Max torque for 16v turbo

[fletchbog]

I put this on 106 owners but I think more boosted guys hang out on Saxp;
With respect to a TU5J4 16v turbo conversion - from searching, most people tend to suggest going with a 7-8 PSI limit but the problem with that is the amount of air a turbo can flow obviously varies with it's size. e.g. 7 PSI on a GT17 != 7 PSI on GT28.

Am i right in saying a 50% increase in peak torque is a sensible compromise between longevity and power to aim for with standard compression? ie. ~220ft/lbs

(The spec would be on bigger injectors, intercooled with tight control on intake temps, ignition advance, 98+RON fuel.)

[Dave_P]

A 50% increase in torque will kill a MA box pretty quickly.

[craigyt]

14psi on a gt25 @ 270lb.ft but iv got arp rod bolts with 1mm decomp

[fletchbog]

A 50% increase in torque will kill a MA box pretty quickly.

BE4 conversion will be on the cards Dave

[fletchbog]

14psi on a gt25 @ 270lb.ft but iv got arp rod bolts with 1mm decomp

Yeah I'm talking standard compression Craig. I am wondering if a GT25 would be a good idea for say half a bar of boost, but need to check the compressor maps and specs .

[craigyt]

I used to run at 7psi no probs, spools up nice n fast. Mates got a gt17 on and he does 6psi and that comes on boost quick as well

[sje00]

Pretty sure the BE boxes were only rated to something like 200lb/ft.
But as long as the torque delivery is smooth and you have some mechanical sympathy, you can make the boxes last.

[welshpug]

true, but better than a box that shits itself on a standard 1300 :p ma limit is 120 lbft btw.

[fletchbog]

That on a standard engine?

Turbo choice is still up in the air. Those 2 turbos will flow a significant difference in air at the same pressure.

I've read reports of the GT1752, making 200bhp or thereabouts without a decomp plate which would be perfect, but might be generating a lot of heat, potentially causing problems on track.

A GT25 of appropriate spec would allow me to run more boost in future by adding a decomp plate. What spec GT25 do you have Craig? If like you say it boosts nice and early on the J4 at low boost it could be the one to go for.

[fletchbog]

true, but better than a box that shits itself on a standard 1300 :p ma limit is 120 lbft btw.

Thats the idea! It's seems like a sensible compromise between cost/reliability

[Ross]

If you're talking about "on track" why does quick spool matter? You'll be at the upper end of the rev range anyway.

The MA box wont cope with decent power. They fall apart with stock power. A diff wont really help so dont bother - it'll just be an expensive lesson, and one you wont be able to take to your BE box.

As Sonny said, the BE boxes aren't great either but are miles better than the MA. Use mechanical sympathy, don't launch too much, and BE's are good for pretty big power - but the main benefit is they're cheap and the range of ratios is vast if you end up wanting to change them. Go BE, fit a plate diff if you're on track a lot, and enjoy it. If the box blows up, pop the diff out (15 minute job) and bang in another BE box. Simples :)

[fletchbog]

If you're talking about "on track" why does quick spool matter? You'll be at the upper end of the rev range anyway.

Because it will be 75% road car, 25% track car.


The MA box wont cope with decent power. They fall apart with stock power. A diff wont really help so dont bother - it'll just be an expensive lesson, and one you wont be able to take to your BE box.


I know, as said, BE4 conversion on the cards


As Sonny said, the BE boxes aren't great either but are miles better than the MA. Use mechanical sympathy, don't launch too much, and BE's are good for pretty big power - but the main benefit is they're cheap and the range of ratios is vast if you end up wanting to change them. Go BE, fit a plate diff if you're on track a lot, and enjoy it. If the box blows up, pop the diff out (15 minute job) and bang in another BE box. Simples :)

That's the plan mate. Any recommendations whether to go Gripper, TransX 3J or Kaaz?

[Ross]

Because it will be 75% road car, 25% track car.
Then build it for the road, not for track. A smaller turbo on track wont produce excessive heat - so long as you don't go mad winding the boost up. On it's efficiency island you'll be fine.

I know, as said, BE4 conversion on the cards
I'm reinforcing what others have said. Someone will be along at some point in your posts here or on moaners to suggest putting a diff in an MA box. It's pointless.

That's the plan mate. Any recommendations whether to go Gripper, TransX 3J or Kaaz?You'll probably find gripper to be the most used in the BE boxes (I'm guessing but from my own research 5+ years ago this was the case). The support from Dave Mac was second to none. I'd recommend them on that alone.

[sri_130]

I run a GT17 @ 6/7PSI @ 180hp. Getting it to run more would put it outside the efficiency window accoring to Garretts compressor map and increase inlet temps. The GT17 is perfect for low boost, relatively moderate power and is willing and able to spool really early - I think its underrated to be fair.

With stripped internals (if its a partial track car) and standard compression, the GT17 has got to be a contender, for track fun. Finding the GT25 is pretty tough, but 17's are on Saabs (IIRC) and I've seen a couple on Ebay over the past quarter.
I've decided to go middle to better ground with a GT2259, but its a relative unknown until its on...

[fletchbog]

I run a GT17 @ 6/7PSI @ 180hp. Getting it to run more would put it outside the efficiency window accoring to Garretts compressor map and increase inlet temps. The GT17 is perfect for low boost, relatively moderate power and is willing and able to spool really early - I think its underrated to be fair.

With stripped internals (if its a partial track car) and standard compression, the GT17 has got to be a contender, for track fun. Finding the GT25 is pretty tough, but 17's are on Saabs (IIRC) and I've seen a couple on Ebay over the past quarter.
I've decided to go middle to better ground with a GT2259, but its a relative unknown until its on...

That what I was effectively trying to say re pushing a small turbo - heat management on track can become an issue if it's operating near it's limit when combined with heat from the brakes, radiator etc.

I'm still in the process of choosing a turbo but I must agree from my research that the GT22 sounds like it would fit the 16v well, just a shame there's not much info out there from people that have used on on this engine before.

[sri_130]

That what I was effectively trying to say re pushing a small turbo - heat management on track can become an issue if it's operating near it's limit when combined with heat from the brakes, radiator etc.

I'm still in the process of choosing a turbo but I must agree from my research that the GT22 sounds like it would fit the 16v well, just a shame there's not much info out there from people that have used on on this engine before.

Its not so much the heat management output of the turbo housing itself, but the inlet temps are increased when the smaller turbo is asked to compress above its comfortable operational window - a good inter-cooler setup will alleviate some, but the run+room Vs 7psi negates the boost hike IMO.
As I'm not actively monitoring the inlet temperature (and on standard internals) you run the risk of melting the stock pistons - granted some can be alleviated by running a richer mixture also, but it does start to sound risky and increase considerations... when a more suitably sized turbo can be purchased from the outset. As you've already mentioned potentially wanting to hike up the power + addition of a decomp, if you're not happy with 180ish hp, then you're right to consider a 25.

I've not seen a 106 or Saxo use the 2259, so maybe I'll be the guinea pig! most tend to stick with the 25 or 28, (barring the early stage Cituning ones with the 17) and I'm sure I've researched a TD04 at some point...

Worth checking out MX5 boost projects, as similar size and output engine with probably a few more scientists on there experimenting with what works best?

[fletchbog]

Its not so much the heat management output of the turbo housing itself, but the inlet temps are increased when the smaller turbo is asked to compress above its comfortable operational window - a good inter-cooler setup will alleviate some, but the run+room Vs 7psi negates the boost hike IMO.
As I'm not actively monitoring the inlet temperature (and on standard internals) you run the risk of melting the stock pistons - granted some can be alleviated by running a richer mixture also, but it does start to sound risky and increase considerations... when a more suitably sized turbo can be purchased from the outset. As you've already mentioned potentially wanting to hike up the power + addition of a decomp, if you're not happy with 180ish hp, then you're right to consider a 25.

I've not seen a 106 or Saxo use the 2259, so maybe I'll be the guinea pig! most tend to stick with the 25 or 28, (barring the early stage Cituning ones with the 17) and I'm sure I've researched a TD04 at some point...

Worth checking out MX5 boost projects, as similar size and output engine with probably a few more scientists on there experimenting with what works best?

Good shout RE the MX5 lot, I know a guy whos into his MX5s whos considering boost so I'll have a chat with him to see his approach.

One thing I've noted with the 2259 is they tend to be used a lot on diesels so check you're getting the right spec that can handle the higher EGTs of petrol.

Inlet temps are so critical for standard compression I'm definitely going to get some temp sensors on there for peace of mind and to catch it early if it starts rising.

I'm trying to avoid going too mad on this project but almost tempted for water/meth injection. Lets not run before we can walk though...

[welshpug]

most widely uysed diff in the BE boxzes are Quaife, then Tran-x who are now owned by 3J but the MD of tran-x started a new company up called 3J driveline and are also producing Plate diffs.

[craigyt]

That on a standard engine?

Turbo choice is still up in the air. Those 2 turbos will flow a significant difference in air at the same pressure.

I've read reports of the GT1752, making 200bhp or thereabouts without a decomp plate which would be perfect, but might be generating a lot of heat, potentially causing problems on track.

A GT25 of appropriate spec would allow me to run more boost in future by adding a decomp plate. What spec GT25 do you have Craig? If like you say it boosts nice and early on the J4 at low boost it could be the one to go for.

Im not 100% to be honest, does gt2546 sound right? It was an ex severn valley ax project they started but never finished as was recomended by nortech to run it.

At 14psi i get full boost by 4k and at 7psi it was 3-3.5k rpm if i remember right!

[fletchbog]

Not the GT2554R then?

[craigyt]

Possibly, not sure, its been that long since iv had a goose at it

[mishoka]

I have same boosted car with TD05 16g i think is not verry small turbo so i drive it on two setup of boost 0.6 and 0.9. On 0.9 bars i have 260whp and 300NM, on 0.5 210whp the engine is fully stock, only have 1.9mm headgasket. The problem it comes when you starting to breaking the boxes like chocholate...Think for BE box first after that boosted..

[axsaxoman]

ma g/boxs falling apart is over estimated if
1 the car is driven with some mechnaical sympathy==not just spinning wheels for fun which will cause dif to explode eventually
2 fit an lsd this solves most problems
3 the box is not half buggerd to start with
if only using std internals +8 psi == clutch will be first thing to slip
4 fitting be conversion is not bullet proof ether if you drive it like you stole it
out of over 50 s/c conversions i have done or sold virtualy none of them have BE conversion and most are well over 200bhp @wheels
bad drivers do more damage than anyting ==or peopel saying i,ve had 3 new g/boxs when they mean they have fitted 3 old shagged boxs from a scrap yard
i have never had an ma box i heve rebuilt destroyed by either s/c or turbo -- so look after it drive sensible and save your money on conversion

yes at mega power box is not the best -- but the BE is not unbreakable either

[axsaxoman]

if its for road use then anything at 200+at wheels is all you need --yuo still got ot get it onto the ground --making mega car with lots of lag just means you wont come out on anything but a very dry day cos of the horrible way it will spool up and break traction --
200ish will make all your decisons easier and less problems.less lag and nicer overall drive

it is also a common mistake that you need to lower comp for modest boost --up to 10si --just get a proper ecu solution
all std modern turbo cars run 10-1 comp ratio --and up to a bar of boost --so why would you want to lower it down so its got no power when off boost --just sort the mangement and turbo size correctly so you dont, get the sudden spool up which will cause the detonantion cos the fuel+advance settings cannot cope with sudden boost spikes that you get with a laggy turbo
if you going for 300+then thats adifferent story --so plan properly before doing anything.

[craigyt]

Thats one thing i wish i had done different, stuck with one headgasket instead of 2 and a decomp!!

[mishoka]

if its for road use then anything at 200+at wheels is all you need --yuo still got ot get it onto the ground --making mega car with lots of lag just means you wont come out on anything but a very dry day cos of the horrible way it will spool up and break traction --
200ish will make all your decisons easier and less problems.less lag and nicer overall drive

it is also a common mistake that you need to lower comp for modest boost --up to 10si --just get a proper ecu solution
all std modern turbo cars run 10-1 comp ratio --and up to a bar of boost --so why would you want to lower it down so its got no power when off boost --just sort the mangement and turbo size correctly so you dont, get the sudden spool up which will cause the detonantion cos the fuel+advance settings cannot cope with sudden boost spikes that you get with a laggy turbo
if you going for 300+then thats adifferent story --so plan properly before doing anything.

I follow this advice and make my everyday road car only with 1.9mls head gasket from GMC, and 13psi ms2 and 260whp its awesome spools in 3000rpm and on 4000rmp i have full boost i can say the car is verry fast for road but i think over 200whp you will need BE box.

[fletchbog]

Even 200 at the fly would be plenty for me. Would be a sensible compromise between a lot of fun and reliability. I'm not one for chasing pub figures and that is still 80bhp up on standard. Just need to size a suitable turbo now :y:

[Nimix]

What manifold an ecu are you guys running?
I'm thinking on getting the t25/28 .86 upgrade for s13/14.

http://www.ebay.co.uk/itm/T25-T28-T25-T28-TURBOCHARGER-NISSAN-200SX-S13-S14-TURBO-/400241312014?pt=LH_DefaultDomain_3&hash=item5d303dc10e

[axsaxoman]

I follow this advice and make my everyday road car only with 1.9mls head gasket from GMC, and 13psi ms2 and 260whp its awesome spools in 3000rpm and on 4000rmp i have full boost i can say the car is verry fast for road but i think over 200whp you will need BE box.

I am hoping you have a wide and lambda fitted so you can keep an eye on the fuelling --running lean on std pistons will destroy them very quickly .
your next up grade should be an AEM fic controller ,then you can alter timing and lots of other things when on boost but have the nice std running when off boost -- ms2 can only do half the things an FIC controller can --
basically it can nearly do everything a stand alone can do --but alot cheaper and you only alter things where you need to to --so is simpler for msot DIY men.
a good choice for a turbo for this type of power would be a std evo one ,good for 320 bhp --downside is it sits other way round ,so you need to make your own manifold --upside is it spools up very quick and is very compact .
std evo can make 1bar +at 1800rpm --so even if its is 2500rpm to get a bar on smaller engine still very good-- a bit of boost control and you will have a very nice road car

[Nimix]

I am hoping you have a wide and lambda fitted so you can keep an eye on the fuelling --running lean on std pistons will destroy them very quickly .
your next up grade should be an AEM fic controller ,then you can alter timing and lots of other things when on boost but have the nice std running when off boost -- ms2 can only do half the things an FIC controller can --
basically it can nearly do everything a stand alone can do --but alot cheaper and you only alter things where you need to to --so is simpler for msot DIY men.
a good choice for a turbo for this type of power would be a std evo one ,good for 320 bhp --downside is it sits other way round ,so you need to make your own manifold --upside is it spools up very quick and is very compact .
std evo can make 1bar +at 1800rpm --so even if its is 2500rpm to get a bar on smaller engine still very good-- a bit of boost control and you will have a very nice road car
Let me get this straight.
Buying a Fuel/Ignition controller is enough to get the engine running with the stock ecu (assuming internal wastegate on the turbo) instead of changing the entire wiring to run an aftermarked ecu?

[mishoka]

I am hoping you have a wide and lambda fitted so you can keep an eye on the fuelling --running lean on std pistons will destroy them very quickly .
your next up grade should be an AEM fic controller ,then you can alter timing and lots of other things when on boost but have the nice std running when off boost -- ms2 can only do half the things an FIC controller can --
basically it can nearly do everything a stand alone can do --but alot cheaper and you only alter things where you need to to --so is simpler for msot DIY men.
a good choice for a turbo for this type of power would be a std evo one ,good for 320 bhp --downside is it sits other way round ,so you need to make your own manifold --upside is it spools up very quick and is very compact .
std evo can make 1bar +at 1800rpm --so even if its is 2500rpm to get a bar on smaller engine still very good-- a bit of boost control and you will have a very nice road car
I dont have any lambda sensors but i have good maper so my car is still alive after 10k miles. I have lean fuel ibut the problem it was OEM fuel pump cant pump enought fuel so i have AEM and is fine. I will check this AEM fic control.
And yes the car is verry nice for road and track.

[axsaxoman]

Let me get this straight.
Buying a Fuel/Ignition controller is enough to get the engine running with the stock ecu (assuming internal wastegate on the turbo) instead of changing the entire wiring to run an aftermarked ecu?

yes that is correct

[axsaxoman]

I dont have any lambda sensors but i have good maper so my car is still alive after 10k miles. I have lean fuel ibut the problem it was OEM fuel pump cant pump enought fuel so i have AEM and is fine. I will check this AEM fic control.
And yes the car is verry nice for road and track.

mega squirt can run lambda so why not use it ? can even run a w/band unit so yuo can control full fuel map
what size injecotrs you using ? and at what fuel pressure
std genuine good conditon pump --presuming it is a 16v pump --not a 1.4 pump can flow enough fuel at 3 bar for your boost +power
lifting fuel pressure above 4 .5 bar will drop flow as pump gives mch more flow volume at 3 bar --thats why injectors are rated at 3 bar - 490cc injectors are plenty big enough -- whats your injector duration --should be below 80%

[stevo1600]

Thanks axsaxo man for the above posts, you have answered some of the questions i needed to ask myself.

Great, experienced bloke right there.

[stevo1600]

I have a few questions whilst we are kind of on topic.

Will lowering compression, using a 1.9mls head gasket, reduce the risk of detonation? - the reason i ask is because most of the builds i have seen, including my vtr turbo, everyone said "lower the compression" is it a good idea, or a stupid idea?

Is 200@wheels achievable with std compression on a 106gti engine?

Also, im looking at the Saab 9-3 9-5 Eco Turbo B205 B235 Garrett GT17 - Would one of these spool quick? and would it see me 200@wheels?

And finally, your thoughts on a gt25 turbo which i have no idea what cars they came off, but many seem to pick this turbo?

[Sophia_Bush]

i never lowered cr on any of mine just had the map done properly, got a t25 off a 9-5 for mine

[fletchbog]

I have a few questions whilst we are kind of on topic.

Will lowering compression, using a 1.9mls head gasket, reduce the risk of detonation? - the reason i ask is because most of the builds i have seen, including my vtr turbo, everyone said "lower the compression" is it a good idea, or a stupid idea?

Is 200@wheels achievable with std compression on a 106gti engine?

Also, im looking at the Saab 9-3 9-5 Eco Turbo B205 B235 Garrett GT17 - Would one of these spool quick? and would it see me 200@wheels?

And finally, your thoughts on a gt25 turbo which i have no idea what cars they came off, but many seem to pick this turbo?


Most of what you ask has already been answered on this thread already.

Lower static compression will allow you to run more boost, but the engine will be less responsive off boost.

It has been said already 200bhp atw is easily achievable on standard compression providing you have good control of fuelling, ignition and intake temps.

[axsaxoman]

replacing std gasket with a 1.9 mm will lower comp ,but not that much
owever fitting decomp late = then thicker gaskets will lower it far too much for best all round performance .
you still will have std rods =cast pistons -- so the level of boost must be sensible --as to how much powr std pistons can take for sure --i would not be so brave as to say they are bullet proof at 200@wheels --200 @fly they should be fine
lowering comp too far does not make things any stronger
as has been said it is an attempt to stop detonation spikes caused when a turbo spools up very quickly

[stevo1600]

Then thats all i needed to know, im going to be fitting a 1.9 mls hg anyway, in fact ill throw up the main parts im going to be using - this is for a pure road car, let me know your thoughts, whether its a good spec, shite spec, or things i could do with changing/adding or removing. Of course all the small parts are not on this list. ie oil feed/drain etc. my aim would be 200@fly.

ci-tuning turbo manifold/downpipe
turbo = gt17 or gt25, gt28rs?
injectors 490cc (IWPO69)
4bar fpr
walbro 255 fuel pump
predator ecu
intercooler
2.25" boost pipe's
2.5" exhaust
boost gauge
AEM wideband afr gauge
oil temp gauge
oil pressure gauge
mocal oil cooler kit
1.9mm mls hg
helix paddle clutch
ma gearbox

[craigyt]

Im on standard ecu and a nortech manifold

[iSlayeR]

I'm using a gt17 turbo off a Saab, and a single 1.9 h/g and I find the power delivery is very smooth through the rev range :y:

[Gabbastard]

Id always been tempted to do a low-boost setup on my AX. Tbh, its pretty quick with just the 16v engine so a quick spooling turbo setup would be more than enough for most roads.

[mishoka]

mega squirt can run lambda so why not use it ? can even run a w/band unit so yuo can control full fuel map
what size injecotrs you using ? and at what fuel pressure
std genuine good conditon pump --presuming it is a 16v pump --not a 1.4 pump can flow enough fuel at 3 bar for your boost +power
lifting fuel pressure above 4 .5 bar will drop flow as pump gives mch more flow volume at 3 bar --thats why injectors are rated at 3 bar - 490cc injectors are plenty big enough -- whats your injector duration --should be below 80%

Just dont use any lambda sensors my maper remove them. The injector are 380cc on standart fuel pressure.