Guys as im from the UK, and looking to go FI i just wanted to know why in the states you guys think 400RWHP is around the safe limit on the stock bottom end, and have cars running for 10,000's of miles at this power. All the tuners/ engine builders in the UK and the main UK APS dealer say 400 BHP @ flywheel (330rwhp ish??) is the limit?

Also in the UK the crap fuel over here is 95+ RON and my car only runs on 99RON shell Vpower which is better than what the states has ? Would that not mean we would be safer when boosted?

Last question. Is the US RON number the same as the UK?

I can get BP102 Ron pump fuel just up the road from my house. If the ron scale is the same is this not far off you race fuel?

Thanks guys.

 

we can run at the pump here 91, so u should be fine running 95+, and safe over there w/ that fuel would prob be around 435WHP

 

Our fuel is rated RON+MON/2. Ranges from 91-94 octane across the country. I think your shops are conservative with what is deemed safe for a stock block, but that generally, is a good policy.

EDIT: I believe your 95 RON is comparable to our 91 R+M/2.

 

We say 400whp is a safe # over here in the US, because we have the BEST tuners

 

As it looks that number keeps going up and up!! hahaha i know a couple guys way up in the 450+ club that are still going strong!

 

As they already mentioned, US uses r+m/2 rating and most places are 91-93. The reality is gas is not a stock VQ35DE's limiting factor, the rods are. (This is assuming the car is tuned appropriately)

 

Thanks for the info on the fuels guys.

 

In US they use the AKI anti-knock index which is what the guys already stated, and in Europe and Middle East RON (Research Octane Number) is used

89 AKI = 92 RON
91 AKI = 95-96 RON
93 AKI = 98 RON

I Took this from 2009 Nissan GT-R Owner Manual:

Unleaded gasoline with an octane rating of at least 93 AKI (RON 98)*1

*1: Use unleaded premium gasoline with an octane rating of at least 93 AKI (Anti- Knock Index) number (Research octane number 98) to maximize vehicle performance. If 93 AKI number (Research octane number 98) premium gasoline is not available, you may use unleaded premium gasoline with an octane rating of at least 91 AKI number (Research octane number 96), but you may notice a decrease in performance.

 

20,000+ miles here on my stockblock setup. Daily driven with either 344whp or 405whp. Your tuners are just being alot more conservative.

 

Net shark thats great for posting up!

 

Who are you looking at geting it tuned with? It might just be that they haven't got much experience with the Z, and there just covering there a$$.

 

Tuning would be done by DS Automotive the UK APS dealer of Dan Turner of AME.

Im looking at going SC as the torque of a turbo would be great but wold make me worrie about the engine life.

If i was to get the turbo tuned to around 330whp/lbft that is on the safe side is it not?

 

you could accomplish that goal with a turbo setup very easily. 6 psi made 344 whp on my car, which was basically just wastegate pressure.

 

Over 50,000 miles on boost here with a stock block.

 

Dave @ Function FTW

 

Just a little off topic What are you paying for a gallon of premium in the UK?

 

Full tank costs me £80 from empty. (99ron vpower!!) Ouch! lol.

 

Yep but only for about 10,000 of those miles.

 

At todays rate that would equate to a $140 fill up GULP.....

And I was griping at a 65 dollar fillup.

One of the other forums I belong to is the Insightcentral.net, I wish I had kept my insight, 60+ MPG on 87 octane would have saved be a bundle this last summer with a 140 mile per day commute...

 

OP:

First thing i worked out, wayyyy back in my civic owners day, is that USA Hp numbers are inflated. I did tests, same setups, different HP outputs, same 1/4mile times.

Dyno Dynamics confirmed to me that they configure there US dynos to read differently (higher) then there other dynos.. This is mainly because the US guys grew up with dynos that output very optimistic numbers (some say, flywheel horsepower), and the only way to compete was to try and emulate the numbers as much as possible. No shops wants to be sending customers home with 100 less hp then the guy next door! THese days, things are becoming more relaxed in the tuner community though. People are embracing dyno dynamics for the there effectiveness, and are coming to terms with 'heartbreaker' results. Even though these heartbreaker results are still overinflated.

The fuel issue has already been covered. UK uses the same rating system (RON) as Australia. http://www.torquecars.com/articles/f...ne-ratings.php

We used to have 100octane vpower (10% ethonal) here, but not anymore. 98ROn is the best pump, equiv to amercan 94~.

My advice is to tune to around 360-380rwhp and u will be good to go. Thats around 8psi. 8psi is sweet. Keep timing conservative and u will be reliable as!