What Turbos can I Use?

[Racer88]

Hey guys,

I am new here and am doing the MK1.5 build for my 88 MR2 and have a turbo question. I was given a new 14b turbo from a 1st gen eclipse and was wondering what it would take to mount this turbo to a 3sgte motor? Is there already a walkthrough for something similar or has anybody else done a swap like this? Thanks.

[PHOENIX]

Since your using the 3s engine.....check out the links inside this link...

Learn about getting power from your 3S-GTE here!

Welcome

[328FTW]

What happened to the stock turbo? If you are looking at it as a way to bump up an n/a to make a 3sgte engine on a budget it would work well but not sure about substituting for the 3sgte's turbo, It would not perform hugly different from stock imo. They are cheap and plentyful though. I did read one post on the celica forums about some guy using a 14b at 14psi but no numbers or anything it was just what he said he was running. Also remember the 14b is not that great above 16psi.

I am about to adapt a turbo onto my gen 2 3sge and run it at ~8psi to get some more hp. All depends on your goals I want a quick spooling turbo for the type of racing I use the car for. If you are sure you want to fit it just make an adapter between the two different manifold patterns and fit it on and do the piping (easy to say). You will also need the dump pipe and a way to fit that to an exhaust system.

Check out the link PHOENIX posted to learn a little about how the turbo system works, there is a lot more to turbos than those that claim things like "bigger is better" and "more boost = more horsepower" those statements are not true for most applications and you need to know what you want before you decide to fit a turbo to an engine.

[Racer88]

thanks guys. I am building this for roadracing out in california. Mainly Infineon Raceway and Laguna Seca.

[Parkins]

How about a ct26 turbo off a supra? Could I make that work in an 86 with a 4AGE?

[328FTW]

Originally Posted by Parkins

How about a ct26 turbo off a supra? Could I make that work in an 86 with a 4AGE?

Yes but it is a pretty big turbo. It is a single entry turbo not a twin scroll like the mr2 ct26 twin entry turbos. I would say it would lag a little too much unless you intend to pull some serious revs out of the engine. They are heavy as well, I would go with a smaller turbo off a mitsi or something.

Here is an answer from another forum.
Club4AG Forum Topics: 4agt W/ct26?

[Parkins]

idk if i like the whole thanks post thing above this... haha
but thanks alot! that was definitely helpful, exactly wheat i was looking for

[mhamrick]

I'm new but not to MR2. If you are going to use this as a straight race car ONLY then you might be OK with the CT26 off the Supra. Yes it is going to lag but it will make one sick nasty top end. If say you started boost at 3k and had 10 psi by 4k then it would almost be ideal for your car. That is if you are only going to race it.

Also T3/T4 would be a good match for you. Not a junky eGay one but a real one made from Garrett or another Reputable Manufacturer.

[328FTW]

Depends on what type of road racing as well. For tight twisty roads you want a quick spool up to get to the next corner without having to worry about lag and a big turbo with lag can make cornering harder because it will light up the back wheels part way through a corner unless you control that somehow. Part of the reason I am going with a small turbo on my car I race gravel and I want more horsepower but I can only put so much to the ground and want to have good throttle response to not fly off the corner because I was waiting for the turbo to spool.

And yeah those eGay ones have about a 50% failure rate when used under real conditions, stay away from them the drift guys use them on their cars and blow them up straight away.

[mhamrick]

328FTW- You would have probably done better with a SC14 but a small turbo is fine too.

I agree with you to an extent on this topic.If he is worried about pulling off mid corner and does not want to break the rear end loose then yeah I agree. But he can have the same effect with a big snail also. Big turbos come on and come hard when they do. However a large turbo at 7psi can make as much as 100hp difference compared to a small turbo at the same psi. When racing this is a good thing because you will avoid heat soak in the Intercooler that a small turbo working its rear off will make. That is why you want to look at a compressor map and see where it efficiency islands are and find one that you are in its efficiency range in the RPM load you will most be using. This way you do not have a large expensive Hair dryer because you can turn a turbo into one very easily.

The other part where this is going to hurt is pulling on straights. The idea would be to keep the car in the boost (lets say the psi starts at 4k) and when exiting the turn be right in this area. A car with say a T3/T4 will rip a T3 out of a turn at the same RPM because you will be hitting the Big turbos efficiency where as the small turbo will be moving out of its efficiency. When driving a car on the track (paved of course) you would want to keep the car wound up anyway. Look at most NA cars and even those stay in the higher RPMs.

Basically when you build a turbo car you think of what you are going to be using the car for. If it is daily driving then you need to build it for the RPMs it will be used in. Most people drive their car in the 2k to 5k range. You would want a smallish turbo that starts boosting at 2k for this app. On a track car most of the time you are going to be in 4k and up. For that you will want to run a turbo that is spooling at 4k and running max by 5k but still in its efficiency range at redline.

If you build a turbo track car with a small turbo you are going to get outrun by a car identical but with a larger snail. However if it is on a track that is all turns then a small turbo may be better suited. However most tracks have more straightaways then turns. If you are going to use the car for both street and track then you will want to split the difference between a big and small turbo. A super 60 will put you in a good spot for not to much lag and still pull good at the top end.

Hope this helps..................

[328FTW]

I'm using a small turbo for a number of reasons. I am familier with the large turbo efficiency etc etc but I am also poor and can't afford a larger turbo, sc14 are hella expensive as well I couldn't find one cheap. I have spent $150 on the turbo setup thus far without including the stand alone which I can reuse on other projects. 100 of that was a good condition turbo, 20 on the manifold.

Plus Mine is an n/a engine with the high comp pistons so I can't run high boost so the smaller turbo won't be working to keep up, the only issue is the reduced flow at high rpm will mean there will be a high backpressure in my exhaust from the restrictive exhaust wheel meaning at 5500-6000rpm it will hit the wall. This car will be focused on rallying so a small turbo is perfect anyway because my only advantage thus far has been my cornering and corner exit speeds. If I get into a horsepower race I will lose, there are guys at my club running 400hp v6 supercharged engines, they are heavy though I brake then throw the car like a madman to keep up so if I had any hesitation I would be in the trees. Good stuff all the same though there are plenty of misconceptions about turbo setups out there and well researched info is hard to come across.

[mhamrick]

If you are going to rally then a small turbo is definitely best. I would go with a small turbo over a sc14 anyway but if you can get the SC14 to mount up and run right they are wicked.

I was not trying to say you were not right in what you posted as I understand completely what you were saying and agree. However there is 2 ways to skin a cat and it will boil down to what he is actually going to use the car for. I was just wanting to clarify it a bit is all.

To be honest I am getting ready (as in I have the parts) to do a T3 50 trim and I may be wishing at the end that I went GT17 or T25 T28. It is what I have (though I actually chose it) and it is rebuilt to new so it would only make sense.

[regisbou]

Sweet Infineon Raceway!

I went to the Jim Russel racing school there and the only advise I have for you is keep that throttle on turn 6...left downhill turn before you become parallel to the dragstrip.

Other than that the track is pretty self explanatory!

Yea and a small turbo is prefered on that kind of track too, same with leguna seca...the corkscrew will screw you up with a late boost turbo.

Good luck on your build