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Location:
Tuscaloosa,Al USA
Registered:
February 2004
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 1g-gte max boost?????
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Tue, 17 February 2004 23:16
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Hey guys. My name is Jamie Wiseman. I own Venture Racing (www.teamventureracing.com), a tuner shop for imports. We have a AE86 with a 1g-gte in it and are about to install a refurbished T04 single turbo upgrade from a Buick Grand National. I was wondering if any of you would know how much boost that engine can handle safely if the fuel cut is disabled. This engine is extremely rare to us here and your site has helped us greatly when we were installing the engine. Also, do any of you know what size injectors are in this motor,the tops are yellow in colour.
Thanks for any help or suggestions.
Jamie Wiseman
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Location:
Madrid - Spain
Registered:
August 2002
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Re: 1g-gte max boost?????
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Tue, 17 February 2004 23:34
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It really depends on the tuning. It sounds like you are using the standard ecu, so you will need to watch the A/F ratio's closely and push it as far as you can safely get it.
1G's are really cheap here, so people don't mind busting them to see how far they can go. The difference is that if they are going to go crazy, they use an aftermarket standalone ECU and tune it accordingly.
Once again, aftermarket ECU's seem to be a lot easier and cheaper to come by here than in America.
I know of a couple that are running 20-25 psi and making 300+ RWHP.
Let us know how it goes.
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Location:
newcastle nsw
Registered:
May 2002
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Re: 1g-gte max boost?????
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Wed, 18 February 2004 07:43
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email or pm toy77.
he tuned his car on the weekend, similar setup to yours t04 1g with standard comp ect. results are very surprising the ecu, inj and afm are not as limited as a lot of people think they are
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Location:
PNG
Registered:
June 2002
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Re: 1g-gte max boost?????
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Wed, 18 February 2004 07:51
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Motor sounds like a generation 1 if the injectors are yellow, so runs 7psi standard.
The injector are 225cc, note that if you go aftermarket on the computer or fit intercept module, you can fit the injectors off a 7mgteu which give you 430cc.
I run 14psi boost on mine and it still runs far too rich., and understand that they can take significantly more as long as you get the fueling right.
Craig
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Location:
Brisbane
Registered:
November 2002
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Re: 1g-gte max boost?????
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Wed, 18 February 2004 14:06
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I run 14psi boost on mine and it still runs far too rich., and understand that they can take significantly more as long as you get the fueling right.
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14psi is not 14psi. 14psi on two tiny turbos like the stock 1GGTE setup is nothing like 14psi on a bigger TO4 - guess which one will go better? The 14psi on the bigger turbo, of course.
And why? Because it's flowing a greater volume of air at the same pressure. The only trick - making sure there's enough fuel to go with the air, and that it is tuned correctly!
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Location:
PNG
Registered:
June 2002
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Re: 1g-gte max boost?????
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Wed, 18 February 2004 23:55
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nice to have physics redefined - so what you are saying is that if you have 14 psi of water going though the same tap, but one has a bigger pump the volume is the same? Course the T04 can flow more but you have to change more than just the turbo to flow more.
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Location:
Brisbane
Registered:
May 2002
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Re: 1g-gte max boost?????
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Thu, 19 February 2004 01:34
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7M-Brisbane is actually quite correct, although his explanation was somewhat simplified. It's a well-known fact that a larger, more efficient turbo will produce MORE power at LOWER boost. This is partly because of the greater adiabatic efficiency (ie less heat generated by the compressor) and partly because the exhaust side is less restrictive. It's all about flow, not boost...
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Location:
Perth
Registered:
October 2003
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Re: 1g-gte max boost?????
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Thu, 19 February 2004 01:42
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| ddeane wrote on Thu, 19 February 2004 07:55 |
nice to have physics redefined - so what you are saying is that if you have 14 psi of water going though the same tap, but one has a bigger pump the volume is the same? Course the T04 can flow more but you have to change more than just the turbo to flow more.
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Not at all, you can have 14 psi of water or air going through a tap/hose @ 14 psi and 10m^3/hr. Put a bigger pump on and you can achieve 14 psi and say 20 m^3/hr. Flowrate = velocity x area, so basically the water or air from the big pump is going twice as quick as the little, hence doubling the flow or amount of water/air coming out of the hose. More air in engine = more power, and generally quicker air velocity means more power and torque. The limiting factor being the faster the air the hotter it gets.
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Location:
PNG
Registered:
June 2002
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Re: 1g-gte max boost?????
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Thu, 19 February 2004 05:36
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Remember we are going through the same tap so area remains constant, velocity is defined by pressure, so velocity remains constant so same result! To improve flow I either have to increase area or increase pressure.
If I have the same opening, 55mm (my throttle body) and I pass air through it at 14psi the pump is irrevent, it just needs to achieve 14psi. Now if I was to double the opening the smaller pump may have problems maintaining 14 psi but the bigger pump may still cope.
Funny that wots happens on my 1ggteu!!! I get 14psi somewhere after 3000rpm and as I rev further the pressure drops off until about 7200rpm (where the limiter says stop) where it is about 9psi. That is I have moved passed the ability of the actual pump to deliver volume. Therefore the reason I am moving to a larger, more effective single turbo. But at 5000 rpm where they both deliver 14psi and hopefully the air temp is the same I would expect the same performance.
In fact as I am not happy to have the same performance I am increasing the diameter of the pipes and the Throttle body. Which makes me think - is other theories are correct - why would we ever think about bigger throttle bodies.
Craig
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Location:
Malaysia,Kuala Lumpur
Registered:
July 2002
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Re: 1g-gte max boost?????
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Thu, 19 February 2004 14:09
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On a limb here, but just curios. If i added 7M injectors (440cc)? on a standard 1G will the engine perform differently ?? or would i need to change ECU. Also what's the current injector size for the Gen 3 ??
Could i then add an aftemarket ECU and JZA80 injectors then for more top end power.
| Quote: |
Funny that wots happens on my 1ggteu!!! I get 14psi somewhere after 3000rpm and as I rev further the pressure drops off until about 7200rpm (where the limiter says stop) where it is about 9psi. That is I have moved passed the ability of the actual pump to deliver volume. Therefore the reason I am moving to a larger, more effective single turbo. But at 5000 rpm where they both deliver 14psi and hopefully the air temp is the same I would expect the same performance.
In fact as I am not happy to have the same performance I am increasing the diameter of the pipes and the Throttle body. Which makes me think - is other theories are correct - why would we ever think about bigger throttle bodies.
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Like what ddeane said. If a bigger diameter piping was added would that not increase volume of air = more torque/power ?
Just toying with the idea.
cheers
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Location:
Newcastle, NSW, Australia
Registered:
May 2002
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Injectors
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Thu, 19 February 2004 21:16
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Hi Jamie, how's business? Your site looks great. I've emailed Amber a few times but keep getting bouncebacks. I'll email you direct instead.
Dispatcher,
Yes, the engine would perform differently. It would bog down and use lots of fuel. It's a common misconception that the ecu (any ecu) will always adjust the injector cycle just because it has an O2 sensor. Apart from cruise and light throttle openings the efi system works in open loop and relies on the internal map. You generally only increase injector size if you can control the injectors with aftermarket or an interceptor module. Even then, you should only swap injectors if you really need the extra fuel.
You also have to be careful at fitting Gen 3 injectors to earlier models due to the difference in injector impedance.
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Location:
Perth
Registered:
October 2003
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Re: 1g-gte max boost?????
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Thu, 19 February 2004 23:52
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Remember we are going through the same tap so area remains constant, velocity is defined by pressure, so velocity remains constant so same result!
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True ddeane, bernoulli's equation will show that pressure is related to velocity, and density of medium. However this "tap" situation can't be applied to turbo vehicles, cause the outlet of the "tap" is indepedent of what is pumpung water through the tap on the inlet. Exhaust backpressure is the reason why a bigger turbo with 15 psi will make more power than a smaller turbo with 15 psi keeping all the inlet piping the same. The smaller turbo simply cant flow enough gas on the exhaust side, meaning no more air can be forced into the cylinder on inlet, e.g. bad scavenging. Perhaps this is the reason your boost is dropping off?
Increasing the inlet piping size, or throttle body will only make things worse as the air velocity will decrease, and the exhaust restriction will still be there with tiny turbos.
[Updated on: Thu, 19 February 2004 23:53]
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Location:
PNG
Registered:
June 2002
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Re: 1g-gte max boost?????
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Fri, 20 February 2004 05:58
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Not sure that we have said anything different. At the point where they are both delivering 14psi all is even.
Craig
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Location:
Perth
Registered:
October 2003
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Re: 1g-gte max boost?????
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Fri, 20 February 2004 08:16
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If you want to put it that way then, have more area on the exhaust turbine, is the same as making the outlet of the tap bigger, therefore in both cases the flow will increase at the same pressure. Hence why bigger turbos make more power at same psi as small, cause they flow more air.
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Location:
Brisbane
Registered:
November 2002
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Re: 1g-gte max boost?????
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Fri, 20 February 2004 15:19
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Which all comes straight back to my (simplified) explanation.
Given that the guy was asking a clearly uneducated "how much boost can this engine run safely" I thought a basic explanation was enough.
Oh, and I think you'll fin dthat 2JZ injectors might be a ittle tricky to get working on a 1G 
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Location:
Tuscaloosa,Al USA
Registered:
February 2004
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Re: 1g-gte max boost?????
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Fri, 20 February 2004 20:44
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Hey Grant, the business is going great and so is Amber's. She opened an advertising agency this month.
Thanks for all your help. Any of you out there heard of opening the AFM and increasing the flapper door spring tension when adding larger injectors, to help lean out the fuel mixture? Also I was thinking about installing the 360cc injectors from a Mitsubishi 3000GT/GTO into the 1G. They are low impedance and the fact I have them laying around. I know about the T04 turbo putting out more air volume, but would that cause a problem if I just kept the boost at 12psi and the injectors stock and upgraded the intercooler?
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Location:
PNG
Registered:
June 2002
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Re: 1g-gte max boost?????
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Sat, 21 February 2004 01:21
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20valve
I think that you will find that the amount of adjustment that you can get with change the AFM will be at the margins.
I have spent a bit of time on the dyno playing with mine and while I dont have a to4 to deal with I found that the motor ran extremely rich. The technican did not play with the 'flapper' spring but did try and correct some of the overly rich mixture through the adjustment that did exist. Remember the new injectors that you have in mind are about 50% larger than the original equipment. Maybe thing could be made to work at higher boost/revs but you run the risk of it running like a dog down low.
If I was you I would be tempted to put it on a dyno with a good mixture meter attached and get an idea of how it is behaving! You may be surprise - there may be good hp to be found with the standard injectors.
One thing that you may be interested in. When we were playing around we removed the hose that provides the 'raising rate' to the fuel regulator and carefully monitored mixture.
At the point where we just commenced to get boost we got to just over 14.2 (from about 12.9). But the real surprise is once it got on boost it changed from low 11s to low 12s. I picked up 13 kw at the wheels and it really smoothed out the power delivery. On shootout mode the dyno gave 140kw at the wheels. Note that with the tiny turbos by the time it got to max power at approx 7000rpm, boost had dropped away from 14psi which the wastegate was set at, to around 9psi. A problem u will not have with your setup.
Anyway just a thought if you do decide to try bigger injectors, although my gut feeling is that if you are happy to keep under 14psi with you new setup that things should cope.
Craig
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Location:
Malaysia,Kuala Lumpur
Registered:
July 2002
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Re: 1g-gte max boost?????
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Sat, 21 February 2004 04:47
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One thing that you may be interested in. When we were playing around we removed the hose that provides the 'raising rate' to the fuel regulator and carefully monitored mixture.
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Hose ?? what hose is this ??
i should look for a book titled '1G for idiots' (like me) 
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Location:
Cabramatta, NSW
Registered:
May 2002
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Re: 1g-gte max boost?????
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Sun, 22 February 2004 01:28
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| ddeane wrote on Thu, 19 February 2004 16:36 |
I get 14psi somewhere after 3000rpm and as I rev further the pressure drops off until about 7200rpm (where the limiter says stop) where it is about 9psi.
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I've never actually noticed this on any of my 1Gs. But maybe my (digital) boost gauge isn't fast enough to pick out the drop?
You've got a Gen2 don't you Craig?
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I supported Toymods
Location:
Northern Beaches
Registered:
May 2002
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Re: 1g-gte max boost?????
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Sun, 22 February 2004 06:05
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mine drops off boost too like that, hit max boost about 4k at 12psi then drops off slowly to about 10psi
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