0taku

iTrader: (5)

This summer I plan on finally keeping up with my daily before the N/A mods become irreversible.

Right now I'm simply aiming for 420-450whp on my 05' 350z.

I plan on going the Greddy 18G twin setup, but with the nice availability of E85 in my area, I want to convert for the extra reliability and power. My fuel will consist of twin-pump and FIC1100's. The tune will be done at the Uprev @ Austin. (being somewhat local is convenient)

My questions are the following.

1. Running E85 past the 400whp marker, is it required to run the fuel return system?

2. Running E85 @ 450whp as reliable as running 400whp on 93 gas?


I've done what searching I have available on this forum as well as others so I'm aware of the other modifications that need to be done such as the teflon coated hoses and etc.

My current supporting mods are the Motordyne TDX2 Dual, Kinetix SSV, and a current Uprev tune. I plan on upgrading the bottom end in the future(next year). I'd like to increase power by increments for AutoX'ing so I can compare times and such.

Thanks

Zivman

iTrader: (19)

my thoughts....
1.) you can make more power than the stock lower end can handle on pump gas. so no, I don't think 450 with E85 is any safer than running 400 on pump.

2.) running E85 requires quite a bit more fuel... the move from 400-450 requires more fuel.. I would think you would have to have a decently large fuel system or at least injectors and pump to convert to e85. a twin pump and 1100's is probably enough, but revert back to my first point

3.) sell your POS kinetix plenum and put the money towards a shortblock and then think about E85.

4.) not sure how uprev has progressed in the last few yrs, but personally I would look into running something like a haltech ems vs running a oem flashed ecu

350Z_Al

As far as his power goals go, there is absolutely nothing wrong with running uprev.

I've been running it for a year, daily driving in the summer. The driveability is great, I've had no issues at all.

My initial tune was done by a local UpRev pro tuner, made more power than my goals in just a few pulls on the dyno. Since then, I made a few changes to the car, and I created a new base map and I've been data logging and tuning it myself. I've never tuned before, but I found the UpRev to be reasonably user friendly enough that I've managed to do it myself without any complaints.

I don't know why you wouldn't want to go UpRev...

Zivman

iTrader: (19)

I just look at the stock car/ems and it isn't boosted. Things can get screwy when you convert a car to forced induction. I know when I ran the car previously off the maf, the maf isn't setup to handle the flow... so at the very least, youre looking at a maf swap to make the power I am now. it might be good up to 400 or so, I just don't know

terrasmak

iTrader: (8)

E-85 and gas doesn't seem to have much of a difference on your rods that are the serious weak long.

rcdash

iTrader: (18)

I've not heard of anyone going twin pump with a returnless system. I suppose it could be done with a custom rising rate pump to counteract boost. The jim wolf kit does this with one pump but perhaps you could do it with two. There are benefits to a returnless system but all the big power setups seem to be a return setup. High voltage to the pumps is not required and it is tried and true to achieve very high power levels.

E85 is safer because the detonation point is higher and it cools the intake charge but you will need 20-30% more fuel vs 93 octane for the same power level. With twin pumps you should be able to get to 450 whp.

Zivman

iTrader: (19)

less likely to detonate... given all other things equal. the fact still remains, 450 is a bit much on a stock block regardless of the fuel used to get there.


Personally if I had it all to do all over again. Twin turbo the car. Tune to about 390 whp/360-370-ish tq and call it a day. it's the right amount of HP for this chassis and doesn't financially marry you to the car

BluestreamDE

OldmanZ350 has a vortech sc making 577whp on a stock block for years on C16 race fuel with 100s of street pulls and drag. There is another gentleman in here with the same Vortech SC making 550 to 570whp on E85 in the forums as well, his name starys with a Ab____ on here. I believe the 400whp/400tq myth has been busted. The correct fuel octane for your setup and constant data logging and tuning are the most important things to maintain. Not saying some of the senior members on here are wrong because i do believe some moderation is needed to keep a stock motor alive with FI, but to say there is a definite limit of 400 for power would be foolish. Ive read stillen superchargers destroying VQs with low 300+hp all due to improper tuning. Also there are waay too many mechanical variables that we need to account for. These motors are over 13 years old and many have previously owned Z/Gs with lots of abuse. Just my .02

Zivman

iTrader: (19)

running a vortech isn't the same as a turbo or twin turbo. peak HP is very linear on a supercharger and tq isn't usually comparable.

yes, tuning is a major factor, but a couple supercharger setups pulling decent HP on a stock block doesn't give me any more or less comfort in running a twin turbo setup on a stock

Conway_160

iTrader: (1)

I would imagine as long as you make your boost linear like a supercharger to keep the torque down you'll be fine. But 400whp is still quick.

0taku

iTrader: (5)

That would make sense, but I'm still puzzled on whether or not it's the tune/detonation that rips the rods @ 450.

My biggest concern is staying at low boost (around 6-8) and the power increase causing concern over the connecting rod's integrity.

For example, a pretend scenario. I boost @ 7psi and achieve 410whp on 93 octane. A reasonable power for the rods to handle for now. So when I convert to E85 with the same boost, wouldn't that create more power from the octane rating?

I might be misinformed or uninformed about how E85 works. (I'm utterly mistaken if E85 only creates more power due to safely increasing boost/timing which in turn, makes more power)

If the power stays the same, under the same settings at the 93 octane, then I can imply that E85 will just help the power to be far more reliable and less prone to destruction. If that's the case, then I'm more in the clear than I expected.


I can somewhat understand, but all your examples are based on superchargers and nothing with turbochargers. It feels like this info is pretty irrelevant in a sense. Not to be offensive.

BluestreamDE

None taken. I just shared my prospective on the matter. Good luck on your build.

Zivman

iTrader: (19)

if your tune is decent, you aren't detonating, it really doesn't matter what fuel you run. e85 really allows you to run more boost....

like I posted originally, you can make more than enough power on pump gas to tear apart the bottom end. yes, e85 gives you a few added benefits, but at the end of the day it's the power levels that will eventually do you in.

I guess it goes back to the old question, if you are looking at 400hp, why not 500? why not 900?

Have you driven the car at 400 already and decided it needed another 50? You are coming from a N/A setup that might be 250 hp on a good day. at 400, I am sure the HP isn't the limiting factor in how fast it makes it down or around the track.

I've spent STUPID money on boosting my car and I can tell you 400 hp is 99.99999% as much fun as the 550 hp my car made on its last tune, and it will be 9.9999999% as much fun as the 550-600 hp it will make on its upcoming tune... the kicker is, 400 can be achieved with a fraction of the cost and headaches.

Build a good driving, relatively reliable car that makes decent power. And that, IMHO is about 390 whp and 350-375 tq on a stock block.

0taku

iTrader: (5)

That's a really good point, and I'm going to visit the shop to see what the pricing will be on upgrading the internals as well.

I can still keep the boost low because I'd rather transition into the power rather just ruining myself.

My budget isn't too constricting, I was keeping extra money on the side in case something goes wrong but if the price is right at the shop I should be able to prevent more issues in the future.

Zivman

iTrader: (19)

You have to look at it like opening Pandora's box rather than prevention. There are no guarantees..

rcdash

iTrader: (18)

Really good posts zivman, agree on all. i've got 800 whp on e85 but I only really feel that power in 4th and 5th gear. It's detuned for gears 1-3 for traction, esp with VDC on (had a few scares with it off) and 400 whp is going to feel nearly the same. A 3rd gear pull at 400 whp is exhilarating. With higher power you have that same level of acceleration in the higher gears. Enjoy the 400 whp and save yourself a bundle! ;-) It's a blast and addictive, but it's got to be money you can throw away... Besides which, your chances of living longer will be higher! If I ever wipe out at WOT in 5th gear, it's all over. It takes just a few seconds to top 160 mph!

0taku

iTrader: (5)

You and Zivman bring up very valid points.

rcdash, did you upgrade your sleeves or are you running stock sleeves? If you're running stock, how many miles have you been running that kind of power?

Zivman

iTrader: (19)

stock sleeves will be fine for 700+. From what I have seen over the yrs, sleeving this motor adds unneeded complexity to a build. Once you upgrade the rods and pistons to hold the power, main focus is keeping the heads on. having sleeves can make this challenging

rcdash

iTrader: (18)

^ agree. I did not sleeve but I knew I would be limiting power to what 1300 cc injectors on E85 could put out. I also realize that my cylinders might end up out of round eventually. When the motor fails, it fails. Will decide what to do then. So far so good.

Few shops are able to sleeve without subsequent HG failure due to a sleeve dropping. If the point of the sleeve is to increase reliability for high hp levels, then statistics would seem to indicate that as whole, the VQ motor building industry has failed. No offense to the few shops that can actually do this reliably 100% of the time (Darton themselves not being one of them).

venture210

From what I've seen in my personal experiences, forged rods and "looser" bearing clearances alone increase the power limit the most. Stock pistons are suprisingly strong especially on e85!