Raising The Redline On The Z

Elmo370z

A company is Canada is working on a solution to sustain high revs without running into valve floats issues. Unlike some companies we won’t be calling out, they aren’t going to put out anything until significant R&D has been done to back there claims. If it doesn’t work or they don’t go through with you probably never hear about it, if it does work I’m sure it will be blasted all across this forum. Keep in mind this is a small company so it may be a while, but 2019 should be a interesting year.

BGTV8

My concerns is with the rod bolts ... JWT will tell you that this is the weak point in a race motor above ~7800rpm

If I was running to 8000rpm on a track I'd life the rod-bolts to 40 hours.

zer099

Going with a CARR rod bolt (or equivalent) should solve that issue.

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2009 G37X | 326 AWHP | 264 AWTQ

Spooler

Then you have to worry about the crank and oil pump. The motors JWT prepared were dry sumped due to this issue and had Bryant cranks. It's not just the valve float you have to worry about.

zer099

You still going back to the price-is-right estimations we had? Is there a single recorded case of a crank in our engine braking due to over-reving? The two wet-pump/OEM style options (that I am aware of) both claim to be good up to around 8500rpms. The NISMO option (not included in the previously mentioned two) is crap. Going dry sump and custom crank seems like a lot without recorded failures to justify it. I understand precautions but innovation often trumps throwing money at something. If the stock crank can handle 8500, and you have a pump to handle 8500, and if their is a valve-train issue and it is addressed to handle 8500, why throw $8-$10k more at the engine when it can be better spent on the consumables you will need to purchase when racing? Rod bolts and better mains would be a good investment as the strain will be there, and it's cheap insurance in my opinion.

Suckerpunch alone claims their pump set-up is race proven up to 8600.

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2009 G37X | 326 AWHP | 264 AWTQ

Spooler

No one is going to post on here everything they know. Take that for what it is worth. Many secrets out there.

Rusty

Doren Racing was changing the OEM crank after every race because of breakage. It took them 2 years for them to have the rules changed to run a billet crank. Broken cranks have cost them some race wins. The OEM crank is not good for over 8K for racing.

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JARblue

Good memory - I remember Doran was having problems. But even after the rules were changed I thought they were still running into issues at times. Couldn't remember all the details

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zer099

I'm not looking for trade secrets but generalized information without ambiguity or apparent speculation is more helpful to the community I would imagine. Helping a common guy plan a build is often vastly different then a race team trying to get their car ready for a season. The whole point of this forum, I thought, was for the common enthusiasts to share information and grow. I know more vetted members can get frustrated with what may seem like ridiculous new blood questions but it's sharing information like what was learned from race teams and from our own experience that can help everyone grow; at least that's my thoughts and experience from being apart of these types of forums over the years.

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2009 G37X | 326 AWHP | 264 AWTQ

husam2012

I had my 370Z at 7900 rpm and had no issues beating on it for over a year. I needed the extra rpm as it really helps in 1/4 mile time, but other than that there's no reason to go higher on a car that's just a daily.

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Creator of the GTR TT Conversion Kit, NA Record Holder (401WHP)
Ecutek Master Tuner (VQ37, VR30, VR38, B58, S55, S58)
BTWTuning

Spooler

The search function is your friend. Use it and spend hours reading old threads. The data is out there.

Rusty

Darlen is no longer with MAM.

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浪人 - 殺し屋
"The Difficult Anytime, The Impossible By Appointment Only"
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Rusty

I have my redline set at 8,000. My shift light at 7,500. I shift at 7,500. The only time I hit 8,000 is at the end of the straight to save an up shift, down shift condition.

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浪人 - 殺し屋
"The Difficult Anytime, The Impossible By Appointment Only"
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zer099

You're presuming no search was done. Search "broken crankshaft" and you get six returns, none about breaking a crank. One from 2016 where a guy directly asks about the limits of breaking the crankshaft and the one reply he gets is more focused on HP and a slight guess at RPMs. Try "broken crank" and you get about two pages, but only one useful thread (in regards to the question), sans this thread that now shows up in that inquiry. And that one thread doesn't actually state why, how, conditions, or anything of the like; just that a when they retired an engine it typically had a broken crank, and their rev limit was 8750. Same goes for "valve float". I spent the better part of my time searching these boars and the internet before commenting in this thread. The original question in this thread was about 8000. The necro-revival of this thread was about similar, and in either cases I found it doubtful it was about season tracking the car and living its life in the 8000+ range. To enter the conversation and tell people they need to worry about there crank can seem absurd. We have no evidence you need to worry about your crank in the low 8000s with the type of use the engine is most likely going to see. Valve float, maybe. Rod bolts? According to a reputable shop it is an issue. Oil pump, for sure, we all should know that (though dry sump is not the only answer or the correct one depending on the engine's use).

The data is not always out there sometimes. Sometimes you have to wear on people's nerves to get information that they themselves might think is out there.

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2009 G37X | 326 AWHP | 264 AWTQ

BGTV8

Mate, I have been involved in motorsport for over 40 years, and I learned a long time ago that "engineering" solutions to avoid problems is a lot cheaper than engine rebuilds.

You are talking to a guy who broke 3 engines in a single season back in the 80's and they were 8-10k each in $'s of the day - maybe 2.5 times that now.

IMHO, it is well worth investing in components to eliminate sources of failure and lifing components appropriately.

That said - this is feedback from a hard-core racer - and for anyone beating on rtheir daily for 15 seconds at a time - maybe you can ignore it.

If you are regularly tracking your car and it spends more than 20 seconds per minute at WoT, then maybe you can benefit from my experience.

Doran racing and JWT (their engine builders) will both tell you that OEM cranks crack quickly at 8000+rpm and rod-bolts are a weak point in the OEM engine - do they fail - no, BUT if there is a crack - it will fail in an unpredictable time. The engineers solution is to change it once a crack shows

I'm more than happy to be ignored - but feel bound to put my hard-won knowledge out there if it can help others which I think is the purpsoe of a forum like this one.

Happy for the dissenters to dissent but am perfectly comfortable with my views.