nurrish Posted September 13, 2009 Share Posted September 13, 2009 Having had a dyno yesterday at Surrey Rolling road i need some analysis as i have no idea what to make of my results......... So this is my first run back in june when i was totally untuned Then having visited RSTuning and got a remapped Then yesterday at the surrey rolling road After speaking with the chap that did the dyno yesterday he said that there was nothing wrong with my rstuning dyno. What i dont get is that yesterday he done the run in 3rd gear where as my other runs where done in 4th...... I'm not overly bothered but just wondering if there are any experts would like to shed some light on what they make of my 3 runs Quote Link to comment Share on other sites More sharing options...
rtbiscuit Posted September 13, 2009 Share Posted September 13, 2009 yesterdays was a smoother run looking at the dyno sheet, but its difficult to compare, every dyno is different, and each day is different having an effect on the result. your best bet is to start and then stick to one dyno for camparisons, as it will show the changes better. Quote Link to comment Share on other sites More sharing options...
BulletMagnet Posted September 13, 2009 Share Posted September 13, 2009 I'd say that the RSTuning chart is not calibrated properly. The stock figure is rated at 287HP, and the post-reflash at 301HP. Take off 24HP off both values, then it would make more sense, as the base line would be near what Weston Performance and Surrey Rolling Road measured. But then it wouldn't explain how the gain at RSTuning was lost inbetween both dyno sessions. Quote Link to comment Share on other sites More sharing options...
nurrish Posted September 13, 2009 Author Share Posted September 13, 2009 I'd say that the RSTuning chart is not calibrated properly.The stock figure is rated at 287HP, and the post-reflash at 301HP. Take off 24HP off both values, then it would make more sense, as the base line would be near what Weston Performance and Surrey Rolling Road measured. But then it wouldn't explain how the gain at RSTuning was lost inbetween both dyno sessions. Well to be honest i always thought that the rstuning reading was a tad high from the first run. But if i take my first reading which is 263 and then my recent reading 282 i have a gain of 19bhp. I just find it odd that yesterday my run was done in 3rd yet the other 2 dyno's were done in 4th which makes analysing it more difficult. Quote Link to comment Share on other sites More sharing options...
BulletMagnet Posted September 13, 2009 Share Posted September 13, 2009 We really need to know whether the gear used actually makes a difference in the result. Best have RSTuning and/or Abbey Motorsport comment on this. Quote Link to comment Share on other sites More sharing options...
Ekona Posted September 13, 2009 Share Posted September 13, 2009 It does make a difference, yes. Not a huge one, but in lower gears you can get more slipping from the tyres amongst other issues, hence most dyno runs are done in 4th gear. Tbh as Rich said a dyno is only worthwhile as a comparison on one particular day as weather conditions alter readings a lot, and comparing between dynos is pointless. If the car feels right, and the graphs look okay then it's better just to ignore the numbers up to a point. Quote Link to comment Share on other sites More sharing options...
3FIDDYZ Posted September 13, 2009 Share Posted September 13, 2009 FYI on the dyno's about 8 weeks ago mine was in for tuning at GTart, it got to 287, the day after it ran 291 at SRR, then ran mine yesterday at SRR it got 291.. so its reading right if not a little high at SRR.. The part about the dyno reading different on different days no longer really hold for david anymore as its been reflashed so it shouldnt be changing (clarification needed from Abbey or RS on that one...) But I would say that potentially a 20bhp loss needs looking at as to me, after all you have paid for an increase! If you look at your torque numbers (perhaps more important!) you have the same on your first and last but your RS one is way more... Also look where your torque / bhp numbers are starting at RS... 2250 revs, where as the other numbers start lower... Quote Link to comment Share on other sites More sharing options...
nurrish Posted September 13, 2009 Author Share Posted September 13, 2009 FYI on the dyno's about 8 weeks ago mine was in for tuning at GTart, it got to 287, the day after it ran 291 at SRR, then ran mine yesterday at SRR it got 291.. so its reading right if not a little high at SRR.. The part about the dyno reading different on different days no longer really hold for david anymore as its been reflashed so it shouldnt be changing (clarification needed from Abbey or RS on that one...) But I would say that potentially a 20bhp loss needs looking at as to me, after all you have paid for an increase! If you look at your torque numbers (perhaps more important!) you have the same on your first and last but your RS one is way more... Also look where your torque / bhp numbers are starting at RS... 2250 revs, where as the other numbers start lower... Thanks for your input mark much appreciated I have contacted rstuning so we shall see what they have to say Quote Link to comment Share on other sites More sharing options...
Darren-B Posted September 13, 2009 Share Posted September 13, 2009 personally for the unreliable gains you guys potentially have made from rs tunning I would like to see a few others with consistant results before i would consider going there for a re-map. Quote Link to comment Share on other sites More sharing options...
RSTuning Posted September 13, 2009 Share Posted September 13, 2009 There is nothing unreliable about any gains we made with the mapping at all on any of the cars. People are too hung up on the actual numbers from Dyno to Dyno when this is near impossible to compare due to different operators. I took the decision to run the Z like I do. On a factory stock 276 hp one it will be about on The money. If people would rather I tighten the limit straps so the car can't move in the rollers then I can and this could change the numbers by 20 hp or so on a 300hp 2wd vehicle. The idea of a before and after is to show actual gains. This allows you to see how much and where. Quote Link to comment Share on other sites More sharing options...
IanS16 Posted September 13, 2009 Share Posted September 13, 2009 I would have thought the only real way of knowing would be to go back to Westons and get it done there again as they have nothing to gain by boosting numbers and you got it done there before the remap. Quote Link to comment Share on other sites More sharing options...
3FIDDYZ Posted September 13, 2009 Share Posted September 13, 2009 SRR are indepentent testers so nothing for them to gain either Ian. But I think your right... Just to clarify RS, you keep the straps loose so it gives better numbers? Or you tighten them up and it gives you 20 more? I dont think its the case of being hung up on the numbers, how else are we supposed to tell!! Unfortunatly there is a magic 300bhp number with these cars (yep psycological!)! Also on the increases between different dynos I understand the logic, the car made 14bhp on your rollers but between the weston and the SRR it made 19.2 so there is a bit of room for differnet rollers. On the torque however, between the weston and SRR 0 increase... but on RS's it found 30ft/lbs or so.. Given the different rollers and a rough % calculation I would have thought you would have been showing about 275 ft/lbs on the SRR? Quote Link to comment Share on other sites More sharing options...
Ekona Posted September 14, 2009 Share Posted September 14, 2009 The idea of a before and after is to show actual gains. This allows you to see how much and where. This, a million times this. Guys, you cannot compare data between dynos done in different places on different days by different operators as there's too many variables. It's irrelevant if the RST dyno over reads or not, as it will still give you the true bump in power between the first run done before the map and the run done after. Quote Link to comment Share on other sites More sharing options...
BulletMagnet Posted September 14, 2009 Share Posted September 14, 2009 The idea of a before and after is to show actual gains. This allows you to see how much and where. This, a million times this. Guys, you cannot compare data between dynos done in different places on different days by different operators as there's too many variables. It's irrelevant if the RST dyno over reads or not, as it will still give you the true bump in power between the first run done before the map and the run done after. While this is true Dan, it is confusing to me (and probably Dave too) why the run at SRR is back down to near stock figures, after it had the initial stock run and remap run at RSTuning. I'm not saying that RSTuning are no good, but maybe more explaining for us newbies would help for clarification sake. Quote Link to comment Share on other sites More sharing options...
RSTuning Posted September 14, 2009 Share Posted September 14, 2009 SRR are indepentent testers so nothing for them to gain either Ian. But I think your right... Just to clarify RS, you keep the straps loose so it gives better numbers? Or you tighten them up and it gives you 20 more? I dont think its the case of being hung up on the numbers, how else are we supposed to tell!! Unfortunatly there is a magic 300bhp number with these cars (yep psycological!)! Also on the increases between different dynos I understand the logic, the car made 14bhp on your rollers but between the weston and the SRR it made 19.2 so there is a bit of room for differnet rollers. On the torque however, between the weston and SRR 0 increase... but on RS's it found 30ft/lbs or so.. Given the different rollers and a rough % calculation I would have thought you would have been showing about 275 ft/lbs on the SRR? As each operator is different we probably all strap the cars slightly different, personally i use 2 main straps and 2 limit straps, the limit straps control how much the car can move forward onto the front roller. IF the limit straps are pulled too tight and the car can't climb the numbers are lower. I do it this way as i find it VERY consistent and easy to control. Maybe i'm wrong but maybe SRR are wrong. There is only one way to test and i'm sure this wont happen. For an accurate FLY resut you must take the engine out and run on an engine dyno. I use our dyno as a tuning tool, not as a tool to advertise the numbers and for most the figures are lower than any other RR in the UK. Quote Link to comment Share on other sites More sharing options...
RSTuning Posted September 14, 2009 Share Posted September 14, 2009 The idea of a before and after is to show actual gains. This allows you to see how much and where. This, a million times this. Guys, you cannot compare data between dynos done in different places on different days by different operators as there's too many variables. It's irrelevant if the RST dyno over reads or not, as it will still give you the true bump in power between the first run done before the map and the run done after. While this is true Dan, it is confusing to me (and probably Dave too) why the run at SRR is back down to near stock figures, after it had the initial stock run and remap run at RSTuning. I'm not saying that RSTuning are no good, but maybe more explaining for us newbies would help for clarification sake. Assuming that SRR and Weston did not allow the car to climb the rollers the difference between the two will be the HP gains, you can't compare the torque unless the ignition tacho was used as this directly affects the displayed torque reading. If he wants to run again i will but as said comparing dyno to dyno is not reliable unless everything is done exactly the same. Quote Link to comment Share on other sites More sharing options...
Adriank Posted September 14, 2009 Share Posted September 14, 2009 I think one of the things that interested people was the quite large variation in power outputs on the dyno... We were all there on the same day so the results between cars should be comperable. Is there a particular factor on the 350Z that could be limiting nurrish's numbers? He said the car was mapped with his bungs in the exhaust, which creates a fairly large restriction... Just as comparison we had cars outputting 265-291 bhpon these rollers, in different states of tune, but not necessarily in the order you might think Quote Link to comment Share on other sites More sharing options...
3FIDDYZ Posted September 14, 2009 Share Posted September 14, 2009 I think one of the things that interested people was the quite large variation in power outputs on the dyno... We were all there on the same day so the results between cars should be comperable. Is there a particular factor on the 350Z that could be limiting nurrish's numbers? He said the car was mapped with his bungs in the exhaust, which creates a fairly large restriction... Just as comparison we had cars outputting 265-291 bhpon these rollers, in different states of tune, but not necessarily in the order you might think Always been the case on the different power with Zeds Ady, some are good some not so.. Interested on the bungs too, as Chris said, every car he has dyno'd before they have given more power when removing... Does this mean that the reflash is still adjusting now? RS, on the strap thing, have now dynoed in 3 places now with different variables and had consistant numbers, all have been strapped pretty tight from what I can tell so am happy that mine is now a lower "figure" than what it would be more loosly strapped that would give me a higher one. **EDIT** Apologies, I have just been informed that ours were done "loose".... Quote Link to comment Share on other sites More sharing options...
dcash5 Posted September 14, 2009 Share Posted September 14, 2009 Adi you say the cars had some amounts of difference but one thing for certain is ... all the cars with High Flow Cats all produced 290bhp ish. Definately a very interesting point! Quote Link to comment Share on other sites More sharing options...
RSTuning Posted September 14, 2009 Share Posted September 14, 2009 I think one of the things that interested people was the quite large variation in power outputs on the dyno... We were all there on the same day so the results between cars should be comperable. Is there a particular factor on the 350Z that could be limiting nurrish's numbers? He said the car was mapped with his bungs in the exhaust, which creates a fairly large restriction... Just as comparison we had cars outputting 265-291 bhpon these rollers, in different states of tune, but not necessarily in the order you might think If the cars were all run the same then you should be able to compare really yes. The only issue with the older DD is the weather station is not automatic and the user needs to input the info all day to keep things accurate. Like i said above, a stock 276 car will make 276hp give or take. The main point is that to compare dyno to dyno is not really possible and thats the reason we offer the before and after to show the actual gains. If Abbey map a car the numbers from their hub dyno will be different again... Quote Link to comment Share on other sites More sharing options...
Mark@Abbey m/s Posted September 14, 2009 Share Posted September 14, 2009 Comparing dyno,s will always open a can of worms, even more when you start adding run down BHP to wheel figures to get a "flywheel" figure. Running in different gears will provide a slightly different BHP figure due to the loss in a higher numeric ratio while running in 3rd. Running longe ror shorter runs can give different figures so many variables. Also running the cars loose as in not tied down will give different figures. As the RS tuning man (sorry dont know your name) our figures will be different again as we read at the hubs. Dyno days always end of with people asking questions, before and after on the same dyno under the same conditions is the only way to get a good reading. Quote Link to comment Share on other sites More sharing options...
3FIDDYZ Posted September 14, 2009 Share Posted September 14, 2009 Comparing dyno,s will always open a can of worms, even more when you start adding run down BHP to wheel figures to get a "flywheel" figure. Running in different gears will provide a slightly different BHP figure due to the loss in a higher numeric ratio while running in 3rd. Running longe ror shorter runs can give different figures so many variables. Also running the cars loose as in not tied down will give different figures. As the RS tuning man (sorry dont know your name) our figures will be different again as we read at the hubs. Dyno days always end of with people asking questions, before and after on the same dyno under the same conditions is the only way to get a good reading. Didnt realise you had a hub dyno Mark, may have to pop by for a comparison Quote Link to comment Share on other sites More sharing options...
Bundus Posted September 14, 2009 Share Posted September 14, 2009 I think the best thing to do is find a dyno place that you like and make sure you always take it there after changing things or adding mods. As has been said if the car is run on one dyno, then mods made, then run on the same dyno under same conditions then the difference in figures will be your change. Regardless of whether the start figure was higher or lower then what you have seen at other dynos. Nurrish if you take yours to RS tuning for another run and they run it exactly as they did before then you should see the same numbers again. This wont explain why other dynos are different but it will put your mind at rest that the car hasnt dropped a load of power since you had it tuned. Quote Link to comment Share on other sites More sharing options...
nurrish Posted September 14, 2009 Author Share Posted September 14, 2009 Thank you all for the input. I really do appreciate that ever dyno is going to get different results and i am almost certain that if i were to return to rstuning i will see the same figure which i got when tuned. I'm sure you'll understand the disheartening feeling seeing my car hit what it did on ssr espically after seeing an untuned adriank hit 290 without any tune.... But like people have said its best to stick to 1 dyno and gauge the gains from the one setup Quote Link to comment Share on other sites More sharing options...
Bundus Posted September 14, 2009 Share Posted September 14, 2009 I know how you feel mate - it must be gutting to see such a difference. Its upsetting to think that we could spend thousands on our cars only to have them come in less then a standard one purely because the standard one was so much more powerful out of the factory. Is there some comeback we have as a buyer if we buy a car and its power at the dyno is less then the stated power? Ive never looked at it like this before but if your buying a new car and they vary on power so much it would make sense to test drive a few and dyno them. Why pay thousands of pounds tuning a car for an extra 20 bhp when 3 different ones from the factory may already be 20bhp apart. Get the most powerful one from the factory and youve saved a fair penny on tuning. I was just thinking I wonder what AdrianK's would come in at over at RS? Quote Link to comment Share on other sites More sharing options...
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