so ive just blown the t34/63. the engine has ported head, cams, greys, low comp etc and was mapped by kenny@msd a year ago.

given that the universal turbo t38 has the same exhaust etc as the t34/63 and that the main problem with the t34 is running out of puff at high rpm, can i simply fit a UT T38 without remap???

 

NO!

 

What i would expect to happen:


You can fit it and it will run ok, and seem like there isnt a problem.

Then at high rpm it will melt as it will be too lean.



Try it and see mate (providing your engine is completely disposable of course!)

 

"NO"



as i understood from one of stu's excellent essays, the problem with changing a turbo is that the resistance to exhaust gas that the piston has to overcome on exhaust stroke will change affecting the pumping efficiency. since the exhaust is apparently the same then why wont it work? moe than 'NO' would be useful

 

so more fuel enrichmnet at high rpm with high boost would be required?

 

best to get it mapped unless you fancy paying for a new engine

 

Yes, and less timing too


although you would be FAR better off talking to Stu if its him who did your map, as only he can comment on its contents, the rest of us are just going to have to make assumptions.

Did you discuss with him the fact you might be going T38?

In which case he may have populated the map with enough "safety" for that to happen, but it seems unlikely to me.

 

i'd imagine the map you have now will still be fairly close,with just a bit of tweaking mid and top end needed.....which i'm sure Stu/Kenny would sort quite easily and quickly...

what i mean is i doubt very much you'd need an entire remap,so it wouldn't be of great cost to yourself?

 

im in the same situation with mine.. ive put a tt t38 on mine as the old t34 needed replacing and was told to run the new turbo at lower boost until its mapped properly. feels totaly different to drive but trying not to drive it too much in fear of meltdown..

 

i cant see the problem,,, get the MAPPED

 

...tbh i run a collins t34 .63 chip when i put the t38 universal turbos version on like here...i monitered it and it went like stink on greys...and didnt lean out...goes to show how rich some greys chips run!

Never had a problem..but i wouldnt recommend unless you got wideband afr and det cans

 

Phil, also shows how compromised an "off the shelf" chip can be with regards to ultimate power/correct fueling/ecomomy/drivability........especially when compared to a good live mapped car that would have perfect fueling on boost and off boost with just a bit of timing taken out for safety (2 - 3 degrees).

 

i cant see the problem,,, get the MAPPED

well the problem is three fold:

1) i need the car running asap and it will be 3 months before msd can fit it in for mapping

2) since the rest of the motor is fine it would make sense to 'go bigger' now that im forced to buy a turbo anyway

3) im expecting to change to bigger injectors / inlet and t4 / gt35 or something else in new year anyway which will need a further remap and thought the extra oomph of a UT t38 might satisfy me for a bit longer.

could i risk it by turning the fuel pressure up a bit.......

 

never turn the fuel pressure up at all stu will tell you the exact same thing

 

if you read stus write ups you would of read that bigger turbos create more air at the same boost so more air = lean fuel mixture

then theres the ignition would prob nead 4-6 mabey more degree of advance taken out

so either buy a banger to smoke about in or take time out to get it to stus or buy a off the shelf chip from stu

 

appreciate all the replies.

i was thinking that since the exhaust housing was the same then the restiction through the engine would be the same at say 2 bar @ 5k with either t34 or t38, and that the bigger ultimate pumping ability of the t38 would be only relevant at 'unmapped' areas such as 2 bar at 7k? anyway just talked to Ut and they say that the exhaust housing gets machined anyway and they fit a diff turbine wheel so even if my theory was correct the premise was wrong

new t34 it is then, will be for sale in early 2007

 

PGT9

I did the same as you - but ran the turbo at far lower boost while waiting for Karl to map my car.

I have a wide band AFR in the car so I could at least see what the fueling was up to.

HOWEVER - I personally would not recommend it - and suggest either hanging on for Stu, or if you are desperate to get running then ring other tuners if needs be. Personally I used Karl as he has done good work for my brother, loads on here use him, and he had a slightly shorter waiting list.

Having now met the bloke, and since driven the car, the money spent was well worth it. T38's transform the car.... but don't melt your engine --- that's never a good plan!

Si

 

Morning chaps, sorry for the delay, ive been on holiday.

The T38 uses a ported rear end normally so does increase the engine's VE quite a lot which is where a lot of teh gains come from, but also remember this:

A T34 flat out with greys wil normally have a closed or almost closed wastegate at high rpm due to teh fact the engine is consuming more air than it can supply so we are running the compressor at max speed and usually well off its efficiency island.

A T38 will have an open wastegate at this point and as a result will increase the engines VE due to reduced T.I.P and teh fact the compressor is actualy still within a decent efficiency range. Allied to this larger compressor having a greater adiabatic efficiency and producing somewhat cooler air than the T34 did, you are looking at a serious leaning of the fuel mixture at high rpm on a t34 map.

One question always worth asking yourself:

"If it DOESNT make my engine run leaner, should i actually bother fitting it at all?"

Think about that one carefully...

 

the orical of fords has spoken

 

PS: Just for peoples information as it has been mentioned on here twice;

Due to some restructuring of the way we do things and the fact we will now supply grey maps off teh shelf we now have a far shorter mapping wait than we used to have. Nowhere near 3 months.

 

BTTT

 

Cos if it doesn't make it leaner, its not making more air, thereofre wouldn't produce any more power even if you had it re-mapped etc?

 

Top of the class fella...