LS3 top end swap
Discussion
5 KPA = ~5% power..
The LS3 intake is supposed to be "ok" in stock form. Certainly way better than the LS2 and on a par with the old LS1 fast90.
There are flow numbers from US head porters supporting this. So Id be looking at the intake tract IMO.
If you have a 90mm throttle why use an 85mm maf!?
Why use a maf at all ?
Bottom line is 5kpa is a lot.
Run it with the stock intake and TB and no air intake (on the dyno) and see what KPA it pulls.
I recon that will give most of the lost air back.
The LS3 intake is supposed to be "ok" in stock form. Certainly way better than the LS2 and on a par with the old LS1 fast90.
There are flow numbers from US head porters supporting this. So Id be looking at the intake tract IMO.
If you have a 90mm throttle why use an 85mm maf!?
Why use a maf at all ?
Bottom line is 5kpa is a lot.
Run it with the stock intake and TB and no air intake (on the dyno) and see what KPA it pulls.
I recon that will give most of the lost air back.
I still have my 5" intake in the wings, sourced parts from intakes.com, similar to the hard core intake, it's a 4" to 5" elbow at the TB, short stretch to where the stock filter is with a 5" K&N cone filter with out MAF.
I have a LS7 slot MAF ready to install in the straight section, I did try to get MF to weld the bunk last year, but alas no alu tig welding. I've got an assortment of airflow straighteners too. i need to fit a T for the breather also. I want to maintain the MAF but without the restriction hence I'm trying 5". I want to keep the MAF for CL and LTFTs take care of any disparity between the two banks. I had a lot of success with simultaneous VE table and MAF calibration using EFILive, better results than AUTOVE.
If 5kPa = 5% down, that would be around 380rwhp, g/cyl tells a different story, up 15% at peak.
I've not thought about a FAST intake or CNC heads, just want the most from installed cam and the stock heads, if I get to 500FWHP, I'd be happy considering the out lay. If I want more, I'd consider FI now, I like the crate LSA with a cam, but it won't fit.
I'm still working abroad, probably another two years, all on my to do list.
I have a LS7 slot MAF ready to install in the straight section, I did try to get MF to weld the bunk last year, but alas no alu tig welding. I've got an assortment of airflow straighteners too. i need to fit a T for the breather also. I want to maintain the MAF but without the restriction hence I'm trying 5". I want to keep the MAF for CL and LTFTs take care of any disparity between the two banks. I had a lot of success with simultaneous VE table and MAF calibration using EFILive, better results than AUTOVE.
If 5kPa = 5% down, that would be around 380rwhp, g/cyl tells a different story, up 15% at peak.
I've not thought about a FAST intake or CNC heads, just want the most from installed cam and the stock heads, if I get to 500FWHP, I'd be happy considering the out lay. If I want more, I'd consider FI now, I like the crate LSA with a cam, but it won't fit.
I'm still working abroad, probably another two years, all on my to do list.
Gelf VXR said:
Thinking about it, in stock form, dynamic fuelling, the PCM refers to the MAF and VE table up to some RPM, I forget now, over that RPM it relies on MAF only. Closed or open loop, failing the MAF will result in PCM referring only the VE table, speed density.
I just happened to look at this value the other day, E40 stock it goes MAF only above 3,600 rpm. Once it's gone MAF only, has to drop below 3,500 to go back to 'dynamic air mode' as they've called it in EFI Live 
KMud, I've had LTFT off since getting EFI Live. If you're going to be tuning the tables to accurately reflect airflow anyway, not much they're going to do for you, the STFT should have the weight to cope with the small short term changes.
Plus LTFT are added when going WOT (PE mode) so can help confuse your PE tuning if you don't realise they're on
SturdyHSV said:
Gelf VXR said:
Thinking about it, in stock form, dynamic fuelling, the PCM refers to the MAF and VE table up to some RPM, I forget now, over that RPM it relies on MAF only. Closed or open loop, failing the MAF will result in PCM referring only the VE table, speed density.
I just happened to look at this value the other day, E40 stock it goes MAF only above 3,600 rpm. Once it's gone MAF only, has to drop below 3,500 to go back to 'dynamic air mode' as they've called it in EFI Live KMud, I've had LTFT off since getting EFI Live. If you're going to be tuning the tables to accurately reflect airflow anyway, not much they're going to do for you, the STFT should have the weight to cope with the small short term changes.
Plus LTFT are added when going WOT (PE mode) so can help confuse your PE fuelling
k you guys are talking about 
SturdyHSV said:
I just happened to look at this value the other day, E40 stock it goes MAF only above 3,600 rpm. Once it's gone MAF only, has to drop below 3,500 to go back to 'dynamic air mode' as they've called it in EFI Live
KMud, I've had LTFT off since getting EFI Live. If you're going to be tuning the tables to accurately reflect airflow anyway, not much they're going to do for you, the STFT should have the weight to cope with the small short term changes.
Plus LTFT are added when going WOT (PE mode) so can help confuse your PE tuning if you don't realise they're on
I've got them off too (amongst other things), just wasn't sure if there was a long-term benefit in getting them back on (like bank levelling as I think Gelf was saying). My STFTs look good.KMud, I've had LTFT off since getting EFI Live. If you're going to be tuning the tables to accurately reflect airflow anyway, not much they're going to do for you, the STFT should have the weight to cope with the small short term changes.
Plus LTFT are added when going WOT (PE mode) so can help confuse your PE tuning if you don't realise they're on
Anyway, SD CL here
KMud said:
I've got them off too (amongst other things), just wasn't sure if there was a long-term benefit in getting them back on (like bank levelling as I think Gelf was saying). My STFTs look good.
Anyway, SD CL here
I'm thinking of going SD too, going to try running through some CALC.VET once my WB is installed to get the MAF correct and VE table correct, if I then get bored, may try chucking the MAF out. Already got a separate IAT sensor anyway because of the OTR CAI.Anyway, SD CL here
And yes, I'm using acronyms just for the sake of it now, sorry Jonn!
MyM8V8 said:
Better than E40 AutoVE? You wrote the manual???
The problem with AutoVE I always had was when I re enabled closed loop and MAF, LTFTs were all over the place. Even after doing a MAF calibration I wasn't happy. I put it down to no two logs being the same, if your going to calibrate the VE table and the MAF sensor, you should use the same log data, I found a practical way to do that which yielded tight LTFT,s. In effect your calibrating the engine airflow to the injector flow. Your MAF might be calibrated from the factory, however logic says it should be calibrated to the engine variables and the fixed injector flow tables, not forgetting the calibration accuracy of your WB O2's. I don't know of any method to auto calibrate the injector flow tables to the airflow data from a calibrated MAF?On the MAF vs speed density argument, I always favoured MAF because I thought it was required for closed loop, doh.
I changed my tune now, excuse the pun, if it's a restriction, out it comes. I still want to experiment with MAF in my larger intake, I have had dynamic fuelling enabled 800 ~ 6400 on my stock intake, speed density...., MAF enabled lol
Edited by Gelf VXR on Friday 14th March 23:16
I dream of staying SD with my Jenvey's I'm hoping the MAP sensor will get a enough of a signal to aid in the initial setup (so I can drive it 30 miles to the dyno!). I really should try to start it this weekend as all the mechanical bits are done bar the air boxes.
I believe the only problem with logging on the road is that ideally you want to do them in exactly the same conditions each time. Then on hotter/colder days you build the correction tables based on the logged data. Rather than keep applying changes to the main VE.
I'll try doing it that way this time. However so long as I keep the logs I can always try both ways and see which gives the best LTFT's.
I believe the only problem with logging on the road is that ideally you want to do them in exactly the same conditions each time. Then on hotter/colder days you build the correction tables based on the logged data. Rather than keep applying changes to the main VE.
I'll try doing it that way this time. However so long as I keep the logs I can always try both ways and see which gives the best LTFT's.
Gelf VXR said:
MyM8V8 said:
Better than E40 AutoVE? You wrote the manual???
The problem with AutoVE I always had was when I re enabled closed loop and MAF, LTFTs were all over the place. Even after doing a MAF calibration I wasn't happy. I put it down to no two logs being the same, if your going to calibrate the VE table and the MAF sensor, you should use the same log data, I found a practical way to do that which yielded tight LTFT,s. In effect your calibrating the engine airflow to the injector flow. Your MAF might be calibrated from the factory, however logic says it should be calibrated to the engine variables and the fixed injector flow tables, not forgetting the calibration accuracy of your WB O2's. I don't know of any method to auto calibrate the injector flow tables to the airflow data from a calibrated MAF?On the MAF vs speed density argument, I always favoured MAF because I thought it was required for closed loop, doh.
I changed my tune now, excuse the pun, if it's a restriction, out it comes. I still want to experiment with MAF in my larger intake, I have had dynamic fuelling enabled 800 ~ 6400 on my stock intake, speed density...., MAF enabled lol
Edited by Gelf VXR on Friday 14th March 23:16
Gelf VXR said:
In effect your calibrating the engine airflow to the injector flow. Your MAF might be calibrated from the factory, however logic says it should be calibrated to the engine variables and the fixed injector flow tables, not forgetting the calibration accuracy of your WB O2's. I don't know of any method to auto calibrate the injector flow tables to the airflow data from a calibrated MAF?
On the MAF vs speed density argument, I always favoured MAF because I thought it was required for closed loop, doh.
2. Exactly why I ditched the MAF.On the MAF vs speed density argument, I always favoured MAF because I thought it was required for closed loop, doh.
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