3.9 liter (big bore), CNC head/cammed VQ build..
03-10-2010, 02:57 PM
#1
3.9 liter (big bore), CNC head/cammed VQ build..
My customer's (Barry) car will be going under the knife in the coming months.
After running 12.29 @ 110.82mph, 2 seasons ago, it's time for a freshen up..
The goal is to improve upon the numbers, and to provide a strong/reliable setup. While power will be bumped, substantially, we will also focus on balancing, and traction mods. I am also trying to pull some strings to get my hands on a new slick, in the size that we need, that's not yet on the market. Here's a few mods that we have planned..
Sleeved block
Custom CP pistons (Big bore @ 101mm)
CNC ported DE cylinder heads (330cfm/224cfm @ .525" lift)
1mm oversize valves
Custom cams by JWT (.520" lift)
Custom sheet metal intake manifold
90mm throttle body
4" cold air intake tube w/ ram air ducting
Custom long tube headers with 2.5" collectors
2.5" to 3" equal length y-pipe
3" exhaust
550cc injectors
TS custom flash, and SAFC for fine tuning
8200rpm rev limit
Custom air bag helper system in the rear, to adjust the amount of squat/weight transfer on launch.
Ballast plates, where needed, to aid in traction.
Lower engine as much as possible (thanks to J and Joe for the suggestion)
There's a few more surprises in store, but, I'll leave it at that, for now.. If my math is correct, then we should be able to crack 350-360whp on pump gas/meth injection. We'll see..
Travis
After running 12.29 @ 110.82mph, 2 seasons ago, it's time for a freshen up..
The goal is to improve upon the numbers, and to provide a strong/reliable setup. While power will be bumped, substantially, we will also focus on balancing, and traction mods. I am also trying to pull some strings to get my hands on a new slick, in the size that we need, that's not yet on the market. Here's a few mods that we have planned..
Sleeved block
Custom CP pistons (Big bore @ 101mm)
CNC ported DE cylinder heads (330cfm/224cfm @ .525" lift)
1mm oversize valves
Custom cams by JWT (.520" lift)
Custom sheet metal intake manifold
90mm throttle body
4" cold air intake tube w/ ram air ducting
Custom long tube headers with 2.5" collectors
2.5" to 3" equal length y-pipe
3" exhaust
550cc injectors
TS custom flash, and SAFC for fine tuning
8200rpm rev limit
Custom air bag helper system in the rear, to adjust the amount of squat/weight transfer on launch.
Ballast plates, where needed, to aid in traction.
Lower engine as much as possible (thanks to J and Joe for the suggestion)
There's a few more surprises in store, but, I'll leave it at that, for now.. If my math is correct, then we should be able to crack 350-360whp on pump gas/meth injection. We'll see..
Travis
03-10-2010, 08:34 PM
#7
The VQ40 has a 29mm taller deck than the VQ35DE.. not 10mm.
The bell housing bolt pattern is totally different on the Frontier block, as well. The mount holes in the block are in a different spot..
It actually has a decent rod/stroke ratio (1.80:1) because of the 166mm rod, but, it carries with it, a LOT more mass. If you're looking to build a 8K rpm monster.. a big bore VQ35 makes more sense. It might make those numbers, but, that's not the way that I'd go about it. I'll take a bigger bore over a stroker..
Travis
Last edited by TurboS13Hatch; 03-10-2010 at 11:05 PM.
03-10-2010, 11:11 PM
#9
The 90mm TB and 4" CAI will make more power.. Remember, 4 liters, aiming for over 400bhp N/A.
I have thought about rewiring the car for UTEC.. Wasn't there a guy that made a conversion harness that made it plug/play for the 5.5 gen guys? That's the harness that we're using.
Travis
03-10-2010, 11:12 PM
#10
03-10-2010, 11:38 PM
#11
Was actually thinking about a cloverleaf shaped chamber or other reshaping to promote a more complete burn than the stock heads can achieve. This would lower the octane requirement and give even more headroom when it comes to choosing a high C/R and running more aggressive a/f and timing maps (actually wouldn't need as much timing to make power as I'm sure you know). Widening the bore is counter-intuitive to these positive characteristics due to the fixed rate at which gasoline burns and the extra ground the flame front will have to cover. I have been wondering about this for a few years re: built n/a VQ's seeing that the Nismo VQ35DE competition heads (stage 1 and 2) use the VQ30's more compact combustion chamber as the basis for their design. And to my knowledge no one has modified VQ35 heads to such an extent on a street-based vehicle. Has your machinist addressed the merits of such an upgrade or if he thinks it would be worthwhile? Just throwing it out there...might get shot down.. 
Either way, look forward to seeing the transformation this engine will undergo!
Either way, look forward to seeing the transformation this engine will undergo!
03-11-2010, 01:05 AM
#15
The member's name is surraTT. Hes still testing the harness he has, something about problems with UTECs that are bought used not working 100% with the harness. He says it should be out in not too long, but it seems like hes been testing it forever
03-11-2010, 06:07 AM
#16
SurraTT (Darren I think) is a great guy. The problem with the UTEC is the cold. Below 50-60deg, expect misfires and stumbling.
NISMO has had great success with the VQ30 heads.
Travis, btw I was just busting your ***** about Kevin. I dunno what he's doing, but if history repeats itself expect ANOTHER epic thread to come up soon. I love seeing the envelope being pushed. Funny that its the sentra guys doing it.
NISMO has had great success with the VQ30 heads.
Travis, btw I was just busting your ***** about Kevin. I dunno what he's doing, but if history repeats itself expect ANOTHER epic thread to come up soon. I love seeing the envelope being pushed. Funny that its the sentra guys doing it.
03-11-2010, 09:10 AM
#17
03-11-2010, 10:04 AM
#19
That's a negative ghostrider. The Nismo heads have vq35de intake ports and identical port angle. The only thing they have in common with vq30 heads is the 46cc combustion chamber and valve sizes. IIRC they even use the long-reach 3.5 spark plugs. It's the best of both worlds; the superior flow of the 35DE heads (they flow even better than stock as you would expect) and the compact combustion chamber of the 3.0. Don't want this to get too far off topic so I'll digress.
I agree that this beast should be tuned by a UTEC at least. Selling the TS would cover most of the cost off the bat! I am also curious about the huge injector size.
I agree that this beast should be tuned by a UTEC at least. Selling the TS would cover most of the cost off the bat! I am also curious about the huge injector size.
03-11-2010, 10:17 AM
#20
That's a negative ghostrider. The Nismo heads have vq35de intake ports and identical port angle. The only thing they have in common with vq30 heads is the 46cc combustion chamber and valve sizes. IIRC they even use the long-reach 3.5 spark plugs. It's the best of both worlds; the superior flow of the 35DE heads (they flow even better than stock as you would expect) and the compact combustion chamber of the 3.0. Don't want this to get too far off topic so I'll digress.
Travis, I'm surprised you are not going after the full revup head swap.
03-11-2010, 11:35 AM
#21
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Join Date: Oct 2008
Posts: 177
That's a negative ghostrider. The Nismo heads have vq35de intake ports and identical port angle. The only thing they have in common with vq30 heads is the 46cc combustion chamber and valve sizes. IIRC they even use the long-reach 3.5 spark plugs. It's the best of both worlds; the superior flow of the 35DE heads (they flow even better than stock as you would expect) and the compact combustion chamber of the 3.0. Don't want this to get too far off topic so I'll digress.
I agree that this beast should be tuned by a UTEC at least. Selling the TS would cover most of the cost off the bat! I am also curious about the huge injector size.
I agree that this beast should be tuned by a UTEC at least. Selling the TS would cover most of the cost off the bat! I am also curious about the huge injector size.
.
03-11-2010, 11:37 AM
#22
It's cool.. I take it in stride.
I've pushed the envelope since day one.. I know that you haven't known me for very long, but, I've done some pretty cool stuff with the B15 chassis since 2001. I was rocking the B15 before the Spec V even came out. I had the first SR20DET swapped B15 SE, back in 2001, and was running 11's at the drag strip when people didn't even know what type of car it was. I'd get comments at the strip, like.. "That's one of those new WRX's!!".. Nope.. Just a Sentra. Travis
03-11-2010, 11:39 AM
#24
03-11-2010, 11:15 PM
#30
There is no set schedule as of now.. The block is sleeved, and the pistons are being finished (had to get valve reliefs cut in for the higher lift cam). Basically, Barry will dictate the schedule, as he plans on doing this build in steps. I'd say, mid summer or so, but, it's really up to him on the timeline.
Travis
Travis
03-12-2010, 06:01 AM
#32
03-12-2010, 01:05 PM
#34
Nah, let's face it.. no one can really afford to toss around that kind of money all at once, in this economy.. And, the fact that I have other work in front of me, all sort of works out for both of us. It gives Barry time to spread the cost out, and it gives me time to split the work up into chunks, while still allowing me to work on other stuff in the meantime. It's a win/win..I think that the increase in displacement, will broaden the curve overall, so, the bigger cams really won't be as noticeable a loss on the bottom end as it would be, if we were keeping the stock displacement. Good tradeoff, because the bigger cams will have a LOT to offer up top.
Travis
03-12-2010, 04:59 PM
#35
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I think that the increase in displacement, will broaden the curve overall, so, the bigger cams really won't be as noticeable a loss on the bottom end as it would be, if we were keeping the stock displacement. Good tradeoff, because the bigger cams will have a LOT to offer up top.
Travis
Travis
03-12-2010, 05:10 PM
#36
That exhaust setup has been something I have been talking about for over a year now, glad to see you guys are gonna do it. I really think this thing will be just pure awesome to drive.
GL
GL
05-29-2010, 11:49 AM
#38
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Location: Renton, WA
Posts: 44
05-31-2010, 12:02 AM
#39
I'll be running JWT's new C9 cams.. and I'm working with a company to have a CNC head porting program written to my specs. This is happening as we speak, and when we're finished, a STRONG 350+whp N/A VQ should be the end result.
Travis
Travis
