The best turbo for a 998?
Turbo Mini Forums

Hi,
I am currently on the look out for the bits i need for my planned 998 turbo build. I had planned on using a T2 turbo for the build but they arent easily got locally, im keeping a look out on the fourm and ebay but got a brain wave the last day to use a turbo from a turbo starlet (glanza). Just wondering would one of these work, i want the turbo to spool up as quickly as possible but dont know much about it so looking for some advice.
Also as im on a tight budget,and a turbo from a turbo starlet would be cheaper.

Edited by jdisel on 16th Sep, 2011.

A job worth doing is a job worth over doing

What is the turbo on a Starlet? If you want to know if it will work you need to see if you can get a map for it.

Also if you need advice we need to know more about what you are building the car for, road, race, track. Power expectation.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

Thanks for the reply.
Probally should have been more specific. My plan is to build 998 turbo road car, i have sourced a good few parts but just want to make sure a T2 is the right choice. Hoping to get 90 to 100 bhp if thats achievable.
I did a bit of reading on wikapedia and i think the turbo is Toyota's own CT9. But thats as much as i know.
Is there another turbo that might suit that can be easily got.

A job worth doing is a job worth over doing

Something off a little turbo diesel that produces around the same power should be a good starting point for research.

A T2 will work well for what you want. I have a GT15 for my 998 build. I am hoping that it works as well, if not better than the T2.

If you do a search on sabre sprint you will find another turbo that will suit you needs.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

i've been doing a bit of reading and the gt15 looks better suited to me than the T2 and probally easier to get hold of.
Im looking for a fast spool up and from looking at other fourms and stuff the gt15 should spool up quicker than the T2 but correct me if im wrong.
Will a diesel turbo work well on a petrol car.
What car did you source your gt15 from Ben H.

A job worth doing is a job worth over doing

I don't know the history of my GT15, but more than likely it will be off a diesel. There is no problem using a turbo off a diesel so long as the map is what you are looking for. There is talk of them being made of lower quality material as they have to cope with lower temperatures. However, I doubt that you are planning to do 100k miles in your 998 so there is nothing to worry about. Mind you all that said and I bet nobody on here has seen a T2 without a big crack across the wastegate and people keep using them.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

I did have a gt1544 from a vaux diesel, pretty cheap to buy, they were on a lot of late 90's early 00's 1.7 and 2.0 astra's and vectra's etc. A lot easier and cheaper to source than a T2.

one day boost will be mine!

Probally go with a GT15 so. I cant figure out the maps yet but ill get reading and see can i make sense of them.

My plan was not to cut the bulkhead so is this possible with the GT15 with a custom manifold.

A job worth doing is a job worth over doing

The GT15 is physically very small so is no problem to get in. It will have to be a custom manifold as the manifold flange is not like a T3 or T2 flange.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

Any pics of the flange or comparison to the gt17 Ben? Might be an ideal candidate to replace the most likely goosed t2 on the old mans 998.

Edited by sturgeo on 18th Sep, 2011.

Getting the turbo and flanges made up is the next task. Im assuming it the GT1544 that wez mentioned that im after not the GT1548 because they have different maps and flanges.

Still havent conquered these maps but i think the GT1544 should spool up quicker than the GT1548. right?

http://www.turbobygarrett.com/turbobygarre...44_454082_2.htm

http://www.turbobygarrett.com/turbobygarre...48_466755_3.htm

Cheers for all the replies,

A job worth doing is a job worth over doing

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Ill keep my options opened a while because im in no panic with it.

Because its a road car i want to make it as drivable as possible, so the less lag the better,

Any ideas what sort of the rev range the the GT1544 is good for, as in when it will get full boost and when it will begin to loose its top end grunt.

A job worth doing is a job worth over doing

Very little data to go on, but on this forum there are rolling road graphs for the GT1544, T2 & GT1752 on a 998.

My own T2 comes on full boost by 4k and is still going strong at the rev limit. I would judge the Gt1544 and the Gt1752 to be on full boost 500rpm each side of that.

They should all pull well to around 7k, the Gt1544 turbo will feel torquier but will limit your headline horsepower.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Of course, if you want boost at 3k, then you should fit a supercharger and wear womens clothes :)

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

ha, ill stick with a turbo so,
dont think id look that good in womens clothes.

I still thinking a GT1544, not too bothered about a loss of a few horses if it will spool up a bit quicker than a T2. Plus i dont plan on hitting 7K that often.

A job worth doing is a job worth over doing

Well here are the details of the GT1544.

http://www.turbobygarrett.com/turbobygarre...44_454083_2.htm

It is a 44 that I have got and for a good fast road 998 I think it is perfect. I suppose I should plot the 998 onto it to see where it all falls. I will hopefully be building this engine in the new year and all results will be posted.

Edited by Ben H on 18th Sep, 2011.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

Im thinking the GT1544 will suit me too so im gona go with it.

Thanks for all the help lads, much appreciated.

A job worth doing is a job worth over doing

sorry to hijack a bit, but does anyone have a compressor map for an IHI-vf12 and vf17?

There is a little variation in the compressor maps for the Gt1544, T2 & Gt1752, but only a few percent. However, there are huge differences in the turbine performance.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

see my build thread linked below...

I ran the T2 in two set ups,
one was 8 psi about 10:1 compression
other was 13 psi 9:1 compression

the first was 80 bhp and very nippy but topped out at 5500 rpm (which may have been due to me running a dizzy so not having the correct timing),
the second is 110 bhp and has lost a bit of off boost power but pulls all the way to 7500 rpm and was still maintaing a flat power line at that point.

the 110 bhp car is lovely as a road car, you can potter around off boost but have the power there if you need it but you do have a bit of lag.
the 80 bhp setup felt like my 1275 but with a little bit more umph and the kick from the turbo.

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

if your unable to find a R5 T2, i used a non-water cooled T2 from a 309/306 turbo diesel.......

Im back with more questions, ha

Any ideas how i would plot my 998 on the GT1544 map,
I tried the instructions by garrett but cant make sense of it.

Im probally gona go with a GT1544 anyway but i still wouldnt mind gettin a grasp on these maps,

http://www.turbobygarrett.com/turbobygarre...bo_tech103.html

http://www.turbobygarrett.com/turbobygarre...44_454083_2.htm

A job worth doing is a job worth over doing

Right here is my rough plotting on the 44 and 48 maps for a 998. The lower flow point is 5k rpm and the upper one 6k rpm.

I would say that to make the most of the 48 you need a higher revving engine, but even then it's nowhere near as efficient as the 44. and you'll be getting full boost on the 44 from 3k I reckon, but more like 4k on the 48.

From driving our (very low geared) 998 with a GT1752, it would make a dog of a road car.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk