard to justify spend more on a "dumb iron" piece of pipe than the actual turbo (which has decades of engineering research, and moving parts!). Found it. Post number 654 http://www.mazdaspeedforums.org/forum/f10/xs-power-turbo-manifold-here-install-pics-154973/index17.html#post2767493

Damn...that manifold looks nice!

I'm in the USA and I'm looking for a DRIVER's (RIGHT when sitting in car) Side R32 GT-R seatbelt retainer. This is the part that the seat belt clips into. It is located near the center tunnel and has the button to release the seat belt from it. Mine is broken and I'd like to replace before I finish my build. Please tell me what you have and price shipped to Lafayette, LA 70508. USA. Thanks Patrick

Oh...I also got approved for my personal plate. It's the first one I have had. I tried every spelling of GODZILLA or GOJIRA possible. They were ALL taken except for what I got "GODZYLA". I felt it appropriate.

Alright big updates. Machine shop found the coolant cracks in the block from the head stud holes to the water jacket. LOTS of them. Scratched the idea of boring and using this block and purchased a NEW N1 block...and wow is it gorgeous for the first time in my life to have 100% all new parts to go together! I ported the head, found LOTS of play in the valve guides including ONE broken one! Here's the new list of parts that I HAVE PURCHASED and RECEIVED: BC stroker kit w/ sportsman rods ARP main studs ARP head studs ARP flywheel bolts Ported the head BC +0.5mm OS SS valves for intake and exhaust (do not need to bore seats for these) BC single valve spring and titanium retainers and new BC locks BC phosphor-bronze valve guides Tomei oil pump Fluidampr harmonic balancer Tomei Poncams A Haltech Platinum PnP Deatschwerks 800cc injectors Deatschwerks Fuel Pump DW300 Mine's valve cover breathers. Cylinder head is at RAWBrokerage getting final port/polish and assembly now. BC completee gasket kit N1 water pump HKS timing belt Z1 motorsports new silicone coolant lines (to/from Radiator) New pilot bushing New Throwout bearing Tomei block oil restricter Greddy Oil pan extension OEM thermostat Hicas Lockout (Whiteline racing) Exedy Hyper Single VF clutch kit (likely won't work for my new power level) Nismo clutch line New NISMO floor mats (lol whatever I wanted them!) Splitfire coils New CV boots Megan Racing Subframe bushings Nismo clutch fork pivot Nismo shifter bushing Autobahn 88 silicone hose set I measured and assembled the entire shortblock last weekend. BC stroker crank, Sportsman Rods (good for a mere 1,200 HP), and CP pistons. The CP pistons gave issue with clearance at the oil squirters. Seems they move the wrist pin in the piston design and don't increase the relief at the oil squirter. I took some measurements and started the grind / clearance of the pistons. Don't worry about the comparison picture, I disassembled all the rod/pistons and cleaned everything after clearance. Actually I pulled all the remaining ones apart once I had the measurements down. ARP main studs. ACL "Race" bearings. Installed Tomei oil restricter Also getting all the valve covers powdercoated "2009 Ford F-150 Amber Gold Metallic". Should look pretty wild. Then I am pretty much decided on single. PT 6262 or another shop's own 6262 build using the new Garrett GTX3582R 11 blade 62mm compressor on the same 62mm turbine rear as the Precision uses. Not sure about manifolds yet. Looking at .84 divided. They say these turbos have incredible response. Doubt I'l spend the money on the BB option. As SimonR32 has done, I will be adding the breathing holes to my oilpan when I get the Greddy sump welded on. This forum is a WEALTH of information! I will be running track days on the car and driving around for spirited fun on the weekends. I won a championship in the GT2 class in 2010 in my Toyota MR2 Turbo (which I recently sold, as well as my MKIV Supra TT 6 speed Hardtop). Looking good so far!!