|
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
Originally Posted by Z1 Performance
(Post 8808883)
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. |
when you start to get 12-12:5:1 comp is when you need to worry about higher octane fuel. might be better to use nitrous instead, nos loves high comp!
|
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.
|
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. |
Originally Posted by RudeG_v2.0
(Post 10226795)
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. |
<-- 11:1 out of stock pistons and rods :)
Use E85 and the 11:1 wont hold you back at all. |
I don't see any parts on your list that will get you to 300whp NA
|
Originally Posted by iideadeyeii
(Post 10227410)
I don't see any parts on your list that will get you to 300whp NA
|
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.
|
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.
|
Originally Posted by phunk2
(Post 10227431)
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.
|
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?
Originally Posted by Resmarted
(Post 10227540)
You bring up a good idea, but I'd personally rather have a properly put together de any day. The limitations would be sooooo much higher.
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. |
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. |
Originally Posted by phunk2
(Post 10229226)
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. Last I checked though, we're in the FI section :icon44: |
Youre right... we should create a new section for multipurpose NA/Boost builds, and move this thread there.
|
| All times are GMT -8. The time now is 07:08 AM. |
© 2026 MH Sub I, LLC dba Internet Brands