346whp @ 0 pounds of boost
I didn't use an HR Y pipe, it was HR headers. I got them for free. Here's a better explanation:
I don't know if they made more power or not. It's a long story regarding why I couldn't get the change dyno'd. They are basically shorty header with OEM engineering behind them.
I don't know if they made more power or not. It's a long story regarding why I couldn't get the change dyno'd. They are basically shorty header with OEM engineering behind them.
Who are you asking? My heads and valves are stock- just JWT valve springs to handle the more aggressive cam profile.
Thanks for saving me the hassle of trying to find a better intake setup then. I am running a pop charger and Kinetix V+. Must be the header/test pipe combo holding things up, but 2-3 thousand dollars is a big gamble. I'm so in the hole from building the engine, then there are track fees, memberships, and tires for 2011. As much as I would love to help test the SG long tubes, it will be at least a year before I can even think about it.
Thanks for saving me the hassle of trying to find a better intake setup then. I am running a pop charger and Kinetix V+. Must be the header/test pipe combo holding things up, but 2-3 thousand dollars is a big gamble. I'm so in the hole from building the engine, then there are track fees, memberships, and tires for 2011. As much as I would love to help test the SG long tubes, it will be at least a year before I can even think about it.
Registered User
iTrader: (3)
Joined: Dec 2008
Posts: 1,447
Likes: 0
From: Rapid City, SD Ellsworth AFB
Going to be following SG now. I'm planning my bolt ons as of now and trial and error is not my cup of tee. I want what works and it seems SG is definitely paving the way.
^UpRev actually have a pkg that allows you to integrate the GM TB into their tuning software. Contact them or I can forward you an email if you PM me.
TBH, I don't think that a 90mm TB will bring gains if the cams and exhaust can't get the air in and out any faster. That is a sort of situation that you bring to JWT or your camshaft manufacturer and ask for data on how big the intake pipe/TB can be (or needs to be) before the intake outflows (or is optimized by) the cams and headwork.
I think that's why SG has the C10 in the intake, because the GM TB flows WAYYY more than stock and the cams and manifold can take advantage of it. They basically blew out the intake opening and are now trying to find cams that will fill it.
TBH, I don't think that a 90mm TB will bring gains if the cams and exhaust can't get the air in and out any faster. That is a sort of situation that you bring to JWT or your camshaft manufacturer and ask for data on how big the intake pipe/TB can be (or needs to be) before the intake outflows (or is optimized by) the cams and headwork.
I think that's why SG has the C10 in the intake, because the GM TB flows WAYYY more than stock and the cams and manifold can take advantage of it. They basically blew out the intake opening and are now trying to find cams that will fill it.
Last edited by kacz07; Dec 17, 2010 at 06:11 AM.
Well, The Cosworth manifold has taken a lot of criticism from NA applications, but with SG's research w/ the lower revup plenum, it appears that neither the rev up or Cosworth manifold have the same torque curve as the standard bolt on Z. This may have been throwing some people off because their cars don't rev high enough to take advantage of the specific RPM range at which the Cosworth/Revup manifolds work. They just see a plateau in HP around the same RPMs that the MD/Crawford/APS manifolds continue and don't rev it past that to see how the torque holds steady. Both manifolds appear to lower the peak torque, but allow it to be made MUCH higher in the rev range.
All this being said, Cosworth's NA short block features oversized valves. Short answer, they are part of an optimized, free flowing, big cam, high revving motor AND will help out in that, and only that, specific NA application. If that is your end goal, then yes, oversized valves will help. If you scrap it and go FI, they will also help then. It depends on your goals.
Of course, someone please correct me if I'm wrong.
All this being said, Cosworth's NA short block features oversized valves. Short answer, they are part of an optimized, free flowing, big cam, high revving motor AND will help out in that, and only that, specific NA application. If that is your end goal, then yes, oversized valves will help. If you scrap it and go FI, they will also help then. It depends on your goals.
Of course, someone please correct me if I'm wrong.
My plan is high compression NA motor. I have a 5k budget for the motor more or less and am researching the best way to proceed. I am at 271/262 on my boltons/UPREV and am looking for 310/300 reliable results which I think is a reasonable goal.
^Well, you're pretty set w/ your final drive and current bolt ons.
Honestly, I'd switch the Rev up lower plenum back in, throw in some JWT valve springs and shims (which I don't believe are that tedious of an install), and see what a retune brings when you rev it out to 7500rpm. With the revup lower plenum, your HP should, in theory, plateau at 6k and then surge back up to 7k, so long as your exhaust is large enough. This powerband contrasts the standard NA/bolt on HP peak at 6250 w/ the non revup lower. See SG's dyno of Nonrev vs. Revup below for reference:
The cam you choose will determine if you reach 300whp. Z1 and others have mentioned that the car can break 300whp w/ the stock diameter intake/tb setup, so don't be discouraged by the intake.
If you want a high rev engine, get the JWT springs/shims, select a cam as big or larger than one involved in the SG cam shootout, and massage the exhaust (header specifications are key). Don't worry about the compression. If you don't need to rev higher than 7.5 or so, then you don't need to worry about building your bottom end.
So, I'd make your next steps:
JWT springs/shim kit
Revup lower plenum (keep your spacer)
Rev limiter to 7500 or 7750
Retune
THEN
Talk to JWT or another camshaft manufacturer when you're ready to install cams
Honestly, I'd switch the Rev up lower plenum back in, throw in some JWT valve springs and shims (which I don't believe are that tedious of an install), and see what a retune brings when you rev it out to 7500rpm. With the revup lower plenum, your HP should, in theory, plateau at 6k and then surge back up to 7k, so long as your exhaust is large enough. This powerband contrasts the standard NA/bolt on HP peak at 6250 w/ the non revup lower. See SG's dyno of Nonrev vs. Revup below for reference:
The cam you choose will determine if you reach 300whp. Z1 and others have mentioned that the car can break 300whp w/ the stock diameter intake/tb setup, so don't be discouraged by the intake.
If you want a high rev engine, get the JWT springs/shims, select a cam as big or larger than one involved in the SG cam shootout, and massage the exhaust (header specifications are key). Don't worry about the compression. If you don't need to rev higher than 7.5 or so, then you don't need to worry about building your bottom end.
So, I'd make your next steps:
JWT springs/shim kit
Revup lower plenum (keep your spacer)
Rev limiter to 7500 or 7750
Retune
THEN
Talk to JWT or another camshaft manufacturer when you're ready to install cams
Last edited by kacz07; Dec 17, 2010 at 07:06 AM.
You first need a plenum with a 90mm opening to make any sort of use of a 90mm throttle body, as well as a plenum designed around that throttle body (one that can support the volume increase without sacrificing velocity). Not to mention a place to put it (won't fit in the stock location). The software part of it would be comparitively easy. I'd venture to say that what makes Sasha's setup work well is that the intake manifold was designed around the throttle body. The plenum design may have changed if a different size throttle body was used.
Such a large throttle body without cams is likely of little use. Your engine is an airpump and in an NA setup, it is being forced to suck air in. Sucking more may sound better, but again, the rest of the setup has to be able to accomodate it. Larger valves without cams is definitely of no use - even with cams they are not a guarantee of anything, though some of the aftermarket valves, even larger, might be lighter than stock valves (this would give the benefit of lower reciprocating mass and give a livlier, more response engine). Some aftermarket valves, even stock size, can gain some cfm because of the way the face is designed vs stock. For guys doing big boost, they tend to have a nice gain because air is being forced in, and LOTS more of it than an NA setup could ever generate. Cosworth's engine had larger valves for one main reason - their heads come that way and it was a showcase build of their products. Cosworth also used a stock throttle body. Yes, certainly all worked well together, no doubt about it. But by comparison, NISMO's heads for DE's feature smaller valves. And RSC doesn't have larger valves (although they use ITB's, in an airbox, which changes the game and requirements). Taikyu cars didn't feature larger valves. Not sure what the Euro guys run either on the Nissan or Renault side, sometimes really hard to get the finite details on those engines. But again, it's not about 1 part, or 2 parts - it all has to work as a unit. Throwing parts at it gives you a bigger bill and more stuff to pack into your signature but doesn't ensure power. I didn't do larger ones on my car, and instead focused on getting the stock ones to seat and seal properly, which is what is 'lacking' in stock heads (though they are amazing heads for stock pieces...most other car owners would kill to have heads as nice, let alone as nice from the factory).
Kaz is spot on with the Cosworth manifold and the revup manifold. The revup trades low and midrange torque and hp for higher rpm power, due to the change in runner length, but it too falls off in the 7500 range (cam dependant). A properly ported non revup lower does the same (this is what I previously had on my car). A Cosworth will keep things pulling nicely in the upper rpm range (I redline at the same 8400 as I always did, but now the hp curve peaks in the low 7000's and stays flat to redline, no taper downward like before. It does trade, again, lower end grunt for top end pull, due to it's internal volume and runner design. But it does so while retaining a stock throttle body, which is important. That's why I am glad I have even shorter gears now to 'regain' the down end grunt I lost. It doesn't have the bottom end pull that it used to, but it pulls up top better than ever. Everything is a trade off, and having lived with it for 8 months now or so, I wouldn't go back. I don't mind an engine that you need to wind out.
A 70mm throttle body is quite large for 3.5 liters of displacement and 24 valves. The only reason I went to the larger unit I use now (76mm IIRC, gotta check my own thread), is that I had converted the car from drive by wire to cable for the failed ITB project I embarked on. When that didn't pan out, I was left without any of my previous stuff, as I stupidly sold it off thinking I no longer needed it. So, I chose to go with the Cosworth plenum, who's mouth was just big enough to accomodate the throttle body I went with. Had to modify the bolt holes slightly, but I found a throttle body that was nearly spot on and fit in the stock location.
As for what to pick cam wise, again, you gotta be careful when you say "pick a big cam". As the test shows, the advertised numbers mean squat. You need the full picture, to know what will work well with what. The cam tests Sasha has been doing are good because it helps shed light on this, and it shows that it's more than just a "264 vs a 272" and so on. You can have a 264 duration cam that is WILD compared to a 272 or even 280. Cams are simple, yet complex devicesa the same time. That's why 50 years on, you've still got companies developing cams for big blocks, small blocks, etc. There are constant developments that are made both in the design and manufacture of the cam itself, as well as in the stuff the cam relies on to operate fully. It's just an ever evolving science.
As for not needing to build the bottom end, I would say that is at best debatable, particularly on a non revup. It just hasn't been done with any regularity (at least here) to know how safe (I'm talking long term safe, not 6 months safe) it really is. The bottom end of that motor, even a revup, just was never conceived, nor balanced anywhere remotely close enough to sustain those revs long term. Neither are the oil passages, or bearing clearances designed with those sustained revs in mind. Just take a look at the pics in the first page of my build to see what was done to the crank on my motor to give you sort of an idea on what you're looking at. If I had an HR, I wouldn't have built it, as we've torn those things apart and seen that they would sustain what I'd personally want to put it through. For the others, I'd still opt to build it, but YMMV. I'd just rather not take the chance. The goal on mine from the outset was something that would rev, sustain those revs if needed, and last, long term. So far, it's been 3.5 years. It was never max, ragged edge power, as it still needed to be civil, idle well, cruise well, get decent enough mileage for long highway cruises that I do, etc. I didn't want to be forced to build another bottom end in the future unless I chose to. As things/time went on, I chose to see what we could get out of it, but it's always with the caveat that it has to remain civil, and reliable. I'll trade 10-20 whp for that peace of mind, as I already did way more to this thing than I ever planned on. But at the same time, when you mod to this level and have so much time and resources involved, complacency is hard to achieve, so I am sure I'll be looking to the next step at some point.
Such a large throttle body without cams is likely of little use. Your engine is an airpump and in an NA setup, it is being forced to suck air in. Sucking more may sound better, but again, the rest of the setup has to be able to accomodate it. Larger valves without cams is definitely of no use - even with cams they are not a guarantee of anything, though some of the aftermarket valves, even larger, might be lighter than stock valves (this would give the benefit of lower reciprocating mass and give a livlier, more response engine). Some aftermarket valves, even stock size, can gain some cfm because of the way the face is designed vs stock. For guys doing big boost, they tend to have a nice gain because air is being forced in, and LOTS more of it than an NA setup could ever generate. Cosworth's engine had larger valves for one main reason - their heads come that way and it was a showcase build of their products. Cosworth also used a stock throttle body. Yes, certainly all worked well together, no doubt about it. But by comparison, NISMO's heads for DE's feature smaller valves. And RSC doesn't have larger valves (although they use ITB's, in an airbox, which changes the game and requirements). Taikyu cars didn't feature larger valves. Not sure what the Euro guys run either on the Nissan or Renault side, sometimes really hard to get the finite details on those engines. But again, it's not about 1 part, or 2 parts - it all has to work as a unit. Throwing parts at it gives you a bigger bill and more stuff to pack into your signature but doesn't ensure power. I didn't do larger ones on my car, and instead focused on getting the stock ones to seat and seal properly, which is what is 'lacking' in stock heads (though they are amazing heads for stock pieces...most other car owners would kill to have heads as nice, let alone as nice from the factory).
Kaz is spot on with the Cosworth manifold and the revup manifold. The revup trades low and midrange torque and hp for higher rpm power, due to the change in runner length, but it too falls off in the 7500 range (cam dependant). A properly ported non revup lower does the same (this is what I previously had on my car). A Cosworth will keep things pulling nicely in the upper rpm range (I redline at the same 8400 as I always did, but now the hp curve peaks in the low 7000's and stays flat to redline, no taper downward like before. It does trade, again, lower end grunt for top end pull, due to it's internal volume and runner design. But it does so while retaining a stock throttle body, which is important. That's why I am glad I have even shorter gears now to 'regain' the down end grunt I lost. It doesn't have the bottom end pull that it used to, but it pulls up top better than ever. Everything is a trade off, and having lived with it for 8 months now or so, I wouldn't go back. I don't mind an engine that you need to wind out.
A 70mm throttle body is quite large for 3.5 liters of displacement and 24 valves. The only reason I went to the larger unit I use now (76mm IIRC, gotta check my own thread), is that I had converted the car from drive by wire to cable for the failed ITB project I embarked on. When that didn't pan out, I was left without any of my previous stuff, as I stupidly sold it off thinking I no longer needed it. So, I chose to go with the Cosworth plenum, who's mouth was just big enough to accomodate the throttle body I went with. Had to modify the bolt holes slightly, but I found a throttle body that was nearly spot on and fit in the stock location.
As for what to pick cam wise, again, you gotta be careful when you say "pick a big cam". As the test shows, the advertised numbers mean squat. You need the full picture, to know what will work well with what. The cam tests Sasha has been doing are good because it helps shed light on this, and it shows that it's more than just a "264 vs a 272" and so on. You can have a 264 duration cam that is WILD compared to a 272 or even 280. Cams are simple, yet complex devicesa the same time. That's why 50 years on, you've still got companies developing cams for big blocks, small blocks, etc. There are constant developments that are made both in the design and manufacture of the cam itself, as well as in the stuff the cam relies on to operate fully. It's just an ever evolving science.
As for not needing to build the bottom end, I would say that is at best debatable, particularly on a non revup. It just hasn't been done with any regularity (at least here) to know how safe (I'm talking long term safe, not 6 months safe) it really is. The bottom end of that motor, even a revup, just was never conceived, nor balanced anywhere remotely close enough to sustain those revs long term. Neither are the oil passages, or bearing clearances designed with those sustained revs in mind. Just take a look at the pics in the first page of my build to see what was done to the crank on my motor to give you sort of an idea on what you're looking at. If I had an HR, I wouldn't have built it, as we've torn those things apart and seen that they would sustain what I'd personally want to put it through. For the others, I'd still opt to build it, but YMMV. I'd just rather not take the chance. The goal on mine from the outset was something that would rev, sustain those revs if needed, and last, long term. So far, it's been 3.5 years. It was never max, ragged edge power, as it still needed to be civil, idle well, cruise well, get decent enough mileage for long highway cruises that I do, etc. I didn't want to be forced to build another bottom end in the future unless I chose to. As things/time went on, I chose to see what we could get out of it, but it's always with the caveat that it has to remain civil, and reliable. I'll trade 10-20 whp for that peace of mind, as I already did way more to this thing than I ever planned on. But at the same time, when you mod to this level and have so much time and resources involved, complacency is hard to achieve, so I am sure I'll be looking to the next step at some point.