Technical t-jet performance

[middo85]

Is this the secret why the S2 T-Jets are faster?

Mine is an 09 S2 T-Jet and it has a VL37, im having the previous owner changed the turbo on Tom's, either that or he's a lucky bugger!!

 

[jameshobiecat]

Surely a bigger turbo isn’t going to give any power advantage without a re-map since the ECU will regulate the boost pressure down to the same level regardless? The only way I can see it helping is if the little standard t-jet turbo can only just reach the threshold boost pressure when operating at its peak. Does anyone know better?

 

[DlightSwitch]

Surely a bigger turbo isn’t going to give any power advantage without a re-map since the ECU will regulate the boost pressure down to the same level regardless? The only way I can see it helping is if the little standard t-jet turbo can only just reach the threshold boost pressure when operating at its peak. Does anyone know better?

You may be right in the case of a bigger turbo, but the VL36/7/8 are all the same size and just internally different. That's all I know unfortunately, because turbo is still new to me

 

[jameshobiecat]

I didn’t mean ‘bigger’ quite so literally, I was talking more in terms of higher flow rate/boost pressure.
Are the Abarth or bravo t-jet turbos variable geometry? That might allow the turbo to reach the maximum allowed pressure more quickly; still wouldn’t increase peak BHP though.

 

[TallTom]

Mine is an 09 S2 T-Jet and it has a VL37, im having the previous owner changed the turbo on Tom's, either that or he's a lucky bugger!!

I was the previous owner, from brand new 4 delivery miles I think. No changes at all apart from some kick plates.

It made 145BHP when I had it RR at Red Dot as standard so his induction kit added just over 1 BHP if the figures are correct.

 

[middo85]

I was the previous owner, from brand new 4 delivery miles I think. No changes at all apart from some kick plates.

It made 145BHP when I had it RR at Red Dot as standard so his induction kit added just over 1 BHP if the figures are correct.

Thats surprising,

Someone cant have been paying attention on the assembly line, or they hadnt had the right delivery that week lol

 

[DlightSwitch]

I was the previous owner, from brand new 4 delivery miles I think. No changes at all apart from some kick plates.

It made 145BHP when I had it RR at Red Dot as standard so his induction kit added just over 1 BHP if the figures are correct.

I know this will cause argument here, but don't people often say that Red Dot's rollers overread by about 10%? So 145*0.9 = 130.5 which is exactly what my T-Jet made standard (not saying my rollers were exact either) But I think the Vl37 should have made more of a difference than that..

 

[Krysten CTR]

Same argument about rolling roads appears and only the manufacturers change.

A rolling road is only as good as the operator. Provided a consistent set of conditions are used each time, then it doesn't matter what the result is on the first runs. It's being able to show the additional power etc above the initial readings that matters on the subsequent runs.

 

[Tom 91]

My RR wasnt at red dot so im not bothered and Tom was is it with you and the 1 or so bhp i gained from the induction kit?!

 

[DlightSwitch]

Same argument about rolling roads appears and only the manufacturers change.

A rolling road is only as good as the operator. Provided a consistent set of conditions are used each time, then it doesn't matter what the result is on the first runs. It's being able to show the additional power etc above the initial readings that matters on the subsequent runs.

Yes I totally agree, you've made a point completelty different to mine, but correct nonetheless. Mine ran 130 standard and 173 after VL36, Forge FMIC, Induction & Catback. Gain of 43 which is about right compared to others who have gone 140-185 roughly at red dot.

So basically the point is, Tom91 needs to get his on the same RR again after his map/mods and see what the gains are to find out what his turbo is like.

The VL37 is meant to be better than the VL38 as far as I know, so it's still entirely possible that it is a VL38 with the wrong part number on it, but we won't know yet..

 

[Vance]

VL37 surely can't be as tuneable as the VL38 if its in a standard 155hp mito?

 

[punto_matt]

Yes I totally agree, you've made a point completelty different to mine, but correct nonetheless. Mine ran 130 standard and 173 after VL36, Forge FMIC, Induction & Catback. Gain of 43 which is about right compared to others who have gone 140-185 roughly at red dot.

So basically the point is, Tom91 needs to get his on the same RR again after his map/mods and see what the gains are to find out what his turbo is like.

The VL37 is meant to be better than the VL38 as far as I know, so it's still entirely possible that it is a VL38 with the wrong part number on it, but we won't know yet..

To get a fair comparison you need to RR before do the mods and then RR again. Atmospheric conditions have a part to play in the readout of a RR. Its all ******** anyway. You need it on an engine dyno to find proper power, or go off the ATW figures instead of calculated fly wheel as any operator can change the % they allow for transmission losses