Trying to Decide how much power to Run

[EF Ian]

I'm trying to decide how much power to run my RB26 at in my 260Z, the engine is good for over 700hp so the only limiting factor is really how much power I can put to the ground and driveability. Max is going to be 550hp as I'd like good response and little lag.

 

I've got the appropriate chassis and suspension mods and will run a 1.5way CLSD. Only got 225 semi slicks at the moment but will be moving to 245 semi slicks once my flares are fitted.

 

 

I'll be running two boost maps, one for easy driving with something like 400hp and a high boost map with more power, 500 - 550 I was thinking but only if I can put this down.

 

 

 

 

Turbo choice will depend on how much power I want, I was planning on running HKS GT-SS turbos but if I won't be able to put 550hp to the ground I might be better limit it to 500hp and go for something slightly smaller.

 

 

 

What max power to you think I should go with? How hard is it to put down? Remember I'll run two power levels so as long as the low boost map is easy to use it does't matter if the high boost map is bit mad, but not to the point where you cant use it.

[kiwi303]

What you put down without unhooking the tyres depends on the tyres. 250Hp with LingLong 225's is mad, 500Hp with sticky DOT street racing tyres is just fine.

 

Tell us what tyres and you'll get a better response.

[EF Ian]

I'm running 225/45/16 R1R's at the moment, I'm planning on putting on flares later on and running 245/45/16's or possibly 255/45/16's if they are available, these will be either R888's, I'd run AO48R's but they only go up to 225 in 16's and I don't really want to have to change to 17's if I can help it as I prefer the look with 16's. 

[tommy260z]

The R888 is what I run. I don't run as much power as you do but the R888 has taken care of whatever traction issues I had. Good tire. Lets us know how they handle the 550hp.

[EF Ian]

Lets hope the handle 550hp, guess I won't be able to run that much in first or second gears, hopefully by third I can run full power.

 

 

What width R888's are you running?

[stony]

My original setup had 390 RWHP with stock turbos and 15PSI. it ran a best of 11.1 @ 127 MPH before I started breaking rearend parts. On the street not much could beat it. I had several scary loss of traction episodes in second and 3rd gear. In a z anything over 500 RWHP is getting to the point of useless power as not many if at all tires will stick to the road.

 

My current setup is 600+ at 18PSI and I'm running a solid rear axle with 30 inch MT streets. in this video you can see right before I shift my rpms go up fast. that's the tires breaking loose. At the track  I shift at 9500K. the shift in this video is about 7K right after boost comes on. I wouldnt dare try 9500 on the street.

 

http://youtu.be/6BvgkTuzgfs

[stony]

Other thing to consider is what have you driven before. If you have never driven anything with 700HP I wouldn't jump right to it. When I got my Z on the road 390-400 was just fine.... but after a while I got used to it and wanted more. At this point I knew how the car would react in different situations ect ect. I would have probably killed myself if I had jumped into a 700 hp turbo Z for the first time ;>

[EF Ian]

What wheel/tyre setup where you running with your original setup?

 

 

 

I never intend to run more than 550fwhp, I was just saying that my engine is built so its good for 700 - 800hp and that therefore engine strength doesn't have a deciding factor on how much power I can run, only limiting factor is traction.

 

Fastest car I have driven is probably a 600hp Evo 7, it was widebody so massive tyres and 4 wheel drive so that doesn't really count, but it could still break traction in first gear if you were pulling out on a tight corner and nailed it. After that it would be an Aston Martin GT4 and other than that my mates R33 GTS-T which is only running about 330hp so not a huge amount of driving with powerful rwd cars really, sure I've still got lots to learn.

 

 

 

The fact that I can run 400hp on the road for easy driving and still have two or three other selectable power options available is a big help.

 

Still between GT-SS turbos and R34 N1 turbos but theres not a huge difference between them, was leaning more GT-SS but I'm now thinking N1's as I'm sure they will make as much power as I can ever run.

[Xnke]

250RWHP in a Z is fast. If it was me, I'd have the boost controller setup for something stockish like 6-8 lbs, and then your "high-boost" setting.

 

You just don't need a lot of power in an early Z to make it stupid fast. 250-300RWHP is as much as I'd personally want to drive on the street, and I would want to keep it hooked up all the time. I'm only pushing around 180 (based on airflow readings from the MAF, haven't made a dyno-trip yet) and I'm traction limited in corners or on slightly damp roads. Granted, I have 9 year old 225/45/17's on the car at the moment, and I bet if they were new they might do a little better.

 

Now, in a track situation, where I am not watching for other drivers, Yeah...450HP would be a BLAST.

[stony]

Original setup had 15x10 wheels with 275x50x15 bfg dr.