Alex Posted July 5, 2005 Share Posted July 5, 2005 The graphs I've got say a similar story Can some one ask JohnA where he got the numbers from? I'd really like to see the dyno sheet as I'm slightly confused by some of the numbers it's showing. I'm on his ignore list so if someone could just quote this in a new post he'll see my request. Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 5, 2005 Share Posted July 5, 2005 Can some one ask JohnA where he got the numbers from? I'd really like to see the dyno sheet as I'm slightly confused by some of the numbers it's showing. I'm on his ignore list so if someone could just quote this in a new post he'll see my request. Alex you those are Excel charts not dyno sheets I've got the power and torque curves from the same dyno run that the boost curves came from, I'll post them up when I get home tonight. They don't look much like those Excel charts though - 350ftlb at 2000rpm?! I wish -Ian Quote Link to comment Share on other sites More sharing options...
Wez Posted July 5, 2005 Share Posted July 5, 2005 You can see the boost pressure curve of both modes of operation. Sequential absolutely kicks the arse of parallel up to about 3350rpm. Then, parallel gets up to 1 bar by 3500rpm, therefore being better for 150rpm. After that, and this is the traction-breaking moment that makes parallel mode *seem* more powerful, there is a really nasty boost spike to 1.3bar - scary when the boost pressure is supposed to be 1.0bar. This lasts for 400rpm before the wastegate opens - the wastegate isn't used until about 3900rpm because the stock ECU doesn't need it to control boost until then - as far as it's concerned, the EGBV controls boost until then. As you can see, by 4000rpm the wastegate has dragged things back under control and the boost pressure, and therefore power, is exactly the same as sequential mode No higher boost, no magic increase in performance, nothing. -Ian Hello Ian, Maybe you can confirm this for me but I get the impression that when most people install boost controllers, regardless if its manual or electronic they seemt to plumb them in parrallel/series to the stock ECU boost control. Would it not be far easier if switching to true twin (not that i would have) that you completly bypass the ECU control and use a seperate controller. Is there any need for the stock ecu to still have any control over whats happening turbo wise if you have another boost control method setup correctly? Quote Link to comment Share on other sites More sharing options...
MONKEYmark Posted July 5, 2005 Share Posted July 5, 2005 would you get a better 1/4 mile time in Paralell as the rpm will always be above 4,000 (apart from 1st gear unless you managed a good start) i.e. taking advantage of the higher boost compared to seq above 4,000 rpm. anyone tried both down the drag strip on the same day ? i once tried on stock tc 13.7 on ttc 13.2 on seq on stock stall in ttc is like you put your foot down and wait and wait then whhhooooaaaaaa its off like a rocket. you cant really launch any harder as tyres just start spinning on spot. in seq you just seem to get off line better. Quote Link to comment Share on other sites More sharing options...
JohnA Posted July 5, 2005 Share Posted July 5, 2005 If you manage to keep it above 4Krpm in both cases, I don't see any reason for any of the two setups to have an edge. Airflow will be the same, so will fuelling and ignition. But if you use the rev range below 4K, then the sequential will start having an advantage, with more torque available and the ECU having more optimised curves for it. Quote Link to comment Share on other sites More sharing options...
Jake Posted July 5, 2005 Share Posted July 5, 2005 If you manage to keep it above 4Krpm in both cases, I don't see any reason for any of the two setups to have an edge.but you can't pull away at 4000RPM because the stock torque converter restricts power braking to a max of 2000rpm Quote Link to comment Share on other sites More sharing options...
JohnA Posted July 5, 2005 Share Posted July 5, 2005 exactly. Plus the original question was from someone with a manual, wasn't it? Quote Link to comment Share on other sites More sharing options...
Jake Posted July 5, 2005 Share Posted July 5, 2005 It was indeed but MonkeyMark's post was about an Auto. I thought I was replying to your reply to Mark. (IYSWIM) No probs. Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 5, 2005 Share Posted July 5, 2005 Hello Ian, Maybe you can confirm this for me but I get the impression that when most people install boost controllers, regardless if its manual or electronic they seemt to plumb them in parrallel/series to the stock ECU boost control. Would it not be far easier if switching to true twin (not that i would have) that you completly bypass the ECU control and use a seperate controller. Is there any need for the stock ecu to still have any control over whats happening turbo wise if you have another boost control method setup correctly? Aha, I see what you are saying, yes - OK, you can possibly remove the boost spike with some careful tweaking of your boost controller and bypassing the stock VSV So you'll get about 500rpm of better performance rather than 150rpm The bottom end will still be just as bad though. -Ian Quote Link to comment Share on other sites More sharing options...
Suprasteve Posted July 5, 2005 Share Posted July 5, 2005 my conclusion... so unless you've got a highly modded car and need remapping or just want better fuel consumption there is no real other advantage for changing from standard seq set up to true twin turbo set up. Also unless you've fitted a boost controller in a special way the ttc set up could potentially cause boost spiking of around 1.3 bar which is a serious no no with stock turbos. looks like i'm sticking to seq for the mo. please correct me if i'm wrong. thanks for all the knowledge, you knowledgeable people BTW, yes i have a manual. Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted July 5, 2005 Share Posted July 5, 2005 John, what is the deal with those dyno charts Alex posted, I *think* they are Excel sheets too??? What type of rollers were they from?? Quote Link to comment Share on other sites More sharing options...
JohnA Posted July 5, 2005 Share Posted July 5, 2005 John, what is the deal with those dyno charts Alex posted, I *think* they are Excel sheets too??? What type of rollers were they from?? Yeah, they look like Excel to me too. They came from the same old Autospeed article. I could email it to you if you like, but it isn't a technical diatribe, more like a journalistic description. Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted July 5, 2005 Share Posted July 5, 2005 No I will look throught autospeed as I have a memebership if you have the link? Quote Link to comment Share on other sites More sharing options...
JohnA Posted July 5, 2005 Share Posted July 5, 2005 no link, because these I had downloaded as units years ago. It was called "engine ecstasy VVTi Supra Turbo" Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted July 5, 2005 Share Posted July 5, 2005 if it was a white car I think I remember it Quote Link to comment Share on other sites More sharing options...
JohnA Posted July 5, 2005 Share Posted July 5, 2005 I've got it on my webspace along with their other supra articles at the time, if you can't find it I could PM you the link Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 7, 2005 Share Posted July 7, 2005 Finally remembered to hoik these dyno charts out. The left hand one is torque, the right hand one is horsepower. It's easy enough to spot which are the sequential and which are the parallel curves - the parallel curves are the ones that sit low then spike just before 4krpm. As far as I recall this car was boosting to 1bar so was mildly tweaked, fairly close to stock. The power figures reflect this. Note the values on this dyno sheet don't match the Excel chart posted earlier, torque at 2000rpm is 120ftlbs in Seq (certainly not 350!) and a piss-poor 60ftlbs in Par (definitely not 220!). Power figures are similarly disparate. Christ knows what the data behind those charts are from Anyone still interested in parallel mode? -Ian Quote Link to comment Share on other sites More sharing options...
eyefi Posted July 7, 2005 Share Posted July 7, 2005 Anyone still interested in parallel mode? i have a completely different experience of parallel. on that same dyno i made just under 400hp/tq with no boost spikes whatsover (blitz dsbc). the car had great afr's (powerfc) through the run and in general. i lost some area under the curve at low rpm, which i cared not about and gained some in the mid range, which i did like. i got a much friendlier curve, without that aweful dip and the risk of 2nd turbo interuption mid corner. parallel does not make more peak power, it does make a stronger mid range. i think the whole thing is totally subjective and the example you have chosen to compare is about the worst example ever the first time i tried parallel i thought it was dreadful, it didn't take long for sequential to feel weird. i love parallel and i had it working great, so there! Quote Link to comment Share on other sites More sharing options...
JohnA Posted July 7, 2005 Share Posted July 7, 2005 could it be that your sequential was defective, with the valves not opening correctly? Had you changed the rubber hoses with silicon ones? Quote Link to comment Share on other sites More sharing options...
Nic Posted July 7, 2005 Share Posted July 7, 2005 I totally agree with you eyefi. Ian, the comparative dyno results you posted, was this the same car, ie dyno'd in sequential and then parallel? Was the car mapped differently for sequential and parallel setup? The e-manage on my car was specifically mapped for parallel operation, I don't get any boost spikes, just smooth, strong power delivery through the rev range. Quote Link to comment Share on other sites More sharing options...
eyefi Posted July 7, 2005 Share Posted July 7, 2005 could it be that your sequential was defective, with the valves not opening correctly? Had you changed the rubber hoses with silicon ones? no, it was functioning perfectly no, rubber hoses. Quote Link to comment Share on other sites More sharing options...
JohnA Posted July 7, 2005 Share Posted July 7, 2005 I understand that direct comparisons between parallel and sequential will probably tend to favour the sequential, as the ECU fuelling and ignition curves will be better matched for that. It would be interesting to see comparisons on the same car, with both setups optimised. Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 7, 2005 Share Posted July 7, 2005 I totally agree with you eyefi. Ian, the comparative dyno results you posted, was this the same car, ie dyno'd in sequential and then parallel? Was the car mapped differently for sequential and parallel setup? The e-manage on my car was specifically mapped for parallel operation, I don't get any boost spikes, just smooth, strong power delivery through the rev range. Same car back to back mate. You can't compare yours to one that has simply had the actuators wired open. I consider this dyno chart an accurate representation of the 'average' parallel mod on a j-spec car, without a boost controller installed in a cerain way or some serious ecu remap -Ian Quote Link to comment Share on other sites More sharing options...
Guest supraman582 Posted May 12, 2009 Share Posted May 12, 2009 I had the same feelings my mechanic decided to switch them to true twin and the car sounded awful until the turbos kicked in, and i actually lost 2 seconds down the strip due to this. Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted May 12, 2009 Share Posted May 12, 2009 Typical, you wait 4 years for affirmation....and then Quote Link to comment Share on other sites More sharing options...
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