teneille666nz Posted July 23, 2015 Share Posted July 23, 2015 Hi all just had my car tuned today and gone from 200hp(run in tune) to 187hp just like that. Im a bit gutted. Running a forged engine on 95octane with 74.5 bore, gt20 turbo on about 24psi, 500cc injectors and a haltec ecu and along with other supporting mods. I honeslty expected a bit more out of my little rocket. Just askin for any thoughts to as why this may have happend? Quote Link to post Share on other sites
AdamB Posted July 23, 2015 Share Posted July 23, 2015 When was the first tune done? What was the air temperature like compared to the second dyno run where you made 187bhp? Quote Link to post Share on other sites
teneille666nz Posted July 23, 2015 Author Share Posted July 23, 2015 Not to sure about the air temp mate i could post printouts if that'll help Quote Link to post Share on other sites
jimmymac101 Posted July 23, 2015 Share Posted July 23, 2015 For the more technical people on here the picture would help Quote Link to post Share on other sites
Flaminsam Posted July 23, 2015 Share Posted July 23, 2015 Possible heat soak? Heat is a major killer of power and engines 😕 Quote Link to post Share on other sites
AdamB Posted July 23, 2015 Share Posted July 23, 2015 Not to sure about the air temp mate i could post printouts if that'll help If you can post both the graphs up mate it might point towards something or another. How many miles were on the motor when it first got tuned and made 200bhp? How many miles on it when it was dyno'd at 187bhp? Quote Link to post Share on other sites
patman Posted July 23, 2015 Share Posted July 23, 2015 Can I just ask aswell, I was told by many people always run 97 petrol or 99 on these engines, as 95 isn't good for it, I know this isn't to do with the dyno but just saw he put 95, or am I missing something here? Quote Link to post Share on other sites
Ollieh17 Posted July 23, 2015 Share Posted July 23, 2015 Can I just ask aswell, I was told by many people always run 97 petrol or 99 on these engines, as 95 isn't good for it, I know this isn't to do with the dyno but just saw he put 95, or am I missing something here?If its mapped to 95octane it would be fine and shouldn't make a difference. But if its mapped to a higher octane fuel it may make some sort of difference Quote Link to post Share on other sites
mikey4410 Posted July 23, 2015 Share Posted July 23, 2015 heatsoak as stated above will for sure ruin power figures,the ecu will pull timing and that will reduce power as a consequence so it stays safe and doesnt det. Quote Link to post Share on other sites
patman Posted July 23, 2015 Share Posted July 23, 2015 If its mapped to 95octane it would be fine and shouldn't make a difference. But if its mapped to a higher octane fuel it may make some sort of differenceThanks Ollie mate am with you now Quote Link to post Share on other sites
AdamB Posted July 23, 2015 Share Posted July 23, 2015 (edited) Can I just ask aswell, I was told by many people always run 97 petrol or 99 on these engines, as 95 isn't good for it, I know this isn't to do with the dyno but just saw he put 95, or am I missing something here? Check on the inside of your petrol flap, usually says on a sticker what the minimum RON number to use. I'm sure you can get away with running 95 on these motors in standard trim. Edited July 23, 2015 by AdamB Quote Link to post Share on other sites
_shaun_ Posted July 23, 2015 Share Posted July 23, 2015 did anything change between the 2 maps? was it the same tuner and dyno? and do they have any idea whats caused it? could be numerous things to be honest but the power seems very low for that set up Quote Link to post Share on other sites
Addymk2 Posted July 23, 2015 Share Posted July 23, 2015 Boost leak? Low compression? Heat soak? Atmospheric differences? Different Dyno? Different/shit oil? Stagnant fuel? Leaky wastegate/actuator? Cracked manifold? Leaking gasket? Slipped timing belt? Carpet stuck under the accelerator? Sticking throttle body?Take your pick it could be anything tbh it's just going to take some serious detective work. Quote Link to post Share on other sites
patman Posted July 23, 2015 Share Posted July 23, 2015 Check on the inside of your petrol flap, usually says on a sticker what the minimum RON number to use. I'm sure you can get away with running 95 on these motors in standard trim.Thanks Adam will have to have a look, I have always used 97 since my rebuild, but if 95's fine then so be it Quote Link to post Share on other sites
teneille666nz Posted July 24, 2015 Author Share Posted July 24, 2015 Cheers for the input fullas. im running 95 only because it the best i can get without driving 2hrs to the closest gas station that has 98, if i could i would trust me.Anywho had the same tuner same dyno and all the rest of it he did say he had to change the timing(maybe because of the lower fuel?) but now there is a fair knocking coming from the engine, still drives good though. I have to admit its been bloody cold lately compared to its first run and using Castrol Edge 5W-40Just done a compression test and its 150 on all four not to mention i have a 1.2mm head gasket on there too.First dyno tune was after engine was run in and the second one was after maybe 8000ks i just wanted to up the boost and see what she was going to put out lolFor the life of me i cannot put these bloody photos up!! i am trying please bare with me Quote Link to post Share on other sites
teneille666nz Posted July 24, 2015 Author Share Posted July 24, 2015 (edited) Edited July 24, 2015 by teneille666nz Quote Link to post Share on other sites
teneille666nz Posted July 24, 2015 Author Share Posted July 24, 2015 How does suspected bottom end failure sound? Lol olwell back to the shop boys.ill keep you in formed Quote Link to post Share on other sites
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