310 RWHP with stock intake
08-26-2008, 07:52 PM
#41
Registered User
Join Date: Sep 2005
Location: utah
Posts: 84
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Z1 Performance
I can't see why/how you are out of injector - what fuel pump are you running? I know the ~ CR that you get with those heads with std pistons, and that shouldnt put you out of range of the stock injector/pump.
If you're allowed to run full MAP, and get rid of the MAF, you might gain a bit of headroom on the injectors as well
If you're allowed to run full MAP, and get rid of the MAF, you might gain a bit of headroom on the injectors as well
He's probably using VQ30 stock injectors is what I'm thinking
08-26-2008, 10:44 PM
#43
Registered User
Join Date: Dec 2007
Location: Edmonton, Alberta, Canada
Posts: 165
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by LILjiMMYj0NES
VQ30 heads fit the VQ35 motor? WOW!!
Im gonna try to put a 2JZ head on each side of mine.Mad flow yo!
Im gonna try to put a 2JZ head on each side of mine.Mad flow yo!
not sure if you're sarcastic or serious about your question with the vq30 heads fitting the vq35de. . .
the nismo heads are the casts of the vq30 heads with the intake port design from the vq35de. . .
http://www.nismo.co.jp/en/products/c...ne/vq35de.html
08-27-2008, 01:19 PM
#44
Z + Rear Seat
iTrader: (3)
Join Date: Jun 2005
Location: St.Pete,FL
Posts: 1,642
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by mchris
I bougt JWT blanks and had WEB cam cut them. I do not remember the profile # but it was a 278 degree @ .050" with .470" lift.
With the Nismo titanium valves, thats all the lift you can run because of the step in the valve stem. I run the cams on 102 lobe centers. This was originally on my vq30 block. I just swapped it all over to vq35 block. With the comparibly gentle ramps of these cams compared to stock, the JWT valve spring is all you need to run to 8k rpm. Those stock cams slam the valve open and closed. I probably should have dialed some of the overlap out of it for the restricted motor. The drop in HP at 7.5k rpm is probably due to the 37mm SIR. Chris
With the Nismo titanium valves, thats all the lift you can run because of the step in the valve stem. I run the cams on 102 lobe centers. This was originally on my vq30 block. I just swapped it all over to vq35 block. With the comparibly gentle ramps of these cams compared to stock, the JWT valve spring is all you need to run to 8k rpm. Those stock cams slam the valve open and closed. I probably should have dialed some of the overlap out of it for the restricted motor. The drop in HP at 7.5k rpm is probably due to the 37mm SIR. Chris
I'm not familiar with the acronym SIR. What does SIR stand for?
Thanks a lot for all the information on your motor. It's obvious that you have a few tricks that none of us have heard before. The VQ30 heads is a slick concept.
08-29-2008, 07:51 AM
#45
Registered User
Thread Starter
iTrader: (4)
Join Date: Aug 2008
Location: mass
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
SIR stands for single inlet restrictor. The SCCA uses them to cap HP to equilize classes. And using the vq30 heads is because of easy compression and the larger 35mm lifter bucket. It allows for a larger base circle on the cam. You should look at the stock cams. The ramp is almost flat. So you go from no lift to max lift in very quickly. And then it slams closed almost as quickly. Look at the length of time a long duration cam has to lift the valve open. The valve spring at 7k rpm is working much less to control the valve. Add to that a titanium valve and a lightwieght lifter, and you can see why very little valve spring is needed. So all you guys with the heavy valve spring are just losing HP.
Chris
Chris
08-29-2008, 08:04 AM
#46
Former Sponsor
iTrader: (564)
Join Date: Feb 2003
Location: Long Island, New York
Posts: 19,266
Likes: 0
Received 5 Likes
on
5 Posts
Originally Posted by mchris
SIR stands for single inlet restrictor. The SCCA uses them to cap HP to equilize classes. And using the vq30 heads is because of easy compression and the larger 35mm lifter bucket. It allows for a larger base circle on the cam. You should look at the stock cams. The ramp is almost flat. So you go from no lift to max lift in very quickly. And then it slams closed almost as quickly. Look at the length of time a long duration cam has to lift the valve open. The valve spring at 7k rpm is working much less to control the valve. Add to that a titanium valve and a lightwieght lifter, and you can see why very little valve spring is needed. So all you guys with the heavy valve spring are just losing HP.
Chris
Chris
09-08-2008, 10:31 AM
#47
Registered User
Proof of stiffer valve springs causing significant HP losses please.
All a stiffer valve spring will do is cause more friction between the lobe and bucket in a bucket tappet system (still nothing compared to the frictional losses caused by the piston rings). There are no other losses involved. I'll take that extra bit of friction and over-rev protection over even the mere possibility of valve bounce, thanks.
All a stiffer valve spring will do is cause more friction between the lobe and bucket in a bucket tappet system (still nothing compared to the frictional losses caused by the piston rings). There are no other losses involved. I'll take that extra bit of friction and over-rev protection over even the mere possibility of valve bounce, thanks.
Last edited by nismology1; 09-08-2008 at 10:36 AM.
09-14-2008, 12:10 PM
#50
Registered User
iTrader: (2)
Join Date: Jan 2005
Location: Whorelando
Posts: 2,995
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Andrei
He might have HP but not torque so what does it matter. Torque is what wins a race.
Last edited by RBlover69; 09-14-2008 at 12:12 PM.
09-15-2008, 05:26 AM
#51
Former Sponsor
iTrader: (564)
Join Date: Feb 2003
Location: Long Island, New York
Posts: 19,266
Likes: 0
Received 5 Likes
on
5 Posts
There is no theory to be proven wrong - both hp and torque are important considerations when overall engine performance is concerned. Neither one on it's own is a guarantee of superior performance. Gearing, weight and rpm range play just as important of a role as horsepower and torque do, and in some circles, these things are even more important. Gauging performance without considering all these other factors is interweb racing at it's finest - and is meaningless
09-15-2008, 10:01 AM
#52
Registered User
iTrader: (2)
Join Date: Jan 2005
Location: Whorelando
Posts: 2,995
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Andrei
^I've seen plenty of FIed F bodies beat high HP Supras to prove that theory wrong. That's why I like a stroked VQ.
think about it with the laws of physics lol.
10-19-2008, 09:32 AM
#53
HP is all that matters, gearing can make up for lack of torque.
I would be interested to compare the Nismo Spec-2 ported VQ30 head to the cosworth heads. Cosworth has less CC and less compression, however larger valves.
Looking at the rough graphs on Nismo's site and Cosworth's site it looks like the cosworth heads flow more, but so hard to compare two different flow charts to one another.
I would be interested to compare the Nismo Spec-2 ported VQ30 head to the cosworth heads. Cosworth has less CC and less compression, however larger valves.
Looking at the rough graphs on Nismo's site and Cosworth's site it looks like the cosworth heads flow more, but so hard to compare two different flow charts to one another.
11-30-2008, 05:11 PM
#54
Registered User
iTrader: (1)
Join Date: Apr 2008
Location: Greensboro, NC
Posts: 84
Likes: 0
Received 0 Likes
on
0 Posts
http://vettenet.org/torquehp.html
and remember, HP is derived from torque, you can't have one without the other.
-------------Torque * RPM
Horsepower =------------
-----------------5252
---------Horsepower * 5252
Torque = -----------------
---------------- RPM
Last edited by Sparks03Max; 11-30-2008 at 05:25 PM.
Thread
Thread Starter
Forum
Replies
Last Post
350Z_Al
Exterior & Interior
133
10-29-2020 07:44 PM
