LEK

^^ i think he's gonna do lee's headers this Sunday. Saturday is probably available.

ratm68

iTrader: (8)

it's $100 for springs right? Sat's bad for me, is he able to do a weekday? like after hrs or something? Let me know, was going to wait for my g/f's brother in law, but he been busy so might just have him throw em on.


~Khoa

LEK

well.... Then he might be able to do it real early on Sunday before Lee's header install. And yes its $100 for springs only. He doesn't do weeknights... he did my cats on a weeknight but I doubt he'll do it. Let me pm you his # and you can talk to him.

wnt1bd

iTrader: (1)

I still don't understand why you would take it off your car when you only lose power in the final 800-1000rpm's? I tried to explain this a while ago.....you may have lost some power up top, but when you are driving under normal circumstances you are getting more power. When you are racing from a dead stop with MREV you will pull harder to the point at which you lose power, at that point shift !!! You will go faster-faster because you are in the meaty point of your rpm band. It is a little difficult to explain, but the power you lose up top will only hurt you if you are racing someone at 60mph in 4th gear and running from there. Most races and driving is done in the 3000-6000 rpm band. I guess the only other factor I have is I ran at Capital many times without MREV and ran a consitant 14.0-14.1 at 99-100mph. After MREV install I took it out and ran a 13.92 @ 102.?? mph. I ran 2 other times that day and ran a 14.0? @101.?? and a 14.0? @ 102.?? I also dynoed before I did MREV and that was posted. Now I have installed my HKS and my Crawford's and I picked my top end back up.....just ask Jesus....sorry bro I had to put that out there.

terryw

yeah tofu when you raced that M3, you should shift early instead of going to redline and you would have end up a lot faster. its not about how high an engine can rev, its about staying in the powerband

G-Tofu

iTrader: (1)

Thanks Devon,

I did try to shift around 6.2 rpm when i raced with my buddy 350z and I did not even come close ......so i decided to shift it at 7.0 rmp and we were both dead even up to 110 then i started to pull slowly.... so i tried the new set up....by getting headers + 1/2" spacer, cuz headers will give you good mid range hps and 1/2 spacer + REVUP lower collector will help me at top..... I will retune my car and see if there is any difference in hp/tq numbers........I always want to take advantage of 7.1rmp .....btw, most of my race was from the roll (40-60mph)....

wnt1bd

iTrader: (1)

Hmmmm......I want to race your buddies 350z.....I pull on most Z's right out the box...then run them to death all the way through.

G-Tofu

iTrader: (1)

^^^ this Z is very quick for some reason.......may be, i am still new with stick shift heh.... definately you may want to check him out....... we had it on video though ....

Jee_35

devon can drive.. :P

nmanti

What condition is your MREV+ in? I may be intersted in taking it off your hands.

yacoub

exactly!

To make the point easier, let's simplify the situation:

Say +5% over the first 90% of the rev range, versus -5% over the last 10% = gains during 90% of your acceleration. When combined with shifting a little earlier to avoid the 10% where you lose some, you should be gaining performance in general by a good amount.


The area in blue is much greater than the area in purple. Plus since the area in purple is just at the top of the range in this example, it can even be avoided/cut off by simply shifting at the point where the green line intersects the orange one.

On the actual graph (http://kahn.bol.ucla.edu/revupdyno.gif) we can see that the ideal thing in that setup is to shift around 6100rpm, although that does seem a bit low... not sure where that drops the revs to in the next gear (though that partially depends on how quickly one shifts or if you shift w/o letting up on the gas, etc). Either way, it IS intersting to note that the ONLY place it loses is at the top of the rev range - after 6k rpms. Everywhere else it's either the same or gaining performance, if those graphs are accurate.

Hydrazine

iTrader: (3)

The image you linked above is MREV2 without the plenum spacer.

MREV2 with 5/16" Iso Thermal spacer is what you really want.

The image below is using both together and compared to baseline. There is no contest between which curve is better than the other.
The MREV2/spacer combo are the two lines on top. The other three lower on the scale are stock baseline.



.
EDIT: BTW that was a cool illustration you made with the power curves.

Hydrazine

iTrader: (3)

It is also interesting to note that cars are not sold by area under the power curve. They are sold to the masses based on peak HP ratings.

I think what Nissan did with the REVUP plenum was optimize the marketing/advertising numbers rather than optimize area under the curve.

It makes good sense if only from a magazine advertising point of view.