Dragonball Posted June 4, 2006 Share Posted June 4, 2006 A small search reveals some interesting stuff from Ash (another victim) over 5 years ago Some phsics supporting the injector sizing and effect if you increase from the 36psi stock.... http://www.mkivsupra.net/vbb/showthread.php?t=614&highlight=stock+fuel+pressure Quote Link to comment Share on other sites More sharing options...
Clarkey Posted June 4, 2006 Share Posted June 4, 2006 That's alot of maths ... interesting stuff from Ash (another victim) over 5 years ago Even more .. Quote Link to comment Share on other sites More sharing options...
Pig Posted June 4, 2006 Share Posted June 4, 2006 Alex, im running a brand new walbro pump so i presume the must be clogged up! Its done over 100 K now. I am going to get an Aeromotive FPR, new injectors (not sure exactly which ones to go for) and blitz colour boost controller. This should help sort it out, what boost will i be able to run up to on 650cc?? I would like to be able to up the boost V.High, so is it worth going for a big set of injectors? Now wondering what the stock internals can handle and the autobox?? And, what benefits i would get from changing the cams?! Quote Link to comment Share on other sites More sharing options...
letmeshowyou Posted June 4, 2006 Share Posted June 4, 2006 have you had the compression test done now Jon? What were the results? Quote Link to comment Share on other sites More sharing options...
Pig Posted June 4, 2006 Share Posted June 4, 2006 Nope, Car is going to pheonix as soon as he can fit me in. Am going to stop using it as its leaking coolant now when i use it Its going away untill its sorted. Quote Link to comment Share on other sites More sharing options...
terribleturner Posted June 4, 2006 Share Posted June 4, 2006 Jon, it's leaking coolant?? Why's this?? Radiator on it's way out?? Quote Link to comment Share on other sites More sharing options...
Pig Posted June 4, 2006 Share Posted June 4, 2006 No Brand new fluidline. I dont know where its coming from. It looks like the back of the engine! Quote Link to comment Share on other sites More sharing options...
Gamer Posted June 4, 2006 Share Posted June 4, 2006 This should help sort it out, what boost will i be able to run up to on 650cc?? I would like to be able to up the boost V.High, so is it worth going for a big set of injectors? Now wondering what the stock internals can handle and the autobox?? And, what benefits i would get from changing the cams?! Your turbo (T61 P : 550-600hp(3600-4000rpm)American figures) will give up the ghost before you max out the 650's so no need to go any higher mate. You are limited to how high you can wack up the boost if you are using Optimax. I would say no higher then 1.5-1.6bar tops. Put in some race gas and you can go higher still... Stock internals can go at anytime, it has more to do with the current condition of the engine then it has with the amount of boost you are running. I would say that if your engine is healthy and you have all the supporting mods in place and it is all set-up properly you should have no problems with your internals. I remember you telling me that you have a high mileage engine though so I would be sensible if I was you. Auto box should be good for up to 500rwhp but again that is dependant on the condition of the gearbox and if it has been properly maintained. You should not hammer it though every chance you get as you will be on borrowed time... Cams will enable you to make better use of the power band. Quote Link to comment Share on other sites More sharing options...
michel lane Posted June 4, 2006 Share Posted June 4, 2006 I think alot of people get carried away with how much boost and HP they make . For all you people out there have you actually been in a properly tuned 500hp car ?? 500hp on a small single is alot of power especially the way it delivers the power . I know the idea of having 650hp -800hp is wonderful , but have you driven something like this , espcially on normal roads ?the power comes in to strong, forget about exiting a roundabout in 3rd gear when the boost comes in , the back end just goes dulali , i know RLTC can play a large part in putting the power down , but whats the point in having all that power when the RLTC is cutting it back ?? would you be better having a 500-550hp which is more controlable ??. Thats my opinon...I know coming from me with a PTE71 GTS that sound like crap , but iam actually changing down to a gt4088 for the summer as i prefer this power delivery then my exsisting turbo. I also have a ITS 74DBB GTS going on for drag racing aswell later in the year. Quote Link to comment Share on other sites More sharing options...
TLicense Posted June 4, 2006 Share Posted June 4, 2006 That's alot of maths ... Even more .. It's actually quite a simple equation. I'll attach a spread sheet that will help all.... I've saved the spread sheet for the values as Clarkey has mentioned them on here, so this shoud relate directly to his set-up. However I don't know what duty cycle he's running. I consider 80% to be the maximum I would like to see (subjective) so if we can find out what duty he is running you would simply put that figure in as a decimal into cell B4 and that should tell you the horsepower he can achieve with his particular injectors at the static pressure he mentioned. Hope that helps mate!injector sizing.xls Quote Link to comment Share on other sites More sharing options...
TLicense Posted June 4, 2006 Share Posted June 4, 2006 Go for a Dyno anywhere! Someone will always say "their figures are bullshit" No win situation! Absolutely. People get so transfixed with absolute figures. My phillosophy is to use a dyno figure as a baseline and then use the same dyno and just concentrate on the relative increase (hopefully ) When people ask me what horsepower my car makes, I only ever say it's about X. (My current about number is 350 ) Quote Link to comment Share on other sites More sharing options...
paul mac Posted June 4, 2006 Share Posted June 4, 2006 Oooh, this took off in the last couple of days. Paul Mac, my dear chap -Ian sorry Ian i thought i was getting tag teamed by you and Mr Wilson, fraid i cant tell you anything as the car is off the road at the mo Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 4, 2006 Share Posted June 4, 2006 I think alot of people get carried away with how much boost and HP they make . For all you people out there have you actually been in a properly tuned 500hp car ?? 500hp on a small single is alot of power especially the way it delivers the power . I know the idea of having 650hp -800hp is wonderful , but have you driven something like this , espcially on normal roads ?the power comes in to strong, forget about exiting a roundabout in 3rd gear when the boost comes in , the back end just goes dulali , i know RLTC can play a large part in putting the power down , but whats the point in having all that power when the RLTC is cutting it back ?? would you be better having a 500-550hp which is more controlable ??. Thats my opinon...I know coming from me with a PTE71 GTS that sound like crap , but iam actually changing down to a gt4088 for the summer as i prefer this power delivery then my exsisting turbo. I also have a ITS 74DBB GTS going on for drag racing aswell later in the year. I have quoted your post, as, IMHO, it's worth reading several times as it is so true, and such good sense. Even on my full race Skyline engine, in build, I am only aiming for a max of 600 BHP, and i too will be using a GT4088R for starters. My car had an alleged 560 HP when I got it, cited by several RR readouts. On a proper engine dyno it really had 410, on race fuel and a lot of boostyet still did a low 11'a on street tyres, for you drag race figure lovers. It now has about 440, but with much better drivability, thanks to decent mapping, and the cams being properly timed in. Don't get carried away with power figures, you need area under the graph, good mapping, and a sensibly selected set of engine parts to give reliabilty. Quote Link to comment Share on other sites More sharing options...
Miguel Posted June 4, 2006 Share Posted June 4, 2006 TBH it's not the 1st time it has been said. There is a long list of people that have been saying 500 in a well set up car is awesome. But it's not very good for when you are in the pub chatting about cars Quote Link to comment Share on other sites More sharing options...
Sharpie Posted June 6, 2006 Share Posted June 6, 2006 No Brand new fluidline. I dont know where its coming from. It looks like the back of the engine! Heater Matrix ? Quote Link to comment Share on other sites More sharing options...
b_have Posted June 6, 2006 Share Posted June 6, 2006 What is a gt4088? How does that compare to a T67dbb? Quote Link to comment Share on other sites More sharing options...
Lucifer Posted June 6, 2006 Share Posted June 6, 2006 http://www.mkivstore.com/index.php?target=pages&page_id=443355888 Scroll down to bottom, there is a calculator there if it helps anyone. Quote Link to comment Share on other sites More sharing options...
MarkR Posted June 17, 2008 Share Posted June 17, 2008 Only if there's an increase in static pressure or you run them at 100% duty A good "rule of thumb" is that 1cc of fuel will make 0.6-0.65BHP (B.S.F.C) on a turbocharged car. Multiply that up to 550 and you get 523bhp, but then you wouldn't want to run your injectors more than say 85% so 85% of 523 is 445BHP. Of course if you increase the static pressure, then effectively you're increasing the size of the injector, but then it's no longer flowing 550cc's is it? I'm not having a dig, but is it just me or does 0.6 * 550 not equal 523? I get 330.... Quote Link to comment Share on other sites More sharing options...
bolarbag Posted June 17, 2008 Share Posted June 17, 2008 Have you checked the date on this thread;) Quote Link to comment Share on other sites More sharing options...
MarkR Posted June 17, 2008 Share Posted June 17, 2008 Yup, but info is info Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted June 17, 2008 Share Posted June 17, 2008 Yup, but info is info The info is right, the numbers don't appear to be... but you'd be using your own numbers anyway wouldn't you? Quote Link to comment Share on other sites More sharing options...
MarkR Posted June 17, 2008 Share Posted June 17, 2008 Yup, looking to go single, probably gt35 or t04z, or something similar (trying to organise a few drives on Sunday at JapShow to make up my mind). Don't need huge horsepower figures, but want something very quick off the line up to 120-130 and after that I'm not that fussed. Looking to spec a fuel system with enough headroom if I change my mind later but don't want to go overboard. Probably buy things in bits and pieces and then assemble all at the same time. I initially was going to go for bigger injectors and max out the standard turbos, but decided against that as I know I'll want more so may as well do it properly. Nic has the GT35 with 680 injectors, so was going to do the calcs with that and see how much room I had. Quote Link to comment Share on other sites More sharing options...
bolarbag Posted June 17, 2008 Share Posted June 17, 2008 Yup, looking to go single, probably gt35 or t04z, or something similar (trying to organise a few drives on Sunday at JapShow to make up my mind). Don't need huge horsepower figures, but want something very quick off the line up to 120-130 and after that I'm not that fussed. Looking to spec a fuel system with enough headroom if I change my mind later but don't want to go overboard. Probably buy things in bits and pieces and then assemble all at the same time. I initially was going to go for bigger injectors and max out the standard turbos, but decided against that as I know I'll want more so may as well do it properly. Nic has the GT35 with 680 injectors, so was going to do the calcs with that and see how much room I had. Today 12:35 683cc with bsfc of .65 and a 20%saftey margin was what I calculated IIRC with an aim of 550bhp on the GT35R at 43.5psi Fuel pressure, I'm going 850's as I intend to go with a bigger Turbo after the GT35R, probably a T67dbb, 850's will be more than enough for 650bhp. Quote Link to comment Share on other sites More sharing options...
MarkR Posted June 17, 2008 Share Posted June 17, 2008 683cc with bsfc of .65 and a 20%saftey margin was what I calculated IIRC with an aim of 550bhp on the GT35R at 43.5psi Fuel pressure, I'm going 850's as I intend to go with a bigger Turbo after the GT35R, probably a T67dbb, 850's will be more than enough for 650bhp. Thanks for that. Just the kind of info I was after.... Quote Link to comment Share on other sites More sharing options...
bolarbag Posted June 17, 2008 Share Posted June 17, 2008 Thanks for that. Just the kind of info I was after.... I will post up my workings tomorrow, I dont want to mis-quote the calcs, but 683 defo sticks in my mind, and I know my other aims Regarding other threads where you are gathering info(and this is the reason I hate people automatically posting 'search') A lot of these guys that have posted in these threads have came through the same questions you are asking, and have now tried and tested methods for tuning, so dont take everything you read as gospel, google it and confirm, they were all learning too at one point, we all still are! The physics never changes though, be sure of that;) Quote Link to comment Share on other sites More sharing options...
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