Project VF Part II - Let the CAMs Begin
Project VF continues with the installation of our Stage One camshaft...the ever popular SQ53. This is a great daily driver grind that is the product of many years R&D on LS family engines. We have an extensive overview of it on our VF Cam Upgrade Page. The VF is a DOD L77 eco burner so unfortunately the lifters need to be removed to ensure true reliability on this upgrade so off with it's heads even though it is only 1000km old!
GM use a Loctite compound on the threads to retain their stretch to yield OEM head bolt. This needs to be cleaned from all the head bolt holes so we chase the threads with a special order tap we have had made for the job.
Next the DOD lifters are removed (should be written as DUD!).
Harmonic balancer and timing cover removed allowing access to the cam gear and retaining plate.
Time for the replacement camshaft ground to our specs by Comp Cams in the good ol' USA! Lubed with Lucas Oil Products, in it goes.
Cam installed, we fitted and timed the three bolt LS7 cam gear with ARP bolts replacing the single bolt OEM core.
With the cam timed, timing cover is re fitted. When installing the harmonic balancer, we have again made a specific LS tool. This allows the balancer to be pulled back onto the crank rather than beating it with a hammer as seen by many other installers. It also maintains the integrity of the crank snout thread as we have seen many stripped by those who use the crank bolt to pull the balancer back on.
LS7 lifters are used to replace the DUD OEM units. This requires the use of Gen VI lifter trays. We don't subscribe to the use of tie bar lifters. Over 25 years of engine building we have experienced that the lifter when not tracking on the cam correctly will pull itself from the guide bar. To help the lifter track, the lifter must be crowned (the wheel not flat). The play in the tie bar allows the lifter to switch from one side of the roller to the other increasing the side thrust load on the wheel shortening the bearing life. OEM lifter trays align the follower in sets to the centreline of the cam. We have never seen one fail even when the lifter has broken below it. Guys spend $1000s to fit keyed lifters in race engines and GM pretty much included it in the price of the car. The tray stays!
An advantage of pulling the heads is it facilitates changing the valve springs on a bench. This allows for more accurate installation and easier access for spring height checks. On with the PACs. Ho! Ho! Ho!.
Springs fitted next step is to refit the heads with ARP head bolts. One of the many positives to come from having to pull the heads for the lifter change is that now we have the heads retained by a World class fastener and not a stretch to yield OEM piece. This provides us with more accurate clamp of the head gasket. Makes something better out of the extra costs in the cam change.
The ARP head bolts torqued to spec and springs lubed with Lucas Stabiliser to ensure proper break in (yes guys you do break in valve springs and it is best to do it with some lube cooling them) the rocker gear can be refitted. You will note here how we have taken the time to ensure that each pushrod goes back into the engine with the rocker that is ran on and onto the valve it came from for each cylinder. All these parts wear to each other. We want to ensure that each rocker matched the parts it has worn to. To mix and replace only makes the part wear in a new position often leading to accellerated deterioration of the part. You will also note that we are re using the OEM pushrod. We have found at the spring loads of the lightweight beehive spring that there is no gain at replacing the pushrod to a heavier walled piece...again our testing saves you $$ by allowing the best performance without having to buy parts you don't need.
Rocker gear installed it is time to close it up...
OTR back on and has this thing been apart? Oh yeah....theres no coolant in the radiator!
Landfill...OEM leftovers. A dish best never eaten...
Wideband intalled for testing air fuel ratios, fluids changed and topped off, engine ran up and at operating temperature the tuning begins. After some road logging at part throttle to cycle the new valve springs and adjust the drive fuelling it was onto the dyno. Predictably the SQ53 produced an impressive 60rwhp gain after careful calibration of the ECU. Looking closely at the graph the peak gain is only part of the story. The DUD camshaft stopped moving air at 5500rpm where as the SQ53 keeps moving it until peak power at 6200rpm where it shows a gain of near 80rwhp! The most impressive thing about the way that SQ53 does its thing is that it gains from 3200rpm all the way to peak over the OEM cam. At no point is there a loss of power from the original where as less well thought out cams will hollow out the low end engine speed power. This is what makes it a great camshaft for daily use. As seen in the photos, we have not had to install a higher speed stall converter as this cam idles in/out of gear at 750rpm, air con on, air con off without trying to creep the brakes. A high stall also isn't needed to mask the loss of low end torque that altering valve events often necessitates.
The graph below shows the gains of Projevt VF so far. We have included torque at the wheel in the graph here also. It is reluctantly that we do this because it is fashionable lately to start using calculations to show engine torque. Again in our view it isn't using the dyno for its true purpose. With the many variables that can effect peak power readings on a rolling road chassis dyno, we believe that only before and after power numbers are pure and relative to the modifications made. The same can be said for taking those readings as the tyre and putting them back through math functions to CALCULATE what was made at the flywheel. It was never measured so is only ever a guess based on calculation. Before and after is a definitive result. All chassis dynos are accurate when used in a controlled manner in that they will repeat the same readings over and over again...errors and all. None can be claimed to be precise regardless of brand and software. It is often asked what torque it will gain. You can't gain torque and not HP. All dynos use the following equasion to calculate the hp you see on the screen... torque x rpm/5252. If you want to play with a calculator for a bit using the formula, you will see that at peak torque as indicated on the graph of 393.2ft/lb as measured at the roller @ 5000rpm it made 374rwhp at peak torque. Any increase in indicated power at any given rpm must come FROM an increase in measured torque.
So far the L77 has gained 100rwhp from its comparative peak horsepowers numbers. That is a 32% increase from how it was delivered to us from Holden.
The graph below shows us what happens when you up the ramp rate on the dyno. These readings are taken in ShootOut 8F. This stands for 8Fast. There is no change to the VF to make these numbers just a different sample rate in the dyno calculations. We take these readings now as some are using them to rate peak power. Shootout 8F was only ever included in Dyno Dynamics software for high powered auto cars and blown vehicles. That some are now using it to sell horsepower on simple cam only and bolt on cars is outside its intended use. As can be seen below Project VF gained another 24 rwhp. If you are asking how much power it will make when researching a cam package and the operator gives you the numbers from 8F it is more impressive and will likely result in the belief that it is making more power...like wise when the baseline is in ShootOut8 as in this graph. If we were to use the 8F peak against the base of 362rwhp that we had with exhaust and tune with cold air it would look like the cam gained 83rwhp! Make sure that apples are compared with apples.
Enough of the dyno games. Next we take it to the strip. Fingers crossed the tyres let us get some decent results there! Prediction? High 11 @116mph....if the tyres hang on.
115.53mph Anyone?
14/2/2014
Well the time cards are in. The air was tragic for making power at a corrected density altitude of near 2900' but Project VF with the SQ53 on board ripped of a 12.47@114.94mph straight off the road.
Later at the top 10 reaction time shoot out Project VF improved to 12.41@115.53mph. Not quite our predicted 116mph from the power gain we saw on the dyno but man how close is that? Air was still not outstanding for best power but this is a real world development project that we hope many to emulate...not the best of the best but everyday.
So the mph shows us we gained some nice power with the cam upgrade...a total of 11 mph in fact from standard but where is the ET? Time to scrutinise some numbers. The beauty of drag racing is that it is easily analysed in numbers taking away the mistique and the BS. "My mate has 800rwhp and runs 9.8 at the drags at 140mph with a 3800lb car...." We know that as long as the weight is held the same and the distance is ALWAYS the same to cover the distance in less time we applied more power over a greater period of time. But back to the VF...
Let's break it down...
Standard Stage One Improvement SQ53 Improvement Overall Gain From Standard.
60' Time 2.109 2.061 .048 2.038 .023 .071
330' Time 5.870 5.530 .34 5.434 .096 .436
Time Taken 60'-330' 3.761 3.469 .292 3.396 .073 .365
660' Time 8.921 8.366 .555 8.147 .219 .774
Time Taken 330'-660' 3.051 2.836 .215 2.713 .123 .338
1320' Time 13.65 12.77 .88 12.419 .351 1.23
Time Taken 660'-1320' 4.729 4.404 .325 4.272 .132 .457
Above we have a lot of numbers!! What I have shown is the time taken to get to each point on the track being the distance markers. I have then shown the improvement in time to get to each of those points referenced to the level of modification. I have also shown the time it takes to travel from each marker to the next and shown the gain. It becomes very clear that the extra power is giving a great gains after half track but we are really struggling getting an improvement to 60' and 330' (highlighted). Looking back at the dyno graph we can see we gained power in the lower rev range which is shown with the small gain to 60'. Careful analysis of the logs show that 330' is the top of second gear. The factory tight converter stuggles to flash any higher that 1800rpm on the step to WOT so the engine must pull itself from 1800rpm to the shift into second at 6400rpm. Once it is through first gear it never drops below 5400rpm again, keeping it in the steam. Obviously we could step all over the VF with a higher stall converter but we feel this distracts from the everyday drive of the car and the purpose of the SQ53. So we have decided to change the rear end ratio from the 2.92 that it left the factory with to a 3.27:1. Why not lower? 3.91 or the likes? From the ratios listed in the table below, the first gear ratio of the 6L80E is 4.027. Second is 2.364.
| 1 | 2 | 3 | 4 | 5 | 6 | R |
|---|---|---|---|---|---|---|
| 4.027 | 2.364 | 1.532 | 1.152 | 0.852 | 0.667 | 3.06 |
This pretty much gives the VF the same start line ratio as a 4L60E with a 4.30 rear! Any lower and we would start to see the VF want to change into overdrive once we pick up more speed later down the track when we step on it some more. We don't need to start dividing the power now do we?! Note that 4th isn't 1:1 in the 6L80E. 3.27 should give us the compromise we are after without gaining too many 6th gear rpms at cruise on the highway resulting in a negative impact on fuel economy. In fact it will only gain 200rpm...
So rear ratio is in with a Tru Trac limited slip to replace the bogus ZF offering. We will fit a converter after we test the ratio change but it will be a 3200 unit we have developed with Dominator that is relatively tight and still gives great seat of the pants drive as it is required with the SQ54 cam we will test next.
Call back soon to see what results we gain...
Ratio Results
20/3/14
The planets aligned and we got Project VF back to the track to see where the ratio change got us. Pleasingly we dropped 2.5 tenths over the quarter realising a best of 12.15@115.97mph. As can be seen on the time card, we dropped 1/2 tenth to 60', a full 2/10ths to 330' and 2.5/10ths to half track (660'). So the gears really bought it around.
Second run was the best of the night....
But all were right in the slot again showing the consistency of the tune and car.
Repeatable, reliable results...not best ofs or put ups.
Unfortunately it has become very clear with the struggle we now have with wheel spin that we need to get a tyre under the car. This is something we didn't want to do as we wanted to keep it as much real world daily driver as possible but we are just ripping off the potential of the VF if we don't. The OEM hoops just aren't in the game any more with traction being lost through 2nd gear and clear into 3rd. The screen shot below from the EFILive logs we are taking of the VF clearly show the level of spin....this can be seen via the vehicle speed sensor - v - engine rpm on the shifts...
1st-2nd...note VSS speed rapid increase...basically it goes to 6000rpm and stays there whilst the tyres try to find drive!
then the shift into 3rd...straight back up on the tyre!
So as much as we didn't want to do it, we are leaving too much time on the table to ignore using the OEM SSV Bridgies. We aren't going to slick it out either at this stage so on with some drag radials over 17" rims. Check back soon to see the improvement...can anyone say 11s on a standard converter?!
Tyres on.
10/4/14
After looking around for a short period we settled on some 17" Hoosier Drag Radials for Project VF. These were used as we could fit them over the OEM fitted rear brake using a rim from a VX SS. Tyres on and to the track to eliminate the pesky tyre slip...
Well what can you say? Not the desired result but what happened? How can we get rid of the tyre slip and go slower?! Quite simply the car with a tight converter NEEDED the slip to get it away. Once we hooked the tyre it pulled the engine down and made it lug losing time where as with it spinning the tyres the engine was free and able to hang in it's power band. Oh well. The best laid plans of mice and men hey? What next? Considering that Project VF is about to get hit with some bigger cams we reckoned it is time for a converter change...
Time To Dominate!
26/4/14
Busy shop and Shane's work schedule made it hard to get back to the track but finally we got the converter in the car. We went with our tried and true Dominator converter that will give a flash speed of 3400rpm with the SQ53 cam. It is a little looser than what we would normally use behind this cam but in the interest of not having to pull the trans again we went this way. We have worked with Dominator since the mid 1990s on converter applications and always get a great result from their product. They build to our requirements and offer the best product in this country by a long way in our opinion. It won't be the first time we have pulled a loose converter from another builder out, replaced with a Dominator and gained et and mph. So how did it go? Shane took it down to the Ford -v- Holden Day at the 'Plex on ANZAC Day and ran the wheels off it. Results below...
Smashing out those 11 second time cards!
No they aren't the same time card... just consistent...unlike the driver who struggled to get his reaction times where he needed to be to go some rounds of racing and got sent home second round! Clearly the converter got Project VF's attention. With a gain of 2.6 tenths (.26 seconds) it is an impressive pick up that puts the VF firmly into the 11 second zone. The massively pleasing thing is that we GAINED mph also. This proves the efficency of the converter and shows that with a well thought out design again you can have your cake and eat it! So with some carefully planned mods we have a consistant 11 second street car that is happy to run around the streets with full manners. But then we got to thinking...how good would this thing run in some fat air?
Fat Air
1/5/14
As we expected, the colder dense air produced a nice gain for Project VF dropping to a 11.79@116.27mph. Now this isn't everyday but shows where it can go in the right conditions.
The Air Density went subterranean (below sea level) and mph came up some more even though the cold track wouldn't hold the increase in power...
So that finalises the SQ53...daily driver with 11 second attitude. What we hope it proves is you don't need something that idles like a rotary, cruises like a busted shopping trolley and leaks fuel economy like the Exxon Valdez to achieve, what is our book, a very fast car in the 11 second bracket....at the flick of the ankle it lights the tyres through first and second gear and is plenty quick enough to make itself popular at the impoundment lot if used carelessly. We have used nothing outside the scope of readily available parts. Just chosen carefully to work together in a functioning combination. Next we will install our stage two SQ54 camshaft. Stay tuned.
<< Project VF Part I - The Baseline
Project VF Part III - Let the CAM's Continue >>