this thread should be continued... Read it and comment.

https://www.thirdgen.org/techbb2/sho...5&pagenumber=1

 

Mitsubishi Applications
Superchips Inc. offers Eprom upgrades for the following Mitsubishi vehicles :
1987-1989 Starion Turbo 2.5L

By today’s standards they were quite crude using two separate computers for fuel and ignition. The ignition computer does have a knock sensor but a diaphragm in the distributor controls the advance curve; rotating the distributor could move the timing curve.

The fuel computers have a boost limit at 12 PSI in the early cars and a little higher in the later cars and careful reprogramming allows the use of boost levels up to a maximum of 16 PSI. After this level, the injectors are fully open and the engines start to run lean with disastrous results. Due to the unusual injector design and the fact that there are only two of them, increasing the injector size is not possible, nor is increasing the fuel pressure a simple process due to the built in fuel pressure regulator / anti-surge chamber over the injectors.

At 16 PSI the cars can develop up to 210 HP, which gives them quite a healthy performance for an older design, but they will never have the performance of the latest cars due to the turbo design. In order to reduce turbo lag the cars have a small turbo fitted, which will provide significant boost pressure at 2000-2500 RPMs and makes the cars very controllable.

Unfortunately, the turbos cannot supply enough air at 5000 RPMs to develop a high horsepower figure but the mid range torque on the cars increases by 30-35% at 4000 RPM making the mid range acceleration quite breathtaking. The fact that the boost dies off over 5000 RPM minimizes the potential for a damaging situation due to high boost and high RPMs and this looks after the engine.

The kit consists of an ABC circuit; bleed valve and the necessary hoses and clamps. Unfortunately due to the ABC circuit the whole unit does have to come into us to be modified. We then install the ABC inside the computer. There is no extra installation costs and re-installing your computer won’t take up a chunk of your time, you probably wont even get your hands dirty.

If you wish to send in your computer we suggest you get the code from the ECU found in the passenger side kick panel. Call us to verify we have that code on file. Once confirmed safely pack your computer and enclose your name, address, daytime phone number, the year, make and model of the vehicle plus a method of payment. We suggest shipping the computer to us overnight and the day we receive it we will make the modification and ship it back overnight. All of our products come with a 30-day money back guarantee and a lifetime warranty. So why not check your code and give us a call at 888-CAR-CHIP.


some of that sounded familiar. darn.

 

Would you believe that I OWN a '88 Conquest also?! Just my luck that it happens to have TBI system.. I was looking into this Super Chips modifcation for the car until I had a littlle setback that put it out of commission... I hope to get it running again within the next couple of months... Parts are freaking expensive for this car!!!

I overheated (blew a heater hose) and scewed up the seal between the head and the block (essentially warped the head) this lead to a lean condition on #4 piston. which eventually cooked it while driving at high speed on the expressway... (REMEMBER IT IS A FUN CAR UNDER BOOST,,,)

check out the pics....


http://briefcase.yahoo.com/bc/shou38...ase.yahoo.com/

I'll get it fixed soon enough...

 

Why was this thread closed?

Your link is not complete there Snuf.....

 

Snuf, does this mean that you've started work on your tbi again?

 

The GM performance 383HT made 325hp and 414lb-ft with tbi. Anyone have more info on this setup? I'd like to see what exactly they were using to achieve the rating.

Snuf, how about making this a sticky post.

The only reason I can think of for this topic to be closed on the DIY Prom board is that it really wasn't prom related.

Steve

 

why closed. there used to be a lot more posts inthere, that were voluntarily deleted. and there were requests to close it, i requested to have it moved, never happened, soooo. here it is.

anway. yes i have been working on my tbi ever since the idea began, never stopped, just ran out of time and money, so all the thinking has been in 3d autocad realm. I now have the pod partially in 3d solids too. so that i could visualize more, but now i just want to rebuild the pod too. and now that ive cut apart an injector, i think i could even redesign that. The injector casing could be helped so that it could better match a newer larger resiviored (sp)? injector pod. etc... i should just write my memiors of tbi LOL.

I am strongly thinking about puttin my new 355 in my 92 instead of the 69 now since i will soon be driving a demo instead of my car. I also need to do body work on the 69 before i ever think of puttin a new engine in it. IF i do this, i will be pushing tbi FARTHER. with the help from all the people who enjoy it, I will also be throwing it the face of the naysayers to quote a fellow tbi'er. (Jon )

so, I will keep everybody updated again, and we will continue thinking of ways to push the tbi envelope.

good luck see everybody in a bout a week, my internet connection will die for a while, while i move. later

 

I'll probably get flamed for this but here goes. I guess its nice to have a formula to help chose injector size based on hp, but I have a problem with sombody putting limits on HP based on this formula. Or based on your injector size at one given PSI. There are other factors to making HP. What about things like longer conecting rods or higher compression ratio?What about fast burn head technology? I have an article in front of me on rocker arms. They found (on a dyno) 17 more HP at 6000 rpm using full roller rockers of the same ratio as a set of stockers.

I realize that the origional post delt with how much HP TBI could support. I just have trouble with some one telling me that I have xx pounds of fuel and I can't possibly make more then xxx HP with it no matter what I do. If every one thought that way TBI would have died along time ago. But it didn't, and it has got better. And it will continue to get better as long as people put there minds to improving it instead of why it won't work.

I guess part of the reason I am posting this is so people don't look at a formula and give up. There are other variables.

 

Ehhh joker, keep reading you have to understand how it all works

basically, fuel = hp depending on the efficiency.. efficiency can be affected in many ways but generally you wont find a street engine doing much better than .45 BSFC basically meaning you consume .45 lbs of fuel for every hp produced thats how we find how much an injector can support..

just do more reading on the net on the subject

 

Holley Projection fuel pump flows:

410 #hr of fuel at 15 PSI.

410#hr / 6#hr (weigh of 1 gallon of gasoline) = 68.3 gph (gallons per hour)


With (4) 85 #/hr injectors, this is enough fuel to support 500 + horsepower as seen in the following:

340#hr(sum of injectors)/6#hr = 56.6 gph.

500/6 x .5 x 1 = 41.67 gph

What do you think stock TBI fuel pump and injectors flow? I don't know how much power you're shooting for. The stock equipment has limits.

Joker, an engine is nothing more than a glorified air/fuel pump. The things you speak about increase area/displacement, which means nothing unless you pump more air/fuel into the engine...


A fuel system is just that - a system! All the pieces must work together. The current trend is to run a pump that is much bigger than should be required to compensate for deficiencies within the system. Simply buying and installing the biggest pump you can find will not be enough if the rest of the system is poorly thought out. The same can be true buying a pump based upon price or what you think is enough fuel pump. Either deficiency can also easily drain the wallet if you run out of fuel and start damaging engine parts ... not to mention losing races!

This article will focus on electric fuel pumps. Mechanical fuel pumps are not worth the effort unless you are mandated by the rules of your class (as in most circle track applications). You can use the same basic knowledge with your mechanical fuel pump in regards to requirements and fuel regulator choices.

Fuel pumps are generally rated in gallons per hour (or GPH). Of the two type of electrical pumps available, gerotor style pumps are quieter and more efficient than rotary vane style pumps. However, it is mandatory that a fuel filter be installed between the fuel cell (or tank) and the pump. The higher efficiency of the gerotor pump also is less tolerant of garbage getting into it, always run a filter before the pump! You should also have a filter just before your carburetor or injector rail as well.

A typical engine uses 0.5 pounds of fuel (gasoline) per hour to make each horsepower. Gasoline weighs in at approximately 6 pounds per gallon. To calculate fuel consumption let me show you by example. Lets say we have a 400 HP engine (or nitrous system) and we will use the following formula:

400 HP X 0.5 X 1 gal = 33 GPH
HP per hour 6 lb.
If you installed a pump rated at 33 GPH on a 400 HP Nitrous system the engine would experience severe fuel starvation.

There are several reasons why fuel starvation would occur, however the main reason is the way that pumps are rated. Fuel pumps are rated at "zero" pressure (also known as "free flow"). Rating a pump at zero pressure is useless because the pump will never be at zero pressure when it is operating in the vehicle. As fuel pressure increases, the fuel pump slows down and fuel output is reduced. If you use a standard "dead-head" type regulator, the pump may be forced to produce as much as 25 PSI. At 25 PSI, the actual output GPH of the pump is much less than at "free flow".


to learn more check out this web site:

www.forgedperformance.com

there is lot's of good info. plus a pic of my ride in the photo section...