11:1 vs 8.8:1 Wiseco's on Boost?
09-19-2013, 03:32 PM
#1
11:1 vs 8.8:1 Wiseco's on Boost?
I read another thread, and Z1's post puts my mind to ease somewhat, but wanted to get some more feedback. I've never had a fully built motor, and am doing it out of maintenance requirements (failed piston rings). I will be an NA build (C8 cams, full bolt-ons), but in the future might be interest in boosting the car. I am going with 11:1 Wiseco pistons, and am curious what sort of power levels would be safe on a good 11:1 tune with either a supercharger or turbo setup? I'm expecting ~300whp NA on my DE somewhere around 7500rpm. Also, if I went FI, how much would I have to possibly lower the rev limit to account for any added stress? I'm just curious, not a boost expert.
Parts list:
Wiseco 11:1 Pistons
Piston Ring set
Wrist pins
Eagle Rods with caps
ACL Engine Bearings (Rods, Mains, Thrust)
ARP Head And Main Stud Kits
Ferrea Valve Seals
HR Headgasket
JWT Valve Spring/Shim kit
JWT C8 Cams
Rev-up oil-pump
--
JWT popcharger
Motordyne 5/16" plenum spacer
DC SS headers
Z1 60mm test pipes
Bassani 2 1/4" into 2 1/2" true dual exhaust w/ x-pipe, resonators, and mufflers
--
Osiris reflash
Parts list:
Wiseco 11:1 Pistons
Piston Ring set
Wrist pins
Eagle Rods with caps
ACL Engine Bearings (Rods, Mains, Thrust)
ARP Head And Main Stud Kits
Ferrea Valve Seals
HR Headgasket
JWT Valve Spring/Shim kit
JWT C8 Cams
Rev-up oil-pump
--
JWT popcharger
Motordyne 5/16" plenum spacer
DC SS headers
Z1 60mm test pipes
Bassani 2 1/4" into 2 1/2" true dual exhaust w/ x-pipe, resonators, and mufflers
--
Osiris reflash
The only real valid comparison is what other Z's make on that dyno as well. Otherwise, I wouldn't sweat it. The dyno is a tool, it's not omnipotent.
For compression, the difference between 8.8 and 9, is indescernible.
Yes, you can use 11:1 on a S/C car, and even a moderate turbo setup. You're talking a modest increase vs stock...nothing earth shattering. It is not "too high" - the net result will all be in the assembly and tuning, just like it is with any setup. The higher the compression, with boost, the lower your margin for error as far as tuning, but the supercharger affords you a fairly easy setup to tune in the first place. His boost threshold and overall performance is going to be somewhat limited by virtue of where he lives and the weather there. More than a guys have boosted their stock HR engines, with alot more stress (and revs) vs what this setup would be (you can only rev the S/C setups but so high). So given that a stock HR compression is 11:1, a DE setup, with proper forged internals, balanced and blueprinted as any built motor should be, there is no reason 11:1 would not work well for this setup. If it were me, I'd also consider a proper water injection system as a 'part 2' to this build...once the engine is fully broker in, tuned, and running where you're happy. I think it would give a good safety margin and a good addition for your setup, and help combat the high AIT I'm sure you get.
Max - custom compression ratios can be done too (for example, can easily do stock compression, but forged), as a custom order. Lead times are the issue as they typically take 4-6 weeks or so to make (albeit cost is the same). They can do it faster too, for an added fee. All the piston manufacturers offer this.
For compression, the difference between 8.8 and 9, is indescernible.
Yes, you can use 11:1 on a S/C car, and even a moderate turbo setup. You're talking a modest increase vs stock...nothing earth shattering. It is not "too high" - the net result will all be in the assembly and tuning, just like it is with any setup. The higher the compression, with boost, the lower your margin for error as far as tuning, but the supercharger affords you a fairly easy setup to tune in the first place. His boost threshold and overall performance is going to be somewhat limited by virtue of where he lives and the weather there. More than a guys have boosted their stock HR engines, with alot more stress (and revs) vs what this setup would be (you can only rev the S/C setups but so high). So given that a stock HR compression is 11:1, a DE setup, with proper forged internals, balanced and blueprinted as any built motor should be, there is no reason 11:1 would not work well for this setup. If it were me, I'd also consider a proper water injection system as a 'part 2' to this build...once the engine is fully broker in, tuned, and running where you're happy. I think it would give a good safety margin and a good addition for your setup, and help combat the high AIT I'm sure you get.
Max - custom compression ratios can be done too (for example, can easily do stock compression, but forged), as a custom order. Lead times are the issue as they typically take 4-6 weeks or so to make (albeit cost is the same). They can do it faster too, for an added fee. All the piston manufacturers offer this.
09-19-2013, 05:54 PM
#3
I've been noticing that Sound Performance has been doing some big power Supra builds with high compression pistons, but all of those cars are running E85 instead of pump gas. They are also running custom spec pistons intended for forced induction; not NA off the shelf pistons. If you're using OTS Wiseco NA pistons, it would probably be prudent to keep the boost levels very modest.
09-19-2013, 05:58 PM
#4
350Z-holic
iTrader: (13)
I wouldnt worry about it too much with where you're at right now.
If you supercharger or turbo down the road, you wont have to reduce your rev limiter but you'll want to keep your boost a little lower, I'd stay around 6psi to 8psi which I estimate going to give you 425 to 450whp - which is about the limit of the OEM DE block…you may have a little cushion room based off your other engine modifications.
I think the key to your engine's longevity with the aforementioned parts list plus FI will be a quality tuning device (uprev or haltech) and a very tight tune done (or verified by) someone with a good amount of experience.
If you supercharger or turbo down the road, you wont have to reduce your rev limiter but you'll want to keep your boost a little lower, I'd stay around 6psi to 8psi which I estimate going to give you 425 to 450whp - which is about the limit of the OEM DE block…you may have a little cushion room based off your other engine modifications.
I think the key to your engine's longevity with the aforementioned parts list plus FI will be a quality tuning device (uprev or haltech) and a very tight tune done (or verified by) someone with a good amount of experience.
09-20-2013, 05:07 AM
#5
I've been noticing that Sound Performance has been doing some big power Supra builds with high compression pistons, but all of those cars are running E85 instead of pump gas. They are also running custom spec pistons intended for forced induction; not NA off the shelf pistons. If you're using OTS Wiseco NA pistons, it would probably be prudent to keep the boost levels very modest.
The Supra guys are now doing the 10-10.5:1 compression pistons due to E85 and they are having great success with it.(Talking well over the 1000++whp/900wtq) If/when I have to rebuild I'll be going higher comp. myself, right now I have 9.5:1.
A Haltech should be good with its E85 capability and flex fuel.
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09-20-2013, 10:53 AM
#9
Registered User
BTW it makes more sense to me to see you do a HR swap. They make 300rwhp with bolt-ons and can handle 500hp boosted no problem. If you can find a nice clean low miles example of a HR to swap in, it sounds like a better situation to me.
09-20-2013, 12:24 PM
#10
I would check with Wiseco to make sure that 11:1 piston can handle boost. If they made the piston thinner etc for an NA application you could get issues. It's not super likely that they did remove material for weight savings or something but it's still an important fact to check. Otherwise if you have some cams and E85 go for it.
09-20-2013, 05:05 PM
#12
Cool, good to know it's a possibility in the future. I heard of the E85 idea, but just never paid attention to where it is while fueling up. Is it pretty common now-a-days?
The HR is really not much better an engine than the DE once internals start getting modified IMO. I'd rather have a block that I know is properly built, and has high quality piston rings, rod bolts, valve seals, etc. The original 2002 DE has lots of problems I've come to learn from experience, and fortunately I am confident I now know most the limitations with this engine now. VQ35HR and even the VQ37VHR barely make much more power in NA form, and I'm fairly certain the .2 liters of displacement more is the only real reason the VQ37VHR puts out an extra 10 or so WHP over the VQ35HR. I doubt any *built* HR/VHR is even much more capable than a *built* DE in boosted form, they are all just so similarly designed engines.
As far as 300whp with the aforementioned parts list, I am just hopeful mostly, but 1cockyz got 300+whp NA with similar parts, and only stage 264 BC cams (I just need to clean up the intake side somewhat), although he did port the heads. I don't think it's that unrealistic honestly.
As far as 300whp with the aforementioned parts list, I am just hopeful mostly, but 1cockyz got 300+whp NA with similar parts, and only stage 264 BC cams (I just need to clean up the intake side somewhat), although he did port the heads. I don't think it's that unrealistic honestly.
Last edited by mcarther101; 09-20-2013 at 05:06 PM.
09-23-2013, 10:11 AM
#13
Registered User
HR generation is vastly superior to the DE. As for the HR being worth a swap... for a built/boosted guy, nope.. its not worth it unless it came free/easy.
But for a NA guy... messing with a DE is a waste of time when a stock HR will always make more. Who wants 10g invested into a built NA DE when your neighbor with a 2008 350z with just I/H/E will pull away.
But for a NA guy... messing with a DE is a waste of time when a stock HR will always make more. Who wants 10g invested into a built NA DE when your neighbor with a 2008 350z with just I/H/E will pull away.
09-23-2013, 12:26 PM
#14
HR generation is vastly superior to the DE. As for the HR being worth a swap... for a built/boosted guy, nope.. its not worth it unless it came free/easy.
But for a NA guy... messing with a DE is a waste of time when a stock HR will always make more. Who wants 10g invested into a built NA DE when your neighbor with a 2008 350z with just I/H/E will pull away.
But for a NA guy... messing with a DE is a waste of time when a stock HR will always make more. Who wants 10g invested into a built NA DE when your neighbor with a 2008 350z with just I/H/E will pull away.
Last I checked though, we're in the FI section
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