My cars development
Discussion
Just an update with my car for those interested. It's an LS7/6 speed vehicle.
My factory fuel system (change over switch) was clogged with fuel tank baffling, so engine has to come out for that job. Plus I really didn't like the design, so I put in a new system. In the mean time, also did some upgrades
- MSD intake manifold
- Custom ground big cam
- Redid whole fuel system (balance pipe (run as 1 tank), twin lift pumps, twin filters, two 044's in larger 3L surge tank, larger fuel rails)
- New valve springs, head studs, etc
- Heaps more heat shielding on the car, fuel tanks, etc (was boiling my fuel is lower than 3/4 tank....)
- New tune
Should see 700+hp easy, so GTR720 territory. Next upgrades will be suspension / driveline.
Photos below
My factory fuel system (change over switch) was clogged with fuel tank baffling, so engine has to come out for that job. Plus I really didn't like the design, so I put in a new system. In the mean time, also did some upgrades
- MSD intake manifold
- Custom ground big cam
- Redid whole fuel system (balance pipe (run as 1 tank), twin lift pumps, twin filters, two 044's in larger 3L surge tank, larger fuel rails)
- New valve springs, head studs, etc
- Heaps more heat shielding on the car, fuel tanks, etc (was boiling my fuel is lower than 3/4 tank....)
- New tune
Should see 700+hp easy, so GTR720 territory. Next upgrades will be suspension / driveline.
Photos below
My switch over valve thing was clogged, so bad it stopped working for a while and I only have the right tank. It's a PITA to change cause its right up in front of the engine on the firewall. The factory sent me a new valve, but glad I didn't swap it over cause if I had to change the hoses over in the crazy box it would have been ridiculous. So I just decided to redo the whole system because anyway the surge tank from the factory was only 1L, and the O44 was very loud mounted to the firewall (plus, I needed a second one anyway). Anyway, everything is a lot more serviceable now too (ie filter locations, etc)
Havn't run the car yet. Waiting on my second lift pump and some fittings to arrive. Car will be running Tuesday, then tuned later in the week. Should be "finished" (for now) by next weekend.
Standard heads, valves, push rods and rocker arms (the beauty of an LS7), but just upgraded valve springs and head studs. It's quite an aggressive cam, basically a cam from a GT3 Z06 with a bit less lift and lobe separation. Pretty much, slightly less agressive than this car: https://www.facebook.com/lsowners/videos/vb.139898...
The person tuning my car is a very well renowned LS tuner here in Australia (he basically just flys around the country tuning LS motors) and he suggested the parts list and said it will make 700hp pretty easily with the manifold. I'll let you know next week what it makes, how it drives, etc. Standard motor made 345rwkw for reference.
Havn't run the car yet. Waiting on my second lift pump and some fittings to arrive. Car will be running Tuesday, then tuned later in the week. Should be "finished" (for now) by next weekend.
Standard heads, valves, push rods and rocker arms (the beauty of an LS7), but just upgraded valve springs and head studs. It's quite an aggressive cam, basically a cam from a GT3 Z06 with a bit less lift and lobe separation. Pretty much, slightly less agressive than this car: https://www.facebook.com/lsowners/videos/vb.139898...
The person tuning my car is a very well renowned LS tuner here in Australia (he basically just flys around the country tuning LS motors) and he suggested the parts list and said it will make 700hp pretty easily with the manifold. I'll let you know next week what it makes, how it drives, etc. Standard motor made 345rwkw for reference.
Yes, I never understood the two tank thing either. Unnecessary complexity. I pick up and return into each tank, with just one of the -6 lines to balance it. I don't expect much movement between tanks, it's more just for equalizing it.
My surge tank can work with either a single pump, or two. So if you buy it, you've always got that capacity for future to add another pump. https://www.aeroflowperformance.com/tanks/fuel-sur...
My surge tank can work with either a single pump, or two. So if you buy it, you've always got that capacity for future to add another pump. https://www.aeroflowperformance.com/tanks/fuel-sur...
Abbosevolution - Further about the fuel system (as I'm probably asleep when you're awake, so writing it now). Basically it goes tank, filter, lift pump, surge tank, 044, rail, surge tank, return (one into each tank). I guess it's a pretty standard two tank system with a pipe at the bottom.
My theory with -6 being big enough or not is that that each tank is emptying at the same rate (the lift pumps flow rate) and less fuel than what was sucked up is going to return (as it's being burnt), the bigger that difference is the more WOT it is. And so considering the idea of path of least resistance, both tanks will return to the top of the tank, which is air, so resistance is minimal anyway.
So even if the pumps are +/- in flow rate, and the return is +/- in flow rate (tank to tank), I am not asking the balance pipe to flow any more than the real difference between the two return rates. I know that a -12 is 4x the surface area of a -6, but I don't see as much as a difference of 25% in return rates?
Has anyone tried to use a -6 before with issues?
I'll find out Tuesday when the car is started for the first time, it will be most obvious on idle with completely full tanks.
My theory with -6 being big enough or not is that that each tank is emptying at the same rate (the lift pumps flow rate) and less fuel than what was sucked up is going to return (as it's being burnt), the bigger that difference is the more WOT it is. And so considering the idea of path of least resistance, both tanks will return to the top of the tank, which is air, so resistance is minimal anyway.
So even if the pumps are +/- in flow rate, and the return is +/- in flow rate (tank to tank), I am not asking the balance pipe to flow any more than the real difference between the two return rates. I know that a -12 is 4x the surface area of a -6, but I don't see as much as a difference of 25% in return rates?
Has anyone tried to use a -6 before with issues?
I'll find out Tuesday when the car is started for the first time, it will be most obvious on idle with completely full tanks.
Abbosevolution said:
Alex - I had the same view regarding the returns but my swirlpot being on the drivers side means that one return is significantly longer than the other. The tank closest to the swirlpot filled significantly quicker because the weight of the fuel in the pipe and the force required to push it is less than the weight of the fuel in the longer return, hence the difference. The solution is to either make both returns the same length or improve the link pipe between the two tanks to make balencing quicker as Paul has done.
Unfortunately for me, I only have a -6 fitting on my tank, so I'll start with that as a balance pipe and go from there. I think there is no point trying to put a step up fitting/bigger hose etc, as the fitting itself is the restriction. The overflow on my surge tank goes into a Y piece, and upon your advice, I am going to run equal length (and similar bends) hoses to try my best to keep the rates of return as close as possible.
I used the old surge tank, 1L, and filled it with water and measured the rate of flow from the bottom fitting a) with no hose on the end, and b) with a hose on the end. a) emptied the 1L in 16 seconds, b) emptied the tank in 8 seconds. I presume the hose provides more laminar flow and hence drained faster.
So the approximate conclusion I draw is that a -6 balance pipe should be able to equalise side to side around 1L every 10 seconds if there is a 1L volume difference between tanks. I am happy to be corrected if someone sees fault in my theory?
My lift pumps are 420L/h, so 1.15L / 10 seconds, so even if there is a 50% different in return rate to each tank (I think that's unlikely), that's only half a litre per 10 seconds. So I conclude a -6 should be fine?
Just going to be annoying filling the car up at the servo I think as it will be balancing too slow to just fill one side.
UltimaCH said:
Alex, where are you fitting your twin pump surge tank? On the bulkhead downside somewhere?
The surge is mounted horizontally above the drivers side fuel tank with the pick ups on the pumps pointing towards the back of the car. 845ste said:
your cam which duration at .050 ex / asp? i have installed comp cam 231/237 (spring ecc)
I think it would be better to post a wiring diagram? with many solution?
My cam = 237 / 252 @ .050, .612 / .618 lift, 112 lobe sepI think it would be better to post a wiring diagram? with many solution?
chuntington101 said:
I think the MSD will be MUCH better in the mid range than the above! There have been loads of tests carried out and unless you are revving over 7k these short runner setups really don't add anything other than weight!
Yep - exactly my reason for choosing that manifold. It's cheap, around $1200 AUD, and also has runner lengths long enough that you don't lose bottom end / mid range, which is important to me on a road car. xrtim said:
does the single lift pump suffer from running dry when the fuel gets say 1/4 full under hard cornering with the fuel moving away from either fuel tank pick up (simple solution may be fill tank when 1/4 full)
would I be better off running two smaller lift pumps like the standard carters set up beside each fuel tank feeding into the swirl pot so either one will still be feeding the swirl pot under the same conditions or does this not happen at all and I'm worrying about nothing.
Looking good Tim!would I be better off running two smaller lift pumps like the standard carters set up beside each fuel tank feeding into the swirl pot so either one will still be feeding the swirl pot under the same conditions or does this not happen at all and I'm worrying about nothing.
Personally, I've opted for (2) lift pumps that out-flow my (2) high pressure pumps. This way, my surge tank will always be 100% full all the time.
Also, all my pumps are wired separately, so should one lift or high pressure pump fail, the system will continue to function albeit at a reduced power capacity.
Edited by AlexCim on Sunday 6th March 21:09
macgtech said:
The build in the picture above looks great!
Speaking from experience here, I think the balance pipe needs to be bigger than a -6, and importantly, the two tanks need to be linked at the top to allow air to travel between the two tanks too, ensuring that the lowest point of that 'breather' is the point at which is meets both tanks. We had issues with this at first but overcame them with a bigger link pipe.
I have no more nipples on the tank to use Speaking from experience here, I think the balance pipe needs to be bigger than a -6, and importantly, the two tanks need to be linked at the top to allow air to travel between the two tanks too, ensuring that the lowest point of that 'breather' is the point at which is meets both tanks. We had issues with this at first but overcame them with a bigger link pipe.
The top ones (currently capped off as per factory fuel set up) I am using as returns from the surge, one bottom one is a feed, and one bottom one is for the balance pipe.
CL GTR said:
Hey Alex, have you ever had your car on a dyno? I am in Sydney looking to buy an Ultima GTR with the 700hp American Speed engine and I was sent a dyno chart from the owner with it making a max of 366kw @ 5725rpm and dropping off to about 340kw @ 7005rpm. To me this seems quite low for a 700hp @ flywheel rated engine.
The one from TAS?My standard engine made like 340 rwkw as far as I can remember. Which is about right if you think standard engine is 505hp, plus the long tube headers, so maybe ~550hp. 550hp into kw = 410kw, take away 15-20% driveline loss and it's around 330rwkw +/-.
Can't see how a car with 700 fly wheel hp could possibly be making 366rwkw. 366 * 1.25 / 0.75 = 610hp at the flywheel.
PS - When I spoke to Gail when originally before buying my engine, he said "Modifications to 700 hp include, hand ported cylinder heads, custom camshaft, HD pushrods, PAC high lift valve springs, FAST fuel injection manifold and injectors, custom made 102mm drive wire throttle body, carbon fiber fuel rail covers."
CL GTR said:
Will be good to see what it pulls.
Are you ever going to take it to the strip?
Probably one day, yes. But I am building this car to smash out times are Philip Island.Are you ever going to take it to the strip?
845ste said:
Chris for me is not correct: see at http://www.hotrod.com/features/1507-20-ls1-intake-...
mid range is equal but edelbrock is better cheap
Open these two images in two tabs in your browsermid range is equal but edelbrock is better cheap
1. MSD: http://image.hotrod.com/f/133164278+w660+h495+cr1/...
2. Edelbrock: http://image.hotrod.com/f/133164110+w660+h495+cr1/...
Use your mouse and click between the two tabs to see the difference.
For a street car, the MSD is my choice. Consistently out performs the Edelbrock, and a lot more midrange power and torque over all.
And that's on a 6L, I am sure the difference will be even bigger on a 427ci.
Rev limiter set to 7400rpm. Would have gone to 7600rpm, but no point with power dropping off.
Video: https://www.youtube.com/watch?v=Q8JCyGTTYBA
That's three runs over the top of themselves. Second run has 2 degrees pulled out of it, third run had another degree pulled out of it. Very consistent, I'm happy.
Interesting that my engine is down on "dyno power" like the AS engine in Tasmania. I don't actually care how much power my car makes, if the AS engines rwkw dyno at 366 (as mentioned above) and I'm putting down 357, it's as good as a GTR720 to me as that's the engine they've got in that.
Now to lay down some lap times at Philip Island in two weeks time.
Video: https://www.youtube.com/watch?v=Q8JCyGTTYBA
That's three runs over the top of themselves. Second run has 2 degrees pulled out of it, third run had another degree pulled out of it. Very consistent, I'm happy.
Interesting that my engine is down on "dyno power" like the AS engine in Tasmania. I don't actually care how much power my car makes, if the AS engines rwkw dyno at 366 (as mentioned above) and I'm putting down 357, it's as good as a GTR720 to me as that's the engine they've got in that.
Now to lay down some lap times at Philip Island in two weeks time.
Edited by AlexCim on Tuesday 22 March 05:56
Yes - that's right.
Engine dyno figures follow an SAE procedure. I think it's hard to compare power figures if all cars are not on the same dyno. Plus, when you consider all different gearboxes, diffs, wheel spin, etc - hard to say anyway.
Really, I need to get on the same dyno as that other car from Tasmania to do a direct comparison.
Engine dyno figures follow an SAE procedure. I think it's hard to compare power figures if all cars are not on the same dyno. Plus, when you consider all different gearboxes, diffs, wheel spin, etc - hard to say anyway.
Really, I need to get on the same dyno as that other car from Tasmania to do a direct comparison.
Well, power is a calculated value from torque - so I don't think a torque graph would show anything useful really.
I have the Ultima LS7 exhaust - headers, pipes and mufflers. See the first pictures. Car is not FI, it's N/A.
After I left, he flattened out that fuel wave a bit. My research indicates that most LS7's are tuned for around 12.5 A/F. But it's about just giving the engine what it wants. The guy tuning it used to be lead mechanic for a Holden racing team and just tunes LS engines these days. His brief was "I am going to pump out lap after lap on a track" - so he went from there.
I have the Ultima LS7 exhaust - headers, pipes and mufflers. See the first pictures. Car is not FI, it's N/A.
After I left, he flattened out that fuel wave a bit. My research indicates that most LS7's are tuned for around 12.5 A/F. But it's about just giving the engine what it wants. The guy tuning it used to be lead mechanic for a Holden racing team and just tunes LS engines these days. His brief was "I am going to pump out lap after lap on a track" - so he went from there.
Look, it's almost impossible to tell anything unless things are compared exactly side by side.
To be honest, my car doesn't feel any faster or slower, but it's hard to tell on the road (because it's so fast and this isn't Germany). And last time I went to the track, I had road tyres, and a crappy fuel system. But I am not one to feel "difference" unless it's something big like a turbo change etc.
So I am going to track again in 3 weeks, so we will see what it lays down.
Then I'll go to strip in a few weeks after that and see what it does.
To be honest, my car doesn't feel any faster or slower, but it's hard to tell on the road (because it's so fast and this isn't Germany). And last time I went to the track, I had road tyres, and a crappy fuel system. But I am not one to feel "difference" unless it's something big like a turbo change etc.
So I am going to track again in 3 weeks, so we will see what it lays down.
Then I'll go to strip in a few weeks after that and see what it does.
02PRUV - You are putting in an ST6 right? The 044's are working fine now they're inside the surge tank - they are very quiet. If I had had to do it all again, I'd put a big link pipe. But now it's a problem because it's really hard to weld on another fitting with the tanks in situ. So I'm kinda screwed.
The -6 is working OK. But there are some funny buggers going on at the moment which I am investing and will return with results. I think one side may be filling up more... but, as I said, need to investigate.
Anyway, for now, I also blew my up my a/c compressor the other day...
The -6 is working OK. But there are some funny buggers going on at the moment which I am investing and will return with results. I think one side may be filling up more... but, as I said, need to investigate.
Anyway, for now, I also blew my up my a/c compressor the other day...
Edited by AlexCim on Wednesday 13th April 06:58
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