Guest Carls Veilside Posted August 17, 2003 Share Posted August 17, 2003 Hi all, im new to the forum. (And Yeh, ive searched on this subject and nothing found) Just got myself a UK Auto 1995reg The car already has a Blitz Nur Spec Cat Back system but im looking to take out the second cat. Firstly though I want to put in a couple of gauges. So i was wondering, seeing as we have two turbo’s, is there any way of having a separate boost gauge for each turbo (can u get separate pressure readings from each turbo???) Has anyone done this or knows if it’s possible?? Any info would be much appreciated Thanks Carl Quote Link to comment Share on other sites More sharing options...
mawby Posted August 17, 2003 Share Posted August 17, 2003 It's not possible, not with any meaning to the readings anyway. If you look at this diagram you'll see the output from both turbo's join the same pipe that goes to the CAC. I believe the guage needs to be reading from after the throttle vavlue to get an accurate reading, otherwise you'd be reading the boost up against this value rather than the boost making it into the engine. Can someone more knowledgable confirm this? Quote Link to comment Share on other sites More sharing options...
Steve W Posted August 17, 2003 Share Posted August 17, 2003 I think that sounds fair Mawb's.... PLUS, it would confuse the hell out of ME ! ! (just as No. 2 comes in, wouldn't No.1 drop and PROBABLY No.2 would go UP, down a tad, then UP again... ? ? I don't REALLY have time to watch the ONE guage long enough You want Boost 'to' the Inlet manifold, jjsut as Mawb says.... GOOD, SENSIBLE question though ! ! ! Quote Link to comment Share on other sites More sharing options...
Guest Carls Veilside Posted August 17, 2003 Share Posted August 17, 2003 Cheers for the replys guys, its baffled me too! Just thought it might be interesting to have seperate boost readings incase one of the turbos wasnt performing as it should, (would be very trick looking also!) If anyone else has any comments on the subject i would appriciate there input. Thanks Carl Quote Link to comment Share on other sites More sharing options...
Supragal Posted August 17, 2003 Share Posted August 17, 2003 Hey, I was researching this too as I want 2 boost gauges... I was recommended a jap tuning place to speak to (don't ask me the name it was ages ago!) so I called them and asked them the question. The conversation went something like this: Me: Is it possible to have a boost gauge for each turbo? Bloke: Is it a manual or auto? Me: Manual Bloke: Yes you can then Me: So you can't on an auto? Bloke: No So I'd taken it for red that you could on a manual (I know Carls is an auto) but what's the difference?!!? Probably shoulda asked him that with hindsight.... Would love to have 2- someone out there must have 2 or at least have tried? SG Quote Link to comment Share on other sites More sharing options...
Steve W Posted August 17, 2003 Share Posted August 17, 2003 AFAIK the turbo/sequential set-up is the same on the auto and manual ? ! Don't know what difference it makes ? Quote Link to comment Share on other sites More sharing options...
Supragal Posted August 17, 2003 Share Posted August 17, 2003 Well thats what I figured too, but I suppose on reflection he told me what I wanted to hear so I didn't dispute it. Shoulda done really. I'm gonna be gutted if I can't have 2. Boooooo. Quote Link to comment Share on other sites More sharing options...
Steve W Posted August 17, 2003 Share Posted August 17, 2003 You can always have TWO.... but link 'em both to the same oulet... LOOK good, but same reading.... derrrrrrrrrrrrr...... Quote Link to comment Share on other sites More sharing options...
Supragal Posted August 17, 2003 Share Posted August 17, 2003 Whats the point in that? Quote Link to comment Share on other sites More sharing options...
Steve W Posted August 17, 2003 Share Posted August 17, 2003 NONE whatsoever ! ! BUT, if you want TWO no matter what................... ******************************************** sorry, being Sunday-Night-Silly....haven't had me tea yet... I'll stop rabbiting.............................................. ******************************************** I suppose it might be 'slightly' useful to have the MAIN one on the Inlet and one on No.2 outlet ? but the No. 2 one would still be fluctuating up and down like a YO-YO 'cos of the sequential gubbins..... The MAIN one on the INLET manifold is the MUST guage though that's the ACTUAL boost to the engine, that's the figure you REALLY need. (that one told me exactly WHY I blew mine up ! 1.4/1.5Bar = BOOM) Quote Link to comment Share on other sites More sharing options...
Supragal Posted August 17, 2003 Share Posted August 17, 2003 I didn't mean no matter what, I meant that I wanted to have a reading for each turbo. Wanted "turbo 1" and "turbo 2" written on the gauges Bit of a waste of money having 2 reading hte same thing or inaccurate. But one at least is essential- as you proved lol Quote Link to comment Share on other sites More sharing options...
Ian C Posted August 18, 2003 Share Posted August 18, 2003 The gearbox makes no difference to the operation of the sequential systems so whoever told you that was, shall we say, misinformed. The outputs from both turbos are linked, as has been mentioned, turbo 2 has a butterfly flap stopping turbo 1 from backspinning it when 2 isn't online, so the only place to mount a second boost gauge would be between turbo 2 and this flap (the Intake Air Control Valve) but that would be pointless as it would read zero, and when the flap opened, it would read the combined boost, i.e. the same as the other gauge Steve is right in saying you want to know the intake manifold pressure, i.e. what's entering the engine. However, you could easily connect an LED to the output from the ECU which controls the IACV so that it lit up when #2 came online... Not just blingtastic, it could help diagnosing those tricky sequential ops bugs that crop up now and again. If anyone can contribute with the electronics side of attaching LEDs to ECU outputs I'd be grateful - I'm under no impression it's a straight wire-to-LED affair, I'm sure there are resistors in there somewhere -Ian Quote Link to comment Share on other sites More sharing options...
400BHP Posted August 18, 2003 Share Posted August 18, 2003 I can supply you with the wiring diagram, but then you'll have to trace it. And boost gauges do normally go after the throttle butterfly, because if you notice it should have a vacuum reading on it in mm/hg (millimeters of mercury) to show what vacuum you have in the manifold when throttle is closed. Quote Link to comment Share on other sites More sharing options...
Guest Carls Veilside Posted August 18, 2003 Share Posted August 18, 2003 I think i just better go with one boost gauge and an oil pressure gauge. its all toooooo confusing for me Oil Pressure??? Everyone agree??? Quote Link to comment Share on other sites More sharing options...
Alex Posted August 18, 2003 Share Posted August 18, 2003 If you want to fit 2 gauges make them 1x boost and 1x EGT (Exhaust Gas Temp) Quote Link to comment Share on other sites More sharing options...
400BHP Posted August 18, 2003 Share Posted August 18, 2003 Oil Press, Fuel Press, Oil temp, Diff temp, Transmission Temp, Exhaust Gas Temp, Amps, Volts, Boost..... Quote Link to comment Share on other sites More sharing options...
Supragal Posted August 18, 2003 Share Posted August 18, 2003 I just wanted 2 boost gauges coz it's more scary for passengers and also for trouble shooting... *sigh* deeply upset. The LED light sounds pretty cool though Am looking at getting all those gauges- anyone know a make that does them all? (They all seem to do a selection and I want them to match....) Quote Link to comment Share on other sites More sharing options...
Ian C Posted August 18, 2003 Share Posted August 18, 2003 Actually I'm thinking more about the LEDs as you could have four, and it would be great to see exactly when all the gubbins does what it does. And of course it would look great if you labelled them up properly or something so you could see it light up "Prespool" then "Exhaust" shortly followed by "Intake" (surge of power) then "Wastegate". Groovy. Question is, what colour should the LEDs be? And how should they be displayed?! And is it far too blinging for me to be considering it? I know the wiring, I just recall from years ago that LEDs need a resistor inline with them or something and I really can't be arsed to look up that basic bit of electronics Someone must know off the top of their head... -Ian Quote Link to comment Share on other sites More sharing options...
Supragal Posted August 18, 2003 Share Posted August 18, 2003 Great minds think alike- labeling is definately the way forward. Perhaps a red led for the "boost" part of it with staged leds leading up to it... hee hee. Leccy stuff is beyond me so if anyone knows..... Quote Link to comment Share on other sites More sharing options...
Digsy Posted August 18, 2003 Share Posted August 18, 2003 You mean the "current limiting resistor", which is put in series with the LED: R = (Vs - Vf) / If or: R = (Supply Voltage - Forward Voltage) / Forward Current Vf and If are characteristics of the LED. Supply voltage is whatever you are trying whack through it - probably 12V in our case. Probably better to put something between the LED and the ECU though... Quote Link to comment Share on other sites More sharing options...
Ian C Posted August 18, 2003 Share Posted August 18, 2003 Originally posted by Supragal Great minds think alike- labeling is definately the way forward. Perhaps a red led for the "boost" part of it with staged leds leading up to it... hee hee. Leccy stuff is beyond me so if anyone knows..... Well, I don't mind getting my hands dirty with the leccy side of things, but I can't design anything that looks good - I'm a bit "function over form". I'll trade you - you get busy photoshopping designs and I'll get researching "how to fit LEDs without blowing up the ECU" -Ian Quote Link to comment Share on other sites More sharing options...
Ian C Posted August 18, 2003 Share Posted August 18, 2003 Originally posted by Darren Blake You mean the "current limiting resistor", which is put in series with the LED: R = (Vs - Vf) / If or: R = (Supply Voltage - Forward Voltage) / Forward Current Vf and If are characteristics of the LED. Supply voltage is whatever you are trying whack through it - probably 12V in our case. I was about to PM you, Mr. Blake, but you've stepped into the fray admirably. Shame I haven't got a clue what you just said How about if I find a pwetty coloured LED and give you the stats, you tell me the resistor I need? Probably better to put something between the LED and the ECU though... An impenetrable steel cage to stop me messing about with it...? But seriously, what do you mean by this? -Ian Quote Link to comment Share on other sites More sharing options...
Digsy Posted August 18, 2003 Share Posted August 18, 2003 Well, I was thinking if you are going to take signals straight out if the ECU you might want to put something between the ECU and the LED - sort of like a relay - so that the LED circuit and the ECU gubbins remain seperated. However, just thinking about it a bit more, if you took the signal from the "valve end" (probably a higher current) then I reckon you could tap off about 20mA to drive the LED without messing anything up. Only thing is, IIRC the Supra has all its switches on the earth side of the circuit, so it may take some head scratching to hook the LED into the loom. Possibly a question for Mr. Betts. Quote Link to comment Share on other sites More sharing options...
Ian C Posted August 18, 2003 Share Posted August 18, 2003 Dredging up what I know of electronics, you mean something like an opto-isolator? We are getting into the realms of small circuits with those dodgy black chippy things on, right? That makes sense if it's to be done properly. As for earth-based switching, I'll have to examine the ECU circuit diagram I've got at home to see exactly what's what... -Ian Quote Link to comment Share on other sites More sharing options...
Digsy Posted August 18, 2003 Share Posted August 18, 2003 I was going to say "like an opto-isolator" but decided it sounded too geeky but yes. Or possibly even a transistor of some sort. Pete Betts is your guy for that side of things I reckon. Earth-switching: I just remember from my mega foglamp conversion that everything seemed to have a fixed 12V feed with the switch on the half of the circuit that goes to 0V (i.e. between the component and the earth point) which is the opposite way around to what I expected. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.