600 foot pounds of torque at the rear wheels (yipeee)
Discussion
LS1 and holden injectors are only rated at 28 lbs. For one year or so they were actually less then that so you definately need bigger injectors. 28lb items at 80% duty are no where near big enough imho.
Oh, are your knock sensors being activated at all? I hear good things about HP tuners.
Boosted.
>> Edited by Boosted LS1 on Friday 12th November 21:54
Oh, are your knock sensors being activated at all? I hear good things about HP tuners.
Boosted.
>> Edited by Boosted LS1 on Friday 12th November 21:54
[quote]Oh, are your knock sensors being activated at all? I hear good things about HP tuners[/quote]
Strange you should say that, as when tuning the car we found the knock sensors had been set out of range so they did not work!!!!!!
As a temp measure we reduced the spark table, but this is just a measure to save the engine until we can find out why they have removed the knock function....any ideas?
Strange you should say that, as when tuning the car we found the knock sensors had been set out of range so they did not work!!!!!!
As a temp measure we reduced the spark table, but this is just a measure to save the engine until we can find out why they have removed the knock function....any ideas?
As previously mentioned,not only spark but fueling.
What size are the injectors?
I have 42lb and still not large enough.At 500 + bhp the duty cycle was in excess of 80%. 'Will', make sure you have enough fuel as detonation at the power we make is enough to blow the engine.I am talking from experience,and i am now fitting 523cc (50lb) injectors to satisfy the demands.'KNOCK' will kill your engine.
What size are the injectors?
I have 42lb and still not large enough.At 500 + bhp the duty cycle was in excess of 80%. 'Will', make sure you have enough fuel as detonation at the power we make is enough to blow the engine.I am talking from experience,and i am now fitting 523cc (50lb) injectors to satisfy the demands.'KNOCK' will kill your engine.
Probably the best tried and tested injector upgrade would be the 60lb Mototrons. The LS1 guys in the US love them.
But I would consider fitting a proper fuel system..ie, a system with a return, and fuel press reg near the rail, referenced with boost pressure.
The stock system uses a static pressure, which does not change.
What sort of pump are you using ? Again, the US guys at that sort of power level would have a couple of Walbros in action or a single high rated pump.
Things like Boost A Pump can work, but arent really a proper fix. ( they simply increase pump voltage when needed )
I have 57lb Siemens inj, and Aeromotive rails and FPR, ad Pump for my engine, for when I eventually get it going. With hindsight, I would have bought the mototrons, purely as the Siemens, being the fat Bosch type injector didnt fit perfectly with the aeromotive fuel rails, although they would be fine with std LS1 type rails.
Not sure why they would remove the knock function ?? but as stated, if it is detonating, or knocking, or indeed running lean, it will spell disaster.
When on the Dyno, did Abbey monitor AFR's ?? I would expect any Dyno operator to do so. Do you have a printout of them ?
But I would consider fitting a proper fuel system..ie, a system with a return, and fuel press reg near the rail, referenced with boost pressure.
The stock system uses a static pressure, which does not change.
What sort of pump are you using ? Again, the US guys at that sort of power level would have a couple of Walbros in action or a single high rated pump.
Things like Boost A Pump can work, but arent really a proper fix. ( they simply increase pump voltage when needed )
I have 57lb Siemens inj, and Aeromotive rails and FPR, ad Pump for my engine, for when I eventually get it going. With hindsight, I would have bought the mototrons, purely as the Siemens, being the fat Bosch type injector didnt fit perfectly with the aeromotive fuel rails, although they would be fine with std LS1 type rails.
Not sure why they would remove the knock function ?? but as stated, if it is detonating, or knocking, or indeed running lean, it will spell disaster.
When on the Dyno, did Abbey monitor AFR's ?? I would expect any Dyno operator to do so. Do you have a printout of them ?
uk hsv said:
[quote]Oh, are your knock sensors being activated at all? I hear good things about HP tuners
Strange you should say that, as when tuning the car we found the knock sensors had been set out of range so they did not work!!!!!!
[/quote]
I have heard of people removing the knock function as they can be over sensitive and retard to much timing. Your engine has been changed so far from stock that this could be why but I can't really pass comment. It will also sound a lot different internally. Your engine will also go 'pop' in a nanosecond if you load it up with the wrong fuel & spark settings. The piston crowns are only some 5 mm thick on the top ring land, built to do a good job but to a n/a design brief. So, I'd take full advantage of any tuning set up/help you can find especially on the rollers
Love to hear it, must be really nice. Boosted.
Thanks again Brian, Stevie & Mike
I'll try & get the AFR's on site soon
When I ran the car with 50 Lb injectors (Bosch)initially they worked, when I removed cats and centre mufflers the car went too lean & went into safe mode and then changed the injectors to 30Lb which are in now.
Stevie, fuel surge tank fitted with Bosch M'Sport pump, considered fitting a regulator but they are problomatic apparently?
Boosted LS1 - I think the noise is totally awesome, but then that ois my opinion, not for the feignt hearted.
Hi Eric, thought you had been rather quiet of late, I take it that was a cheap joke re: tyres: LOL
Brian, would love to chat to you/meet up, any chance you could email me for your contact details: willbartlam@ntlworld.com
Will
>> Edited by V8HSV on Saturday 13th November 12:21
I'll try & get the AFR's on site soon
When I ran the car with 50 Lb injectors (Bosch)initially they worked, when I removed cats and centre mufflers the car went too lean & went into safe mode and then changed the injectors to 30Lb which are in now.
Stevie, fuel surge tank fitted with Bosch M'Sport pump, considered fitting a regulator but they are problomatic apparently?
Boosted LS1 - I think the noise is totally awesome, but then that ois my opinion, not for the feignt hearted.
Hi Eric, thought you had been rather quiet of late, I take it that was a cheap joke re: tyres: LOL
Brian, would love to chat to you/meet up, any chance you could email me for your contact details: willbartlam@ntlworld.com
Will
>> Edited by V8HSV on Saturday 13th November 12:21
Did you alter the cars programming when you removed the cats ??
The car needs the cats, so that the front and rear oxy sensors read properly, otherwise it will throw fault codes.
This is purely emission control related stuff, and shouldnt have effected WOT mixtures, although it could cause some part throttle driveability issues..
It would be very odd, for 50lb injectors under any circumstances to run lean compared to 30lb.
The only thing that can make a large injector appear to small, is if there are inadequacies in the fuel system elsewhere. ie fuel pump, or lines being restrictive, although pump is more likely.
Again, what way was the ecu programmed to cope with
A) first the swap from 30 to 50lb...
b) then back again ??
You CANNOT make a massive change like that, without re-mapping.
The car needs the cats, so that the front and rear oxy sensors read properly, otherwise it will throw fault codes.
This is purely emission control related stuff, and shouldnt have effected WOT mixtures, although it could cause some part throttle driveability issues..
It would be very odd, for 50lb injectors under any circumstances to run lean compared to 30lb.
The only thing that can make a large injector appear to small, is if there are inadequacies in the fuel system elsewhere. ie fuel pump, or lines being restrictive, although pump is more likely.
Again, what way was the ecu programmed to cope with
A) first the swap from 30 to 50lb...
b) then back again ??
You CANNOT make a massive change like that, without re-mapping.
HP Tuners should be able to sort and eliminate any fault codes too when re-mapped.
I assume you are aware of their forum.
www.hptuners.com/forum/YaBB.pl#gmv8tuning_cat
and some other worthwhile LS1 based forums
www.ls1tech.com/forums/index.php?
www.ls1.com.au/forum/forumdisplay.php?f=9
http://forums.corvetteforum.com/zeroforum?id=86
www.ls1gto.com/forums/index.php?
www.ls1.com/forums/index.php?s=b0f16603209609b44b59dce56fe51105&
www.z06vette.com/forums/index.php?
www.teamls1.com/phpBB/index.php
I assume you are aware of their forum.
www.hptuners.com/forum/YaBB.pl#gmv8tuning_cat
and some other worthwhile LS1 based forums
www.ls1tech.com/forums/index.php?
www.ls1.com.au/forum/forumdisplay.php?f=9
http://forums.corvetteforum.com/zeroforum?id=86
www.ls1gto.com/forums/index.php?
www.ls1.com/forums/index.php?s=b0f16603209609b44b59dce56fe51105&
www.z06vette.com/forums/index.php?
www.teamls1.com/phpBB/index.php
I've had some problems like this which were all fuel supply related. I think that if you increase the pressure you actually reduce the flow. That sounds strange but I'm sure I've come across this. In my case the car got fitted with a regulator, boost referenced and fitted to the rail with a return line. It also got fitted with a pump that could support 1000 hp at 45 psi or something similar. Then it got a remap. It wasn't using a stock ecu so there was plenty of scope. Sorting the fuel supply sorted the car in this instance.
I assumt thats over a couple of runs hence green line and red line ??
AFR's look safe, although very very rich below 2500rpm.
If its a full WOT run, Id like to see mid 12's there possibly even touching 13.0:1
Mid range is better from 2500rpm to 4500rpm, 11.5:1 is a good safe target.
Again, above 4500rpm it is very rich. Really you dont need or want to go richer than 11.0:1
from around 2500rpm upwards, Id like to see a good steady 11.5:1, there is more power to be gained above 4500rpm there for sure. Is there any missfires, or rough running up high ?
It would also be good to monitor AFR's on the road real time, as sometimes they can differ from on a dyno.
A lot of the time, I think they run leaner on the road, than on dyno.
There are definatley gains to be made all round there IMO.
What you have is safe, but Im amazed its making so much power on stock injectors, and not running lean.
Increasing the pressure can and does increase the flow, but only if the pump is capable of doing it at the higher pressures, which many cant, especially if you are already near its max flow..
There is one guy pushing near 1000bhp with 60lb Mototrons, but he is running almost a whopping 90psi line pressure.
Its amazing the injectors can handle that, but as I said, thats why the US guys love them. While it works for him, its not the correct way to do it.
AFR's look safe, although very very rich below 2500rpm.
If its a full WOT run, Id like to see mid 12's there possibly even touching 13.0:1
Mid range is better from 2500rpm to 4500rpm, 11.5:1 is a good safe target.
Again, above 4500rpm it is very rich. Really you dont need or want to go richer than 11.0:1
from around 2500rpm upwards, Id like to see a good steady 11.5:1, there is more power to be gained above 4500rpm there for sure. Is there any missfires, or rough running up high ?
It would also be good to monitor AFR's on the road real time, as sometimes they can differ from on a dyno.
A lot of the time, I think they run leaner on the road, than on dyno.
There are definatley gains to be made all round there IMO.
What you have is safe, but Im amazed its making so much power on stock injectors, and not running lean.
Increasing the pressure can and does increase the flow, but only if the pump is capable of doing it at the higher pressures, which many cant, especially if you are already near its max flow..
There is one guy pushing near 1000bhp with 60lb Mototrons, but he is running almost a whopping 90psi line pressure.
Its amazing the injectors can handle that, but as I said, thats why the US guys love them. While it works for him, its not the correct way to do it.
The main aim of the day was to find out what was wrong with the car and make it safe in the time we had (3hrs)
the reason for the drop off in A/F was unknown at the time of the dyno run, as I adjusted the fuel but could not bring it down!!!
After looking at the PCM I have found a ECT Multiplier which was coming into effect and so overiding my adjustments!!! (GM Make a very complex PCM)
The rich start to the run might have something to do with the VE table as it has not been adjusted yet on part throttle (may be next friday "Will") from what we have seen in the past the car is rich as seen from the LTFT......
I agree there is more power to come but only when I have looked into some strange PCM settings!!!!!
the reason for the drop off in A/F was unknown at the time of the dyno run, as I adjusted the fuel but could not bring it down!!!
After looking at the PCM I have found a ECT Multiplier which was coming into effect and so overiding my adjustments!!! (GM Make a very complex PCM)
The rich start to the run might have something to do with the VE table as it has not been adjusted yet on part throttle (may be next friday "Will") from what we have seen in the past the car is rich as seen from the LTFT......
I agree there is more power to come but only when I have looked into some strange PCM settings!!!!!
www.ls1tech.com/forums/showthread.php?t=200329&page=1&pp=20
Would be a bit nervous (LOL) at posting on this site due to nationality
Coulds this addtion make it the longest post here?
Lights the fuse and walks away....
>> Edited by V8HSV on Saturday 13th November 16:18
Would be a bit nervous (LOL) at posting on this site due to nationality
Coulds this addtion make it the longest post here?
Lights the fuse and walks away....
>> Edited by V8HSV on Saturday 13th November 16:18
Just to confirm. When you say "drop off in A/F" that actually imeans a huge increase in fuelling, not a decrease.
Just to clarify, as it sort of reads as if "drop off" indicates going lean.
A 90psi line pressure will put massive strains on all but the best of fuel pumps ( not to mention injectors as already stated )
The only pump available in the UK easily that I am aware of that could safely cope with such pressures, is the Bosch 044 8bar motorsport pump, but even it above 500bhp or so, is pushing it to the limit.
Just to clarify, as it sort of reads as if "drop off" indicates going lean.
A 90psi line pressure will put massive strains on all but the best of fuel pumps ( not to mention injectors as already stated )
The only pump available in the UK easily that I am aware of that could safely cope with such pressures, is the Bosch 044 8bar motorsport pump, but even it above 500bhp or so, is pushing it to the limit.
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