Before you start, Yes I know I should ask my tuner, But I'm after everyones opinion, and at the moment I'm on the other side of the world.

Just thought it might be a good topic.

Forget Anti Lag though.............. Not intrested in all that popping and banging.

1. Looking at possibly converting it to roller bearing (If some is capable of doing this.

2. Replacing Exhaust Housing to something like a .55 (If this can be done)

3. And of course cam combinations.

Oh yes, and I'm bored to death over here in Alaska, haven't seen a decent car worth mentioning. Bored, Bored, Bored. But it pays for the Cossie mods.

All on a standard comp engine, Grey Injectors, Modified Head ???

Not after an argument, just some options.

I know Karl has his way of obtaining this, but I thought it might be a good topic and bring out some new ideas. (If your willing to share them of course).

 

Get a GT series turbo if your budget allows

You still coming to Seattle one of these days ?

 

Jim you bored mate, you have all those rich holiday makers to play with,

opps just remembered you have a misses


Mike

 

Jim,

Some suggestions that may help:

1. NOS - use the NOS as a lag suppressent low down in the rev range only.

2. Roller bearing version of a T4........or better still, use the equivelent GT series turbo with up-to-date comperssor wheel/housing design.

3. Greddy (or similar) active boost control.

4. Totaly spec the * WHOLE engine build for LOW LAG, i.e. high compression (eg 8.2:1 comp ratio or higher), AND use a combination of 1, 2, and 3 above

* A very well known and respected Jap car tuner (in the UK) has a YB engine on his dyno THIS WEEK that is based in this thinking!

We will all know the results soon as it will be fitted back in the car within a week or so

 

the right cams will help massively, im sure karl will point you in the right direction

 

Jim,
A roller bearing core will make no difference what-so-ever on spool-up time on your turbo. To get this reduced, you would need to switch to a more modern desing turbo OR have the cams / head / c/r matched to suit.

Harvey does a 425bhp conversion on 4x403s - I'll dig out the dyno-sheet for you to see when the boost can be obtained on a correctly specced car.

 

It goes engine speed / torque / bhp / psi
3000 168.4 96.7 05
3500 229.4 152.7 10
4000 366.5 278.1 23
4500 385.2 329.6 25
5000 378.4 360.5 25
5500 363.5 380.2 25
6000 354.8 404.8 26
6500 346.9 426.8 27
7000 319.6 424.1 27

COMPLETELY standard engine (head, cams, valves etc) with just compression dropped by an "unspecified " amount.

 

change it in for a .63 housing t34

 

Surely a compression drop would make things worse from a lag point of view for Jim wouldn't it? Or are you eluding to the fact Jim is using BD10's & this car being on std cams would make the difference? (assuming Jim's is worse than that).

 

So Karls recommendation is a pile of shit then

T4 sucks the big one...you gotta go to a T34 mate or hi comp and anti lag with the T4

 

mike, does a dyno plot tell you anything about how fast the turbo spools up? or does it just tell you that it's making good boost by 4000 rpm? aren't the transient conditions on the road different to on the dyno (particularly in different gears)?

 

Not necessarily no..

 

Ian,
Jim has standard cams and BD10s would make his lag situation worse.

Phil,
Jim thinks he has a modified exhaust housing, which will effect lag - so nothing to do with Karl .

FRS,
You can replicate the dyno to a certain degree by loading the car up in fifth. This puts the highest load on the turbo and will show you what boost it makes at what revs and is as close you can get to the loads the dyno can achieve.

Jim,
Harvey could do you a special turbo using the front of your T4 and the rear of a GT28, it makes the following (again lowered compression, polished head only (not ported) and one of Harvey's inlet cams):
Revs / torque / bhp / boost
3000 293.4 169.0 24
3500 341.7 230.6 27
4000 340.3 261.4 27
4500 341.6 294.9 27
5000 353.5 336.1 28
5500 354.2 371.8 28
6000 351.0 401.8 27
6500 337.5 418.4 27
7000 320.6 427.9 27
7500 280.5 402.7 27

 

Ian,
Jim has standard cams and BD10s would make his lag situation worse.

Phil,
Jim thinks he has a modified exhaust housing, which will effect lag - so nothing to do with Karl .

FRS,
You can replicate the dyno to a certain degree by loading the car up in fifth. This puts the highest load on the turbo and will show you what boost it makes at what revs and is as close you can get to the loads the dyno can achieve.

Jim,
Harvey could do you a special turbo using the front of your T4 and the rear of a GT28, it makes the following (again lowered compression, polished head only (not ported) and one of Harvey's inlet cams):
Revs / torque / bhp / boost
3000 293.4 169.0 24
3500 341.7 230.6 27
4000 340.3 261.4 27
4500 341.6 294.9 27
5000 353.5 336.1 28
5500 354.2 371.8 28
6000 351.0 401.8 27
6500 337.5 418.4 27
7000 320.6 427.9 27
7500 280.5 402.7 27

 

surely in fifth the turbo is more likely to spool up quicker than it would in the lower gears as you will be using more throttle and it will have time to spool up properly. so those figures are not necessarily representative of the boost that you would see at those engine speeds in gears 1 and 2?

 

Mike...thinks is NOT fact

My car hit full boost at 4.5k....is Jims worse than that then?

T4 = lag and lots of it......why go T4 and 360bhp is beyond me unless you have an ambition to hit the turbos potential

 

You sure? I'm almost positive I remember him fitting BD10's?

 

throw the fooker away put it back on the DAF it came off

 

and it wouldnt make it worse with the right cam timing

 

FRS,
That is 100% correct. I'm just trying to show you how to replicate what the dyno produces to make a comparison. If your car makes less boost than this, then you know that it is going to feel more laggy on the road as this car, or if it matches this, then you know that it is as good as you'll get it with that turbo...

 

Ima,

you dont actually know Jim's spec, so you're just shit stirring again.

Karl wouldnt offer this conversion if it was "shit". Karl and Jim will both know the reason's behind the issue, so

Next you'll be saying that the stage 1 conversion he offers is shit, even tho mine and many other cars testify to show it isnt!

 

Ian / Gareth,
That is straight from the horses mouth about the cams and Jim informed me that Karl agreed that the BD10s would have made things even worse in this set-up than the standard cams....

 

Just done a search & found he decided against BD10's in the end, so yes you are correct Mike & I was wrong

 

looks like i may of been wrong aswell then

 

I said that the other day on a almost identical post, and nobody took any fookin notice.

Being rollerbearing means fuck all.

RS500 style T4s are laggy and shit (relativley compared to newer turbos anyhow) cause they old technology bollocks.

Modern turbos of the same sorta size/powerhandling are far less laggy.

And its feck all to do with roller bastid bearings

Id much rather have a T4 than a T34 tho...

 

Ima,

A T4 on a std engine is my FAVORITE conversion. It simply is awesome for the money involved. I have done a few cars on this conversion and all have been nothing less than breathtaking. There's even a couple of users from this BB that have this setup, and are extremely pleased with the conversion.

Jim's however had some unusual characteristics that I have not been able to pin point. Allthough the turbo starts to make boost quite early, the car does not produce torque until considerably higher up the rev range. It feels for all intents and purposes like it has massively wild cams. It in fact has standard cams timed in correctly.

Since the only difference from his old T34 setup is the turbo, then this surely points to the turbo spec being wrong. Allthough I usually supply the T4 for these conversions, Jim allready had a T4 available to him, allthough of an unknown specification, and it is this that I suspect is causing the lack of torque.


Jim, my advice is to send the turbo for inspection as we discussed. Once we know what exactly you have we can make a decision from there!!

 

You can get the same BHP as Jims by bunging on a T34 .63 on a std engine......are you saying the T4 car has less lag???The T34 may run out of puff quicker but thats good for reliability..as the T4 just wont stop producing!

 

As for the Gunship conversion...imo they are pushing the old injectors too far,i really hope none of your cars experience a melt down.

Its great to see 300 plus from std injectors etc But i would equal it to me making love to 10 women in 10 hrs...can be done...but i bet it would kill me...ROFL.

 

what's that got to do with anything?

 

Ima,

The T4 conversion on the standard engine normally makes a genuine 370bhp. With cams that rises to 400bhp.

I have found that when using a 0.63 T34 on a standard engine will just about give 350bhp, put the power tails massively after around 6500, whereas the T4 equiped engine will pull to 7500pm.

in addition the T34 is being pushed quite hard to make 350bhp where as a T4 is positively laughing at anything up to 400bhp!

I like revvy engines and the purpose of this conversion is to make plenty of top end power for minimal budget!

 

 

But as you see here Jim hates the lag!...and even with a correct T4 it would still be bad.It really interests me that you can make no more than 350 from a .63 But 300plus on a totally std engine

FRS Sapphy brought it up!

 

Ok.. Just before I get my coat....

A small compressed air bottle, mounted close to the zorst manifold.. Stick with me..

Fit a recirculating DV and route the vented boost to the bottle, via a one way valve.. This way you will keep the pressure, BUT as the bottle is loads hotter than the charged air, it will expand and increase in pressure..
Then when the throttle is re-applied, with a pressure activated switch in the manifold, release the pressurized air back into the compressor side of the turbo... WHOOOSH.. and you're off...

Either that or just carry a bottle of compressed O2 and squirt it over the blades when neccessary..

Yeah... I'm bored too... :blonde:


Luv
Chrisie...

 

why not make excess boost by keeping the wastegate closed, but bleed off the excess boost into a receiver that can then be dumped back into the inlet when boost is reqired but the turbo hasn't started making it yet?

i believe that was what ford did with the wrc focus but was outlawed soon afterwards?

 

I did see something about that!

Big container in the boot, that stayed constantly pressurised - a very effective form of anti-lag!

 

Ima,

The T34 IS a T3 derivative!!!! The exhaust wheel is identical to the std turbo and hence why when fitted with a 0.48 exhaust housing a T34 is very similar to the std turbo. The only difference a T34 has is a slightly larger compressor wheel and the larger A/R 60 compressor housing. This essentially makes the T34 60bhp potential up on standard.

I.E a std turbo will sit at 300bhp as its reliable limit where as a T34 is at 360bhp. (320bhp for the 60 trim 4X4 T3)

Even with a 0.63 exhaust housing the exhaust wheel is just as restrictive and why a T34 is not even in the same ball park as the T4.

Don't get me wrong I like the T34, its a fantastic little turbo, but they simply don't have the flow potential to give you increasing power all the way to the limiter like a T4!

 

Oih... I just said that...

Didn't realise it had been tried tho... Clever little me for just thinking it up..


Luv
Chrisie...

 

Hey Karl,

What about a T-38. It's nice between the t-34 and the T-4. Do you have experience with this one. I've heard a T-38 has a .63 ex house. But this turbi has the potential for 460bhp.

Best regards,

wim van der werf

 

Ive mapped a couple of T38 motors and its a good turbo "IF" its matched with a correctly specced engine.

It is NOT great on a standard spec head and compression ratio lump due to its large compressor map as it will surge like hell, but then, so will a T4.... lol.

Another great alternative is the MD240R, but surge again is an issue.

 

Sorry Jim,
I havent commented on your question as it seems all that needs to be said, has been said already.