PMO ITB's, DC 43 cam, JIC, Electromotive TEC3R, etc
07-05-2011, 01:57 AM
#46
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Just came back from the shop and found out that it was plus 44rwhp and not 50. Well still happy with the result. We are still tuning the car. Looking at the hp curve, we are thinking of raising the rev limit a bit more since hp seems still to be climbing up to 6.6k.
They just moved the dyno and are doing improvements to the shop hence the car is dusty. If you noticed from the vid, he seems to let off early. This is a 4th gear pull.
Pics of the dyno sheets.
Note the curve drops right at 6.6k, talking to Andy T. from flatsixonline and he says raising it to 7k should be ok. Andy is such a great guy giving free advice.
Here is the torque curve. Notice how quickly torque comes in at 2k. It shows that is even more torquier than stock! Cant wait to drive it. We are waiting for the PLX O2 sensors to come in so that we can street tune properly. Right now, one bank is reading lean. Better safe than sorry.
They just moved the dyno and are doing improvements to the shop hence the car is dusty. If you noticed from the vid, he seems to let off early. This is a 4th gear pull.
Pics of the dyno sheets.
Note the curve drops right at 6.6k, talking to Andy T. from flatsixonline and he says raising it to 7k should be ok. Andy is such a great guy giving free advice.
Here is the torque curve. Notice how quickly torque comes in at 2k. It shows that is even more torquier than stock! Cant wait to drive it. We are waiting for the PLX O2 sensors to come in so that we can street tune properly. Right now, one bank is reading lean. Better safe than sorry.
07-05-2011, 03:37 AM
#47
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Thanks for posting those.
I think you should lift the limiter. I know you have Asco springs and ti retainers with solid lifters and could probably venture to 7000 rpm however I would go to 6800 or 6850 and see if the power has dropped off at that time. Theres really not much point going beyond the power and as the vehicle is new to you the history of the egine is relatively unknown at it would be a shame to stretch her too far and find you have to do a bottom end job. IMHO of course.
Ive posted my Sept 2010 run. Its my best run to date. Its has TCF 1.09 (9%). Remove the TCF for peak. 264 hp/233lbft. Ive supplied the raw 1:1 data for you too. I think this could be useful to compare with your operator. Drive ratio. Gear. temps and AFRs. This run was done on a standard Steve Wong chip which was then shipped back to him for fettling the AFRs. They came back very tidy averaging around 0.90 - but it didnt affect readings beyond temperature/fuel/humidity related variances. The original chip actually produced 2-3 hp more and similar difference in torque due to the almost 8 celcius temp diff and 25% humidity diff between the runs.
Im not sure but it may bbe of use to you. Engine was factory standard never opened 68k km, with SW chip, Dach X pipes, RSR mufflers, and RS LWFC. MAF has just been replaced with new.
The gains you have made are reasonable given the mods you have made (although I cant comment on value as I have no idea what it has cost). You have almost made 50 hp at the crank (10% loss). The torque increase not as much as I would have expected. Looks like 22lbft at the crank (10% loss).
It may simply be there is something at play here. Your base run before modifications is very low for a NVR 993. Its 243 bhp approx for crank using 10%. Either the dyno runs are done with a different ratio or gear, they are SAE or maybe there is something odd with the health of the engine. It doesnt feel right to me. Ive been through a dozen 993 Dynapak dynos and although they all differ something "feels" off with your base and thus after mod results.
My guess is its the Dyno mostly and the engine as a possiblility (looking at Geoffreys 964 Motec land cam conversion ast year and Colins work on the Motec 964RS in the article I posted link to give you an idea of what a very mild RS type cam, new hi flow injectors with factory Pleneums on Motec with catless exhaust should give power and tq wise). With ITBs and the DC41 using the custom progrmmable ECU you shuld be exceeding those figures. Somethings not quite right. Maybe try another dyno after all your tuning is completed....
Not trying to take anything away from you - Ive been down the same path last month when I had teh Cams done and made less power across most of the rev band. If someone had have suggested checking the coil I would have saved alot of stress and money going LINK. Th efact is though that I cant guarantee that the coil would have fixed teh issue until later in the week when the new one is installed - and if it wasnt repsible for the drop in power then Im leaning on big injectors and the LINK ecu and some very experienced tuning guys to make up alot of ground between my old figures with very midly warned engine and by EXPECTATIONS after having spend a crap load of cash on leads, plugs, coils, ECUs, cams, solid lifters, hi flow injectors and 8+ hrs of tuning plus all the labour to install said items! Heck I DESERVE 320bhp minimum plus 285 lbft from this conversion! But I doubt Ill get it!
Cheers
M
I think you should lift the limiter. I know you have Asco springs and ti retainers with solid lifters and could probably venture to 7000 rpm however I would go to 6800 or 6850 and see if the power has dropped off at that time. Theres really not much point going beyond the power and as the vehicle is new to you the history of the egine is relatively unknown at it would be a shame to stretch her too far and find you have to do a bottom end job. IMHO of course.
Ive posted my Sept 2010 run. Its my best run to date. Its has TCF 1.09 (9%). Remove the TCF for peak. 264 hp/233lbft. Ive supplied the raw 1:1 data for you too. I think this could be useful to compare with your operator. Drive ratio. Gear. temps and AFRs. This run was done on a standard Steve Wong chip which was then shipped back to him for fettling the AFRs. They came back very tidy averaging around 0.90 - but it didnt affect readings beyond temperature/fuel/humidity related variances. The original chip actually produced 2-3 hp more and similar difference in torque due to the almost 8 celcius temp diff and 25% humidity diff between the runs.
Im not sure but it may bbe of use to you. Engine was factory standard never opened 68k km, with SW chip, Dach X pipes, RSR mufflers, and RS LWFC. MAF has just been replaced with new.
The gains you have made are reasonable given the mods you have made (although I cant comment on value as I have no idea what it has cost). You have almost made 50 hp at the crank (10% loss). The torque increase not as much as I would have expected. Looks like 22lbft at the crank (10% loss).
It may simply be there is something at play here. Your base run before modifications is very low for a NVR 993. Its 243 bhp approx for crank using 10%. Either the dyno runs are done with a different ratio or gear, they are SAE or maybe there is something odd with the health of the engine. It doesnt feel right to me. Ive been through a dozen 993 Dynapak dynos and although they all differ something "feels" off with your base and thus after mod results.
My guess is its the Dyno mostly and the engine as a possiblility (looking at Geoffreys 964 Motec land cam conversion ast year and Colins work on the Motec 964RS in the article I posted link to give you an idea of what a very mild RS type cam, new hi flow injectors with factory Pleneums on Motec with catless exhaust should give power and tq wise). With ITBs and the DC41 using the custom progrmmable ECU you shuld be exceeding those figures. Somethings not quite right. Maybe try another dyno after all your tuning is completed....
Not trying to take anything away from you - Ive been down the same path last month when I had teh Cams done and made less power across most of the rev band. If someone had have suggested checking the coil I would have saved alot of stress and money going LINK. Th efact is though that I cant guarantee that the coil would have fixed teh issue until later in the week when the new one is installed - and if it wasnt repsible for the drop in power then Im leaning on big injectors and the LINK ecu and some very experienced tuning guys to make up alot of ground between my old figures with very midly warned engine and by EXPECTATIONS after having spend a crap load of cash on leads, plugs, coils, ECUs, cams, solid lifters, hi flow injectors and 8+ hrs of tuning plus all the labour to install said items! Heck I DESERVE 320bhp minimum plus 285 lbft from this conversion! But I doubt Ill get it!
Cheers
M
07-05-2011, 06:55 AM
#48
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Just spoke to Andy T from flatsixonline and he said my gain is in-line with the mods. I agree with him that the best use of the dyno is to quantify whatever gains were seen from the mods. But ultimately, he mentions, its the responsiveness of the car to driver inputs. Like I mentioned earlier, two 993s were dynoed recently. One put out 210 rwhp after tuning from Tommy and the other was 209 rwhp after putting a Steve W chip.
My brothers 997 mk1 GT3 RS put out 350rwhp. His car has only less than 10k kms so it is a fresh car. Using simple math, I could be wrong but anyway, deducting his 350rwhp from my 267rwhp gives 83. After putting in drivetrain loss, and deducting it from his 415 rated hp, it puts me somewhere between 320-330 crank hp. Which is where I should be.
Like what some guys with TT kits posted, their dyno results also appeared low bec of atmospheric conditions.
Even if I dyno it in a dynojet, the nos will appear similar. That is from my experience with Hondas using that dynojet. The nos always appeared weaker than what is expected from the States.
Thanks for the inputs though. We are now balancing again the ITBs as some banks appear leaner than the other. So the tuning process is still on-going!
I would like to think of the project as building sort of a mechanical work of art. The sound of the ITBs, the cam, the exhaust, and how it translates to the cars response, it all sums up to what I am aiming for.
Will keep you posted.
My brothers 997 mk1 GT3 RS put out 350rwhp. His car has only less than 10k kms so it is a fresh car. Using simple math, I could be wrong but anyway, deducting his 350rwhp from my 267rwhp gives 83. After putting in drivetrain loss, and deducting it from his 415 rated hp, it puts me somewhere between 320-330 crank hp. Which is where I should be.
Like what some guys with TT kits posted, their dyno results also appeared low bec of atmospheric conditions.
Even if I dyno it in a dynojet, the nos will appear similar. That is from my experience with Hondas using that dynojet. The nos always appeared weaker than what is expected from the States.
Thanks for the inputs though. We are now balancing again the ITBs as some banks appear leaner than the other. So the tuning process is still on-going!
I would like to think of the project as building sort of a mechanical work of art. The sound of the ITBs, the cam, the exhaust, and how it translates to the cars response, it all sums up to what I am aiming for.
Will keep you posted.
07-05-2011, 07:50 AM
#49
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Hi Camlob.
I totally agree with regards to driveability. From the beginning that has been one of my key goals as previously stated. That article on the Motec 964RS really stresses the point....
If your brothers 997.1 GT3 is posting 350 rwhp on the same dynapak in similar atmo conditions then your reasoning regards the low numbers that dyno is producing is sound.
However you drive train loss factor of 18% isnt. The Dynapak chassis Dyno is proven back to back against engine Dynos in NZ where it is designed and built to loose far less than 18% RW against Crank in our application. If you are running a low mass drive train (aka LWFC, single belt alternator pulley, dual crank pulley) in a 2WD config with inline drivetrain and rear engine config you will be talking 9-12% most likely depending on the vehicle and gear sets. My shop using their engine dyno show 9% loss against their Dynapak 5000 on a 2010 V8 touring race car. They estimate 10% on 911 which is backed by our PCNZ Bridgestone race series published handicap specs which require Dynapak TCF of 1:1.10 for all cars entered in the national series. Ive seen some use 12% for a 2WD 964 running DMFW and stock pulleys and belts but some here believe thats perhaps a fraction ambitious. Atmosphere cannot affect drive train loss. Its a mark up function on RW numbers. Essentially its the majic number but with the hub mounted system tested against a engine dyno its a lot narrower variance metric than for many other types of dyno.
If your brothers car is making 350 rwhp on the same dyno you are using then hes making closer 385 bhp crank assuming hes at factory spec and adduming those cars deliver factory published output generally which I believe they do. Thats using a 10% TCF. I assume again you use the same 98 RON or similar type fuel etc
If others are getting claimed 320 bhp/290+lbft crank from a stock 964RS on Motec with only a change of injectors a MAP sensor, a TPS (as the 964 is more rudimentary than the 993 in this regard) and a cat delete bypass then given your engine and modfications (44lb injectors, agressive cam, ITBs, ECU) you are getting at least the same as that and I would think more assuming the tuning is right. Id say that dyno is reading low and the TCF is too high as a result. It makes sense as your RW current numbers are running roughly the same as my RW numbers when I was factory stock with just a massaged SW chip, cat delete pipes and RSR mufflers assuming our runs are in the same gear (4th) with the same ratio set on the Dynapak. I believe my numbers are fairly accurate afterall the factory unit makes 272 and 243lb and I posted 287 and 255lb using a 9% mark up after chip, cat X pass and freer flowing mufflers and LWFC. Thats only 15 hp and 12 lb improvement even if 9% is too conservative we are still talking 18 and 13.5lb with 10% TCF up from factory which seems pretty fair for those mods.
I think once your final tuning is complete and spot on you will be making closer to 330 bhp crank definately. That makes sense. The torque figures will probably be around 275-280lbft. The torque seems a bit low but that could be the exhaust config. with ITBs. Colin and one of the guys supporting the original 993 cup teams made mention that some equal length header configs will drop torque for bhp in a RL post somewhere...
As for me the jury is out. Im keeping my fingers firmly crossed for next week and Ill post the charts. Im hoping for at least 285 RWbhp and 250 RWlbft ( say 310 bhp and 275lb with 10% TCF) but Im at the mercy of the Gods of Speed to be fair! Thats 22 bhp up and 17lbft on the posted tables in this thread. Thats about half the BHP increase you got with the benefit of ITBs and much wilder cams but about the same increase in torque. That will do me! Surely thats possible with new cams, timing, injectors ECU and good tuning. I hope so otherwise its been an expensive hunt for ellusive power !!
Keep up the good work!
I totally agree with regards to driveability. From the beginning that has been one of my key goals as previously stated. That article on the Motec 964RS really stresses the point....
If your brothers 997.1 GT3 is posting 350 rwhp on the same dynapak in similar atmo conditions then your reasoning regards the low numbers that dyno is producing is sound.
However you drive train loss factor of 18% isnt. The Dynapak chassis Dyno is proven back to back against engine Dynos in NZ where it is designed and built to loose far less than 18% RW against Crank in our application. If you are running a low mass drive train (aka LWFC, single belt alternator pulley, dual crank pulley) in a 2WD config with inline drivetrain and rear engine config you will be talking 9-12% most likely depending on the vehicle and gear sets. My shop using their engine dyno show 9% loss against their Dynapak 5000 on a 2010 V8 touring race car. They estimate 10% on 911 which is backed by our PCNZ Bridgestone race series published handicap specs which require Dynapak TCF of 1:1.10 for all cars entered in the national series. Ive seen some use 12% for a 2WD 964 running DMFW and stock pulleys and belts but some here believe thats perhaps a fraction ambitious. Atmosphere cannot affect drive train loss. Its a mark up function on RW numbers. Essentially its the majic number but with the hub mounted system tested against a engine dyno its a lot narrower variance metric than for many other types of dyno.
If your brothers car is making 350 rwhp on the same dyno you are using then hes making closer 385 bhp crank assuming hes at factory spec and adduming those cars deliver factory published output generally which I believe they do. Thats using a 10% TCF. I assume again you use the same 98 RON or similar type fuel etc
If others are getting claimed 320 bhp/290+lbft crank from a stock 964RS on Motec with only a change of injectors a MAP sensor, a TPS (as the 964 is more rudimentary than the 993 in this regard) and a cat delete bypass then given your engine and modfications (44lb injectors, agressive cam, ITBs, ECU) you are getting at least the same as that and I would think more assuming the tuning is right. Id say that dyno is reading low and the TCF is too high as a result. It makes sense as your RW current numbers are running roughly the same as my RW numbers when I was factory stock with just a massaged SW chip, cat delete pipes and RSR mufflers assuming our runs are in the same gear (4th) with the same ratio set on the Dynapak. I believe my numbers are fairly accurate afterall the factory unit makes 272 and 243lb and I posted 287 and 255lb using a 9% mark up after chip, cat X pass and freer flowing mufflers and LWFC. Thats only 15 hp and 12 lb improvement even if 9% is too conservative we are still talking 18 and 13.5lb with 10% TCF up from factory which seems pretty fair for those mods.
I think once your final tuning is complete and spot on you will be making closer to 330 bhp crank definately. That makes sense. The torque figures will probably be around 275-280lbft. The torque seems a bit low but that could be the exhaust config. with ITBs. Colin and one of the guys supporting the original 993 cup teams made mention that some equal length header configs will drop torque for bhp in a RL post somewhere...
As for me the jury is out. Im keeping my fingers firmly crossed for next week and Ill post the charts. Im hoping for at least 285 RWbhp and 250 RWlbft ( say 310 bhp and 275lb with 10% TCF) but Im at the mercy of the Gods of Speed to be fair! Thats 22 bhp up and 17lbft on the posted tables in this thread. Thats about half the BHP increase you got with the benefit of ITBs and much wilder cams but about the same increase in torque. That will do me! Surely thats possible with new cams, timing, injectors ECU and good tuning. I hope so otherwise its been an expensive hunt for ellusive power !!
Keep up the good work!
07-05-2011, 09:25 AM
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A pic of the engine with the air cleaners on. I think it will look much better with the ITG filters on! Ill install it one day when it gets home. They will be coming off for more ITB balancing. I had the heater cover customized to seal the hole and painted it red. I should have painted the fan blade!
07-05-2011, 06:49 PM
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07-06-2011, 04:36 PM
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Actually, Porsche perfected ITB's in 1969 with their Bosch Mechanical Fuel Injection (only got away from it for fuel economy and emissions concerns - they used worse systems for decades).
07-06-2011, 04:38 PM
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Actually, Porsche perfected it with the 917 Le Mans racer and 1969 911E and 911S, etc. with Bosch Mechanical Fuel Injection (went with worse systems for decades due to emissions and mileage concerns).
Last edited by GrantG; 03-10-2013 at 11:18 PM.
07-06-2011, 07:03 PM
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Thanks for the pic! Yeah I pm'd Bill Verburg and he told me that most racing RSR's and all the 9's from 906 to the 917 used ITB's. You guys definitely have deeper knowledge on these cars!
07-07-2011, 12:45 AM
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A better pic of the torque dyno sheet. Didnt realize the first one was so blurry. Torque begins quite early, surprisingly. Sweetspot seems to be from 5k to 7k rpm. Ill be raising my limit to 7k. We just finished synchronizing the ITBs and are waiting for new PLX gauge to show the two banks AFRs. So far we are getting a lean bank on one side, hence we balanced the ITBs again.
07-13-2011, 08:46 AM
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Oh boy, we found out the cause of the off-balance of the afr's. I have weak cr on some cylinders. This project seems it will take longer than expected.
I am thinking of a 4l kit. From my research, the 3.8l kit is not cost effective. I know I have to machine the cases, but I guess it will be worth it.
According to Charles Navarro at LN Eng, he says stock rods will do for street car. I am still exploring the idea of Pauter rods. But I want to keep costs down since I have spent so much already.
I understand that the stock head will flow up to 385hp, so does that mean I dont need RS valves?
I think the very least I will get ARP rod bolts.
So my dilemma is, should I need after market rods and RS valves. I think with the good cr, my rwhp should jump at the very least. Then to add displacement would be even better.
I am not targetting 385 hp, I will be happy with 350 hp actually.
What do you guys think about the rods and valves?
I am thinking of a 4l kit. From my research, the 3.8l kit is not cost effective. I know I have to machine the cases, but I guess it will be worth it.
According to Charles Navarro at LN Eng, he says stock rods will do for street car. I am still exploring the idea of Pauter rods. But I want to keep costs down since I have spent so much already.
I understand that the stock head will flow up to 385hp, so does that mean I dont need RS valves?
I think the very least I will get ARP rod bolts.
So my dilemma is, should I need after market rods and RS valves. I think with the good cr, my rwhp should jump at the very least. Then to add displacement would be even better.
I am not targetting 385 hp, I will be happy with 350 hp actually.
What do you guys think about the rods and valves?
07-13-2011, 09:45 AM
#58
Oh boy, we found out the cause of the off-balance of the afr's. I have weak cr on some cylinders. This project seems it will take longer than expected.
I am thinking of a 4l kit. From my research, the 3.8l kit is not cost effective. I know I have to machine the cases, but I guess it will be worth it.
According to Charles Navarro at LN Eng, he says stock rods will do for street car. I am still exploring the idea of Pauter rods. But I want to keep costs down since I have spent so much already.
I understand that the stock head will flow up to 385hp, so does that mean I dont need RS valves?
I think the very least I will get ARP rod bolts.
So my dilemma is, should I need after market rods and RS valves. I think with the good cr, my rwhp should jump at the very least. Then to add displacement would be even better.
I am not targetting 385 hp, I will be happy with 350 hp actually.
What do you guys think about the rods and valves?
I am thinking of a 4l kit. From my research, the 3.8l kit is not cost effective. I know I have to machine the cases, but I guess it will be worth it.
According to Charles Navarro at LN Eng, he says stock rods will do for street car. I am still exploring the idea of Pauter rods. But I want to keep costs down since I have spent so much already.
I understand that the stock head will flow up to 385hp, so does that mean I dont need RS valves?
I think the very least I will get ARP rod bolts.
So my dilemma is, should I need after market rods and RS valves. I think with the good cr, my rwhp should jump at the very least. Then to add displacement would be even better.
I am not targetting 385 hp, I will be happy with 350 hp actually.
What do you guys think about the rods and valves?
But before your brain goes into money spending overdrive on 4L kits and rods I'd start off with a proper leak down test FIRST to establish where your engine is exactly loosing compression.
i.e. are the cilinders (pistons/rings/barrels) to blame OR is it lost in the heads (valves leaking/cilinder head studs snapped/heads warped).
Could be something relatively easy to fix such as a worn valve/guide.....
Good luck!
PS in case you do decide on a full blown rebuild with increased displacement go for the rods as well, you'll hardly find the costs of these back in the total package of things....
07-13-2011, 10:21 AM
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That s*cks! Especially after having spent so much time and $ on the ITB setup in the first place....
But before your brain goes into money spending overdrive on 4L kits and rods I'd start off with a proper leak down test FIRST to establish where your engine is exactly loosing compression.
i.e. are the cilinders (pistons/rings/barrels) to blame OR is it lost in the heads (valves leaking/cilinder head studs snapped/heads warped).
Could be something relatively easy to fix such as a worn valve/guide.....
Good luck!
PS in case you do decide on a full blown rebuild with increased displacement go for the rods as well, you'll hardly find the costs of these back in the total package of things....
But before your brain goes into money spending overdrive on 4L kits and rods I'd start off with a proper leak down test FIRST to establish where your engine is exactly loosing compression.
i.e. are the cilinders (pistons/rings/barrels) to blame OR is it lost in the heads (valves leaking/cilinder head studs snapped/heads warped).
Could be something relatively easy to fix such as a worn valve/guide.....
Good luck!
PS in case you do decide on a full blown rebuild with increased displacement go for the rods as well, you'll hardly find the costs of these back in the total package of things....
So I should go for rods? Well the pistons will be lighter than the stock pistons. Wishful thinking that maybe stock rods are ok.
07-13-2011, 05:02 PM
#60
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Camlob,
I feel your pain!
I commissioned an aftermarket ECU and tuning due to rough idle, stalling and my DC21 cams not making the power I had hoped (infact lost power most of the power band on the dyno by a small amount).
Turns out during the ECU install and testing they discover one of my coils has been down since the cams were installed! Guess what? Flew in a new coil, installed it, car now doesnt stall, idle is normal and the car is making more power than before the cam install! And thats while its still on the motornics system before switching to the ECU! i.e. had not had a failed coil pack I would not have spent the time and money under taking the aftermarket ECU project as I would have had no reason to and would have been happy with the output of the new cams!
As it stands the new ECU is being put into service today on the dyno and the tuning begins. Ill have some charts to post by the weekend I hope....
I did a CR test as part of the Cam install before we dropped the engine. The figures were all good. This was to establish the condition of the heads and pistons before we opened up. I did alot of research on CR first.
I tend to agree evoderby. Before you throw more good money into this project get a full set of data. Leakdown and compression on that engine. Post it on this board and get some feedback on what may be causing your issues. Rushing into a bottom end recondition or top end upgrade sounds silly right now. Frankly I dont think the 3.8 kit makes enough power to be worth it so I see your logic on the 4.0l kit - but again thats a real large outlay for maybe 30hp best and the only people I know that have done this are SERIOUS track guys who race. For a street car and for a road weight 993 I think this really is the least return per hp for your buck. 9M can get 325 bhp from a Motec upgrade on a 964RS engine with proper tuning and new injectors, freer flowing exhaust etc without even going more aggressive with the cams. The head you have and valves are good for at least 350 bhp and if you didnt have the CR issues you might be getting close already with a properly claibrated ECU and good health engine.
If it were me run the tests, poll the board, take lots of advice and if its something simple like rings or valve seals or guides Id take the head off and just get those sorted and then tune it perfectly to get the most out of what youve spent.
I think youd be suprised. You figures looked low to me and this could be (probably is) the reason. Like my coil pack such a simple and inexpensive part can cause the engine to loose timing and behave off peak. Id had saved a lot of money if I had have sat back and tested everything to make sure all was good before embarking on the ECU. As it stands Im really glad I went with the ECU as I hope it will really improve the cars response and also power etc but its always expensive this learning.....
Best of luck and keep us posted.
Cheers
M
I feel your pain!
I commissioned an aftermarket ECU and tuning due to rough idle, stalling and my DC21 cams not making the power I had hoped (infact lost power most of the power band on the dyno by a small amount).
Turns out during the ECU install and testing they discover one of my coils has been down since the cams were installed! Guess what? Flew in a new coil, installed it, car now doesnt stall, idle is normal and the car is making more power than before the cam install! And thats while its still on the motornics system before switching to the ECU! i.e. had not had a failed coil pack I would not have spent the time and money under taking the aftermarket ECU project as I would have had no reason to and would have been happy with the output of the new cams!
As it stands the new ECU is being put into service today on the dyno and the tuning begins. Ill have some charts to post by the weekend I hope....
I did a CR test as part of the Cam install before we dropped the engine. The figures were all good. This was to establish the condition of the heads and pistons before we opened up. I did alot of research on CR first.
I tend to agree evoderby. Before you throw more good money into this project get a full set of data. Leakdown and compression on that engine. Post it on this board and get some feedback on what may be causing your issues. Rushing into a bottom end recondition or top end upgrade sounds silly right now. Frankly I dont think the 3.8 kit makes enough power to be worth it so I see your logic on the 4.0l kit - but again thats a real large outlay for maybe 30hp best and the only people I know that have done this are SERIOUS track guys who race. For a street car and for a road weight 993 I think this really is the least return per hp for your buck. 9M can get 325 bhp from a Motec upgrade on a 964RS engine with proper tuning and new injectors, freer flowing exhaust etc without even going more aggressive with the cams. The head you have and valves are good for at least 350 bhp and if you didnt have the CR issues you might be getting close already with a properly claibrated ECU and good health engine.
If it were me run the tests, poll the board, take lots of advice and if its something simple like rings or valve seals or guides Id take the head off and just get those sorted and then tune it perfectly to get the most out of what youve spent.
I think youd be suprised. You figures looked low to me and this could be (probably is) the reason. Like my coil pack such a simple and inexpensive part can cause the engine to loose timing and behave off peak. Id had saved a lot of money if I had have sat back and tested everything to make sure all was good before embarking on the ECU. As it stands Im really glad I went with the ECU as I hope it will really improve the cars response and also power etc but its always expensive this learning.....
Best of luck and keep us posted.
Cheers
M
Last edited by Macca; 07-14-2011 at 12:07 AM.