Nissan 370Z Forum - compression decision

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Quote:

Originally Posted by jcosta79 (Post 2784574)

Twin Turbos

/thread

theoretically yes. but squeeze and I are looking to push our cars for more straight line power and undoubtedly a big single is much better in that aspect than two small twins.

Quote:

Originally Posted by Rid3_FaM0uS (Post 2784603)

theoretically yes. but squeeze and I are looking to push our cars for more straight line power and undoubtedly a big single is much better in that aspect than two small twins.

http://www.the370z.com/parts-sale-pr...0-shipped.html

Do it. Doooooooooooo ittttttttttttt.

I don't think we can fit 35 series turbos down there though can we chuck? maybe on the pass side but that driver side is tight as l-lell

No idea. For that price you could sell them if they don't fit and not be out any money.

I vote for 10:1 for VHR builds.

Greater efficiency in everything, better fuel mileage... drives nicer, more power out of fuel system and turbo system of choice...

Now I dont know if I would try to run 800rwhp with 10:1 on 93 octane. It could probably be done but I dont see the point in that.

But if you could deal with maybe 550-600 on pump, and 800 on E85, I see no reason to take away from the motor with lower compression. Possibly do a E98 tune for kill mode.

Quote:

Originally Posted by Rid3_FaM0uS (Post 2784603)

theoretically yes. but squeeze and I are looking to push our cars for more straight line power and undoubtedly a big single is much better in that aspect than two small twins.

Who said anything about small?

Charles I bought your stage 2 system solely for the purpose of converting the car to E85 so, just as yourself the car will remain strictly a corn burning machine. if you feel that 800whp is attainable on e85 then I feel that all I need to figure out now is my path forward turbo wise. 550-600 daily tune 800 kill tune. those are my plans for the car now

So, the only way to make big numbers would be on e85? How far could we go safely on pump gas 93?

its not that its the "only" way there are tons of high hp cars on pump gas its more so a safety issue the way I understand it. why be skating by on pump gas when you could have cushion on more less race gas. as Charles stated I dunno how much over the 600 wheel area I would want to personally push on 93 octane

Quote:

Originally Posted by elperuano (Post 2784705)

So, the only way to make big numbers would be on e85? How far could we go safely on pump gas 93?

Not nearly as far as you can go safely on E85. I know on the ZR1's you can get an extra 100+ HP if you tune for E85 vs pump gas.

I have a customer that made 799rwhp with 93 octane in his G35. Its not that we cant make big 93 numbers. Its just that... expensive engine, difficult and time consuming to rebuild it. When running the engine at its highest power, I would take the precaution of more stable fuel.

Quote:

Originally Posted by Rid3_FaM0uS (Post 2784217)

Hey guys im looking for a little bit of insight from those of you whom are a little more forged internal savvy than I. I am trying to figure out what will be my best route as far as a compression change for my block goes. I'm looking to finish my Z right at 800 whp so, I would like to pop the question of 9:1 or 10:1 I guess is as basic as I can ask it. I've been doing some forum crawling here(though now as I type this it never dawned on me to maybe check the 350z forums) and haven't seen anyone provide some real solid(per say) numbers as to when running 10:1 is no longer a good idea and bumping back to 9:1 is the best option. Also while I'm here if someone is good with compressor maps im looking to find out at what point my stage 2 GT2860RS w/ .86A/R will be maxed out psi wise on e85 at both 10:1 and 9:1(I would think in theory these compression differences would change those numbers as it will take more boost to produce equal power from the 9:1 stand point. correct me if I'm wrong though! I don't claim to know it all lol :tiphat:) thanks Z brothers! :bowdown:

I can tell you by looking at the compressor map of the GT2860RS turbos they will be out there efficiency range at 18-19 PSI after 7000 rpm's.This comes out to be 35 pounds of air a min at red line estimated 700 hp at the crank. You could probably get away with pushing them a little more but there is no point you would just be blowing hot air. There is really know way predict your power with E85 different compression ratios.

My advice to you if your keeping the GTM turbo kit I would upgrade the turbos. You can send them down to Forced Performance and upgrade your GT2860RS turbos to there HTA 2868 turbos for $700 each. This would make yours turbos similar to GTX 2867 and the compact GT3071 that I had in my kit.

The link is below.

Forced Performance Turbochargers: Turbo Upgrades

Quote:

Originally Posted by Rid3_FaM0uS (Post 2784723)

You are correct there are tons of high power cars on pump gas. Here is a graph of a GTR with a ETS turbo kit that using tubular manifold look at the 93 octane numbers. This is a very efficient turbo kit using GTX 3076R turbos. The trade of with a setup like this is more lag. The highest VQ I have ever seen or heard of was a 350z making a little more than 700whp.

http://i1311.photobucket.com/albums/...ps24c84fed.jpg

Quote:

Originally Posted by Rid3_FaM0uS (Post 2784643)

I don't think we can fit 35 series turbos down there though can we chuck? maybe on the pass side but that driver side is tight as l-lell

You can fit a 35 series turbo on our car using the T04b compact compressor housing same as the GT28 series turbos and GT3701 that GTM uses.

ohhh nice. Just a hour ago we got the motor for our 350z project back from the machine shop. We look forward to seeing what the GTX3076R's do on a VQ with our custom turbo kit... might end up having to put a pair on my 370 after the built motor goes in.

Info! I love info! Thank you squeeze! Only reason I questioned the turbo is that I would assume(once again speculation) that being that I'm running a higher octane fuel I could make more power per psi of boost so it could potentially bump the maximum hp output on the turbo up once again I only question this because in theory it makes sense. If I knew it all I wouldn't have to be here bothering you guys for answers :D. That HTA upgrade sounds like it could be the cats @ss vs spending 3k in new turbos I only question will it push 800 wheel? If not I may just ditch the TT kit and sign up for the BP kit and break even money wise if not overall better solely from the torque.