just a quick question turbos

**maceastern** · Saturday 13th June 2009, 03:31

hi ive owned a few t5s in the past but ive just bought a c70 with the lpt i was wandering if it was possible to fit the hpt off the t5 to the 2.5 lpt engine would it cause any damage etc thanks alot mac

**p fandango** · Saturday 13th June 2009, 07:33

i'm sure it has been done, you wouldn't be able to get the full beneift out of it as the boost would have to be set at a lower pressure to the T-5 because of the compression ratios & your engine not being built for it

i'd wait for some verification from someone who's done it first

**mk3phill** · Saturday 13th June 2009, 12:08

it is possible. despite the ready available-ness of T5 motors im working on a lpt also. you can fit the turbo.. you can do as much to this engine as a T5 the only differences are as a stock engine on runs high boost an the other low. bottom ends with exception to the bores are identical from my own findings, months of research and use of vadis. although if you want to reap the full benifits then id suggest a remap to go with it.

only situaton here is depending on how far you want to go with the car. if you just want a bit more power but not too worried about fuleing then a MBC can be had cheap with gains,. bomb192uk has done this to his 850 awd so maybe speak to him also

**p fandango** · Saturday 13th June 2009, 13:10

Originally Posted by mk3phill

it is possible. despite the ready available-ness of T5 motors im working on a lpt also. you can fit the turbo.. you can do as much to this engine as a T5 the only differences are as a stock engine on runs high boost an the other low. bottom ends with exception to the bores are identical from my own findings, months of research and use of vadis. although if you want to reap the full benifits then id suggest a remap to go with it.

the lpt also has a compression ratio of 10.5:1 while the T-5 has a ratio of 8.5:1

**AlanG** · Saturday 13th June 2009, 16:48

Sounds risky. 10.5 and an hpt is a timebomb. Just buy a T5,they are 2 for a pound just now.

**mk3phill** · Saturday 13th June 2009, 19:14

sorry to correct but the lpt runs at 9.0:1 yes higher than a T5 but not too much to cause mega problems

**p fandango** · Saturday 13th June 2009, 19:31

Originally Posted by mk3phill

sorry to correct but the lpt runs at 9.0:1 yes higher than a T5 but not too much to cause mega problems

my mistake, i assumed the AWD used the normal 2.5lpt found in FWD 850's but its actually got a special engine for itself

**mk3phill** · Saturday 13th June 2009, 19:43

well im unaware there are two 2.5L lpt's but as far as the B5254T is concerned,.. as used in the awd 850 and s,c,v series heres the tech straight from vadis!

with a comparrision to a B5234T:

**p fandango** · Saturday 13th June 2009, 23:00

Originally Posted by mk3phill

well im unaware there are two 2.5L lpt's but as far as the B5254T is concerned,.. as used in the awd 850 and s,c,v series heres the tech straight from vadis!

with a comparrision to a B5234T:

no as i say i was looking at the FWD version which had a compression ratio of 10.5:1 & had a different spec then listed for the AWD, i haven't got the file on this computer but i'll post up the info (if i remember) once i'm back

**maceastern** · Sunday 14th June 2009, 00:01

hi thanks for all the replies so if i leave the turbo standard does anyone have any idea what sort of bhp i could obtain with a remap thanks the engine is very good only 122000mls manual box the car is quick but not in the same class as the t5

**Dangerous Dave** · Sunday 14th June 2009, 00:49

You're thinking of the B5254S engine PF, it was just a 2.5 NA.

Mac, remaps are quoted to increase bhp up to around 230-235.

I fitted an MBC to mine, and am running around 10psi (standard for LPT is around 5-6psi) and so far I have had no problems. The only thiong I've found is that the car seems slower now than when I first fitted the MBC, and at the moment I'm putting it down to the ecu learning and adapting. I've hit the boost cut a couple of times, so have turned it down a touch.

I am going to take the turbo off and rebuild it soon (got a rebuild kit) once I get some time to myself. And I've got a lot of crap in the intake piping from the damned PCV system, so have got new bits for that to fit soo.

**mk3phill** · Sunday 14th June 2009, 03:19

Originally Posted by p fandango

no as i say i was looking at the FWD version which had a compression ratio of 10.5:1 & had a different spec then listed for the AWD, i haven't got the file on this computer but i'll post up the info (if i remember) once i'm back

ahh right umm well i shall have to agree on bomb with that one as far as the 850 we concerned there was only the T5/R turbo models an the the AWD used the 2.5lpt there was no fwd 850 that came with a 2.5L turbo..well not factory fitted(coughminecough) haha. and as far as i know,. the s,c,v P1 series 2.5lpt is the same as used in 850 awd the B5254T.
That is untill the P2 chassi came alone in which there are numerous of turbo engines from 2.0 2.3 2.4 2.5L

**p fandango** · Sunday 14th June 2009, 08:40

hmm sorry chaps you could be right about the NA bit thinking about it (must learn to look at model numbers lol), but as i say once i'm home i'll have a look at the press release with the model specs on & check

**p fandango** · Sunday 14th June 2009, 16:56

just gone & had a read thru my info & i do believe your right chaps sorry

all the PDF says for the 2.5 FWD is 170bhp but doesn't give a engine number or whether its turbo or not (i just assumed it was), thats pretty good power figure for an NA.

**Dangerous Dave** · Sunday 14th June 2009, 20:00

Yeah, the 2.5 NA 20 valve was 170bhp (the 10 valve was 144bhp)

**p fandango** · Sunday 14th June 2009, 21:01

Originally Posted by bomb192uk

Yeah, the 2.5 NA 20 valve was 170bhp (the 10 valve was 144bhp)

i remember the old Astra MkII GTE's being called "rapid" with 150bhp from a 2.0NA, mind you i bet they don't weigh anything as near as much as an 850 lol

**maceastern** · Monday 15th June 2009, 01:21

ive just purchased a t18 turbo off a v70r im going to give it a try ill update this when its completed thanks for all the help ill let you all know what happens thanks mac

**Enigma666** · Monday 15th June 2009, 09:14

From experience (granted of a 2.0T S40) upgrading the turbo that far is going to end in tears mate

It's not just the compression ratio...the pistons, rods etc from the lpt versions just don't seem to be up to the job, too much Torque and say bye bye to your block.

Just be careful bud

and good luck with it

**maceastern** · Monday 15th June 2009, 09:52

i think your right im goint to try a t15 instead ive asked a guy selling this 330337423946 on ebay and hes gave me a bit info his seems to be running ok could someone have a look and see what they think its the same engine as my c70 thanks mac

**timbo_1975** · Monday 15th June 2009, 10:15

Erm, it isnt clear if you are going to be swapping to a T5 or retaining the stock LPT ECU with your turbo swap?

I am not quite certain where the stock LPT ECU is mapped to, but am certain it is not more than 14psi where the stock fuel cut off operates. I would imagine the stock injectors would be at their max flow by then, so you will need to change to T5 injectors, and thence need a T5 ecu to control them...

If you are able to correctly swap to a T5 ecu, make absolutely totally utterly sure you do not allow the engine more than about 9-10psi under ~3000rpm else you will bend the rods, if not suffer from cronic detonation.

I have a feeling that the only way to make it run properly right without lunching itself would be a programmable ECU and several hours setup on a dyno. At the very least I would be using an active boost controller to manage boost levels vs revs...

Regards, Tim.