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I'm going to have to upgrade my fuel pump from a DW300. DW400 looks to meet my needs (and just above). Pretty sure I have to modify my hanger anyway, so the question is, dual DW300 or go with a single DW400?
Those 97mm 0.040 Cometic VQ37VHR gaskets- I think I'm okay to use them even though I'm only going to be 96mm bore. I assume I'll end up getting the block decked or the heads, or both, so I'm fine with the additional thickness. Just curious on opinions here.
I assume stock main caps are fine? At what point do people justify billet?
Block guards; seems to me they would restrict coolant flow with the tiny holes. Do people open up the holes around the coolant holes in the gasket? Surely that wouldn't compromise the structural rigidity?
Yeah I didn't want to say it, but Renfro is totally right. If you were pushing 30-40psi 8.8 might be a good option, but at 15psi it'll barely touch the sides (so to speak). Z1 really needs to update/expand their info. Same with CZP.
N350X is awesome. If you're going to go that route, consider wiring in a few more sensors to your ECU (like oil pressure at a minimum) and installing a WB that uses CAN interface.
Thanks. Yea; I'm gonna have to research this some more. Maybe go with a Turbo kit instead. It looks like you really need 20psi or more to be efficient at 8.8CR... I am kinda bummed Z1 got me confused on this. They should be more specifc; i.e. 8.8 for High boost pressure F.I lol
I found this CR/boost pressure chart on some site I was reading. Seems to clear things up for me.
I'm going to have to upgrade my fuel pump from a DW300. DW400 looks to meet my needs (and just above). Pretty sure I have to modify my hanger anyway, so the question is, dual DW300 or go with a single DW400?
Those 97mm 0.040 Cometic VQ37VHR gaskets- I think I'm okay to use them even though I'm only going to be 96mm bore. I assume I'll end up getting the block decked or the heads, or both, so I'm fine with the additional thickness. Just curious on opinions here.
I assume stock main caps are fine? At what point do people justify billet?
Block guards; seems to me they would restrict coolant flow with the tiny holes. Do people open up the holes around the coolant holes in the gasket? Surely that wouldn't compromise the structural rigidity?
1. What injectors are you running? I know a SC setup requires more fuel, but I'd imagine a single 400 would support what the HKS can put out. I'm currently on a single walbro 450 with ID1050X injectors on a return system making a bit over 600whp with a turbo.
2. I'd be somewhat concerned about not having a matching gasket bore. I don't have much to reference, but my opinion is the closer to the bore the better.
3. Shouldn't have an issue with main caps, but consider getting the dynosty billet girdle (assuming DE engine, I might have missed details about your build above).
4. Depends on overall power goals. I'm on the fence about block guards, not necessarily with the coolant flow through the guard, but that the guard removes full coolant contact at the hottest, upper most portion of the cylinder and combustion chamber. Again, I'm sure it's necessary once we start getting above 700-750whp, but I've heard of open deck setups going 800+ as well. I stayed open deck, as I never intend to go above 650ish whp.
Ugg... I heard back from Z1 they confirmed 8.8CR will not work for my application. So I have order the 11.0CR pistons pull the bottom end back apart and swap out the pistons. I won't be too bad really; I just need to remove cams, rear timing chain cover, Cylinder heads and take apart the bottom end. I just hate doing stuff twice... At this rate I'm gonna hold off on SC upgrade for now. I'm just going to finish engine rebuild, reinstall it. Upgrade exhaust headers and injectors, plus any other minor jobs I can knock out while the engine is out. Install it. Verify everything works/get a base tune. Then in the future; probably next fall install the SC upgrade. That way I can drive/play with it a little during the summer 🫡
I'm going to have to upgrade my fuel pump from a DW300. DW400 looks to meet my needs (and just above). Pretty sure I have to modify my hanger anyway, so the question is, dual DW300 or go with a single DW400?
Those 97mm 0.040 Cometic VQ37VHR gaskets- I think I'm okay to use them even though I'm only going to be 96mm bore. I assume I'll end up getting the block decked or the heads, or both, so I'm fine with the additional thickness. Just curious on opinions here.
I assume stock main caps are fine? At what point do people justify billet?
Block guards; seems to me they would restrict coolant flow with the tiny holes. Do people open up the holes around the coolant holes in the gasket? Surely that wouldn't compromise the structural rigidity?
I'm running the Walbro 485 (450lph) for reference if that helps, no issues so far with the ID 1050Xs and E85 with the 100mm pulley.
1. What injectors are you running? I know a SC setup requires more fuel, but I'd imagine a single 400 would support what the HKS can put out. I'm currently on a single walbro 450 with ID1050X injectors on a return system making a bit over 600whp with a turbo.
2. I'd be somewhat concerned about not having a matching gasket bore. I don't have much to reference, but my opinion is the closer to the bore the better.
3. Shouldn't have an issue with main caps, but consider getting the dynosty billet girdle (assuming DE engine, I might have missed details about your build above).
4. Depends on overall power goals. I'm on the fence about block guards, not necessarily with the coolant flow through the guard, but that the guard removes full coolant contact at the hottest, upper most portion of the cylinder and combustion chamber. Again, I'm sure it's necessary once we start getting above 700-750whp, but I've heard of open deck setups going 800+ as well. I stayed open deck, as I never intend to go above 650ish whp.
1. Thanks guys; I should've been clearer. The DW400 alone will definitely be enough. The question was more do i just add another DW300 (cheaper) and run a dual pump setup (because I have to mod the hanger anyway), or just retire the current DW300 and swap in the DW400 instead.
I think it's probably a redundant question as two pumps are more complicated and probably twice as noisy so if you don't need to, stick with one.
2. I've read 1mm is fine and allows for some squish but I'd be keen to hear some more on this. I'll be chatting to a builder about it anyway.
3. Dynosty girdle is already on the shopping list!
4. It sure seems unnecessary for my power goals, but like you I'm trying to over-engineer the build for maximum strength and potentially more power down the line (though I doubt ever 800+). If it's not a detriment to the engine (which it might be) then because I've already got it I'll add it as insurance. But yeah, keen to know others experience. Again, I'll chat to the builder about this too
Just gonna say Soho > Z1 for all things boost.
From my discussions with @bealljk on gas a AEM340 and 1050s should be enough for this blower.
I do not think its wise to push power past what this blower can handle, if more is desired then it's Vortech or turbo.
@DarkZ03 I'll continue to use E85, so with DW's calculator it seemed pretty clear I'd need at least a 400LPH pump. That wasn't the question though, it was more around throwing a second smaller pump to meet the requirements, or go with a larger single.
Not sure I got your last point? No plans to push the 8555 beyond its capabilities, but I want to build the engine to be capable of much more in case I decide to change FI system in future (ie. Vortech/Turbo).
@DarkZ03 I'll continue to use E85, so with DW's calculator it seemed pretty clear I'd need at least a 400LPH pump. That wasn't the question though, it was more around throwing a second smaller pump to meet the requirements, or go with a larger single.
Not sure I got your last point? No plans to push the 8555 beyond its capabilities, but I want to build the engine to be capable of much more in case I decide to change FI system in future (ie. Vortech/Turbo).
Oh yeah, for E85 then you do need more.
I was skimming the thread and didn't catch much more than 700-800 hp and thought it would be on the same blower for some reason lol.
I fully understand wanting to over build as that is what I want and I know I don't want more power, just want to be able to push it without fear.
I don't know if there is a benefit to one big vs two small, but part of me would say two is ok with aftermarket hangers and one with stock one.
Love the build, planning on going this route in the near future after getting some other supporting mods done. A few questions if anyone can confirm: is 255LPH + fuel pump good for under 400whp/wtq? I was considering the Nismo High Volume fuel pump assembly (276LPH) or the AEM fuel pump unit. How much louder are these vs stock? Is the FMIC on this kit half the size of the front support? And would the 100mm pulley build boost sooner in the RPMs vs the 110mm pulley? I was told it would not matter but I know the Vortech guys who run smaller pulleys experience power coming on sooner. It's going to be interesting to see how the Z1 Rotrex kit in development for the DE will compare to the HKS kit. Thanks!
The intercooler is quite big, what do you mean by half the size of the core?
pretty sure most Centrifugal blowers operate on RPM so it should always make power linear to RPM.
After the issues I've had with their products, I could never spend money on a kit from them, HKS (or any Japanese company) have way better QC than Z1.
Oh, and also i was recommended to get the AEM 340, lets you have overhead in case E85 is desired.
It's a very decent sized intercooler, yeah. Half of it is obstructed by the crash bar but it's not completely lost efficiency- plenty of surface area to dissipate heat.
255LPH is fine for 91-98 but why restrict yourself for such a small increase in cost. I went with a DW300 (340LPH) to give myself room with E85. I'm going to have to upsize for my build though.
The 100mm is always spinning at a higher RPM relative to the 110mm but at low RPMs it would be negligible. I assume it will also reach positive pressure marginally quicker than the 110mm but until we get someone that installs and tunes on both we'll never know.
I mean I'm curious to see how Z1's kit performs too, but like Dark said, HKS are better known for quality.
Thanks for replies! Sorry for the confusion, in regards to the intercooler it seem that the V1 came with an intercooler half the length that is now offered with the V2. I don’t know that I would utilize E85 or push anything above 400wtq/whp so the other options appealed to me more. From what I have read in the BRZ forums, the HKS rep said that running the smaller pulley with restrictor would bump low/mid end torque without overshooting the max PSI. This seems to be in line with what we see on the HKS Dino graph posted for this kit comparing the 100 and 110mm pulleys. The 100mm definitely makes more power earlier but like stated, we would have to have someone dyno it to see exactly how big that difference is. HKS has been pretty consistent with any numbers they throw out though. I agree HKS would definitely have better quality and finish which is one of the reasons I wanted this kit.
So you want to know that the difference between the two kits are?
I wouldn't even consider the V1 kit, the highest independent Dyno I've seen for that kit is 340whp on a sprayed IC, and it "essentially" costs the same.
As we can see here in this thread and in Timboj's YT this kit can do that without issues, and go up from there if desired.
Do you mean the GT2 kit with the 7040 blower? (12001-AN009). Or was there a V1 to the Pro-Kit GT V2 (12001-AN008)?
The former does have a smaller IC, but also the a smaller, less efficient blower.
Stick with the GT V2. I'm very happy with where I landed re 100mm with modded restrictor. Still haven't gone over 10.5psi and I've thrashed it many a time.
No no I know the V2 kit is superior in every way, I was simply wondering if they had changed the IC length. I feel that I will be going with the 100mm + restrictor simply for the better response without pushing the engine too hard. Quick question on the setup, now pushing 400wtq should the brembos be sufficient for spirited drive or do people go with akebonos instead? Thanks!
Ha now that's another conversation altogether. I'm still on the Brembos, with Ferodo DS2500, braided lines and high temp fluid, and I've thought they're a bit weak on track. However there are experienced drivers out there that run full seasons on the stock Brembos so it might just be my skill level...
Anyway quick update from me as it's been a while. I've recently added a third a final extension harness to my G4X to add some more IO in general but mainly to install a temp sensor for my traction oil.
I personally think the G4X is the best value aftermarket ECU for the 350Z (DE/Revup)- it's plug n play, has a zillion IO options, the functionality hardware and software are first rate and well supported.. BUT the housing for the N350X was not well thought out. Most of their PnP ECUs don't even come with a housing so on face value it's great (solid cast aluminium) but it has to be drilled/ground to make openings for the harnesses. That wouldn't be a problem if you could disconnect the f*****g housing from the base with the circuit boards...
It doesn't matter what precautions I took, I always ended up with metal filings through the circuit boards. No amount of vacuuming and compressed air made me feel comfortable on clean up. On top of that, reinstalling everything is ridiculously fiddly. One of the least enjoyable jobs I've had working on my car, period.
You can see here I cut the cables short (they're 2.5 metres long normally) and installed my own DTM connectors, otherwise when you wire anything in your ECU is permanently wired into the vehicle...
I installed the temp sensor on the return right before the traction oil bottle. I'd have preferred to install it just before the inlet of the SC but this was magnitudes easier for the install (also for the harness) and I can't imagine the delta between here and the feed is that different. Regardless, this is about establishing a base line of my readings from my current setup (boost, power etc) to compare against once the engine is built and I'm pushing higher boost.
Adding it to the ECU was a breeze and data logging is underway.
I should've lubed the left hose like I did the right, but wotevs...
I think that's just the DS2500, I think the Brembos require more pad than that if you are tracking hard.
On the street Brembos are just fine with decent pads.
@Timboj how is the car running right now?
Is there anything you regret or would do differently?
Interesting. I'll look into some alternatives track alternatives, cheers.
Mate, the kit is awesome, I'm really happy with how it drives and general behaviour. The tune is always a work in progress but that's just because I'm OCD about cold start, idle etc..
The only thing I would do differently was start with the unrestricted 110mm and not waste my time/money on having to retune after opening up the restrictor (interesting as it was for comparison).
I'd love for someone to try the unrestricted 100mm on a stock bottom end but I just wasn't game.
The only thing I really need to do rn is install that duct in my bumper to get air through the oil cooler. Haven't had a lot of time for the last few months.
In terms of what happens next... I reached out to HKS for comment on whether a 90 or 95mm pulley would overspin the blower. They said they hadn't tested so couldn't say, but all I wanted was the equation...
Also, I'm leaning pretty heavily into 12:1 CR pistons though I've still got time to pull the trigger
03-20-2023, 03:32 PM
