Andy,

"I know for a fact that if my engine is set to run with optimum timing and boost for a rolling road run at Star performance (read slow ramp rate) it does not perform as well on the 1/4 (fast ramp rate) as it does with more timing, less fuel and more boost."

Hmmm, but what's tuning a car for a "rolling road run" got to do with tuning on an "engine dyno" ?

You have no control over engine temps, the way load is applied on a RR is rarely representative of how a car is loaded on the "road", let alone consistant. How common is it to see your max boost/torque achieved far later on a RR, than is seen in reality on the road.

All you're doing on an engine dyno, is mapping each "load" zone to the AFR you decide you want to run, and advancing the ignition to either MBT, or to just before the engine starts to det'.

I agree that a car tuned on the dyno, can still be tweeked, and improved on the road, but that's more about tweeking to match the whole exhaust system, and better flow to the IC.

But that's not what you're talking about,

"I can safely run more boost, more timing and weaker fuel for the 11. odd seconds it takes to run a 1/4m than I would run on a track day for example."

Sure, I ran 40psi(2.76bar) on the engine dyno, for about 10 seconds, with no det', and I guess I could run a 1/4 that way too, but I wouldn't run it on a track day either.

Mark.




[Edited by R19KET - 5/3/2003 2:38:54 AM]

It would melt the pistons and knock out the big ends whilst making less power.

However, if I added 20% fuel and retarded 5 degrees.......
0.1 bar boost would more than compensate :)

[Edited by Andy.F - 5/3/2003 7:48:56 PM]

Is any one running one of Lateral Performances hybrids turbos? Spoke to Mark today and seem quite tempting to go for what I think was a VF turbo with garrett internals. Would be most gratefull if I could get some info of people which are using his turbos?!!?
Thanks

There is a guy in Scotland called Alan G. who has had several, so he will be able to give you a good opinion. I will get you his e.mail tomorrow or you could post on here for him.

As always there is a juggling act between various areas of the RPM range for high specific outputs.

I suggest if you want to learn the subject for yourself getting yourself a copy of Maximum Boost by Corky Bell and read it before making your decision. Aside from a few minor inaccuracies this book is widely considered to be a classic and well rounded text on the subject of turbocharging.

If you don't want to do that then at least bull yourself up on most of the following topics:

Exhaust back pressure
Detonation
Compressor efficiency
Compressor surge
AR ratio
Compressor map
Volumetric efficiency
Intercooling
Fuel supply
Oils
Wastegate
Boost control techniques

or alternatively copy someone else's entire setup that has the results and driveability that appeal to you.

Weenie

Unless you are going for well over 400bhp then you don't need anything as special as a Garrett core IMO. Any of the Garrett core /VF hybrids that I have seen on Subaru's have done 'nothing' under 4000rpm :eek:

Don't make the mistake of over sizing the turbo, I'd suggest you get one that's 'just' big enough for your application.

What are your power aims ? People may be able to suggest suitable units from their experience :)

Andy

Harvey,

Let me save you the trouble. Alan Garrod's email is mines@scoobyturbo.freeserve.co.uk

I agree with Andy about not over sizing the turbo.

My initial suggestion, was a front entry TD05, but Ed doesn't really want to run the boost on his UK car, that would most likely be needed for 360bhp (his target power).

I think the TD06 would also be an option, but not with the 20G wheel.

My recommendation, was for Ed to wait a couple of weeks, and see what develops ;)

So, what would the Scottish mafia suggest for 360bhp, running a max of 1.3~1.4bar ? :D

Mark.

Bbbaaaaaaahhhhhhhhhhhhhhhhhhh. Like lambs.

Stay with conventional thinking when a top power Scooby was 360-380bhp or waken up to the genuine power available to you for very little effort.

"My recommendation, was for Ed to wait a couple of weeks, and see what develops"

Who is doing your development work ?.

About time you started getting turbos that work and were able to map cars with or without Pats assistance that had to go back to Bob Rawle to be sorted out.

I cannot remember whether it was on Murrays profile or Anders but I think its appropriate.

and I am not even in the Scottish maffia . Yet!!!
I do think all the bull **** on S/Net should be exposed.

Harvey,

I'm not going to lower myself, and get into a slanging match with you. You're entitled to post whatever you want, but it would be nice if what you stated, or infered, was accurate !

Since I can only assume that your "mapping comments" are related to Alan Garrods car, I would suggest that you ask him exactly what happened, and why.

"I do think all the bull **** on S/Net should be exposed."

I agree.

Andy,

IIRC, the main problem with the TD06 conversion, is that below 4000rpm, it's surging, even at 1.2bar. Have you managed to solve the problem then. It's not the impression John B gave me earlier this week.

Personally, I think the TD06 cover, but with an alternative wheel could work very well. Like you've said,

" Don't make the mistake of over sizing the turbo, I'd suggest you get one that's 'just' big enough for your application."

Mark.

Mark

As you are aware, no 2 cars respond exactly the same. My stage 1 boost is 1.3 bar, my car achieves this from 3000rpm onwards with no surge whatsoever. I can switch to stage 2 boost and run up to 2 bar anywhere after 4500rpm.
JB's figures are slightly different (1.2 and 4800 IIRC) or maybe it's our rpm/boost gauges !
Ideally it would be a gradual ramp up in pressure but I've yet to find a boost controller that can do this similarly in each gear.

As far as I'm aware there is no other turbo that can run 1 bar by 2800rpm, match a TD04 or TD05 for bottom end torque and continue on to give circa 450bhp at the top end on a 2.0 scoob.

I hope you can publish the results of your development tests :)

Andy

Andy,

I'll let you know the results.

Mark.

Big Brother ;) :)

Another big brother;)

We thought Andy's shorter gearing meant that he only had a surge issue in his top gear, mine has an issue in the top 2 gears (4th = his 5th). The time you are in the zone and the amount of load seems to encourage the surge.

In 3rd gear I can run pretty much what the exhaust side will spool up. In 4th and 5th I have to keep the boost to about 1.3 bar until about 4500 RPM after which you can let rip.

What it would be nice to find is a wheel which has a more leftward surge line than the 20g but will still flow the same or more. I've looked at all the maps available for the Garrett T04 wheels and can't find one to do the job. The GT30 (?) wheel map that was shown is slightly phatter at the top though with similar area for the surge line.

If you use a larger turbine you then can lose the bottom end. It is a waste of top end exhaust gas back pressure if you had to really hold back a turbo in every gear to stop it surging IMHO, but also a shame if you size so big that you lose so much bottom end. I think we are attempting pretty big specific power outputs from a single turbo and with present technology it is difficult especially with our long manifolds.

With the right boost control the 20G TD05/06 hybrid is great, but it really needs that. If something can be worked out with a larger area under the curve that would be great, but with present technology and lack of Garrett GT compressor maps available to us it is tricky.

Big brother's Little Brother, Pop world.... why did this turn into a thread listing some of T4's ****ty TV programmes????? As for that bloody Vernon Kay :rolleyes: .

Tony.

Weenie, I was running a BT270/MD304 or whatever they are called now!!! :D Sorry Mark. ;)

This was using a homemade skylined cored intercooler. Results = 1 BAR boost by 2700 RPM, then able to make 1.6/7 BAR to the redline. I think I was one of the first people to play with these turbo's with Mark, and we was both VERY happy with the results.

Dan

PS. This kit is now up for sale. ;)

I can highly recommend Lateral Performance.

Mark :It is because Alan has told me exactly what led him to go to Bob's with you and because Alan has tried out several of your incarnations that it would be prudent for Weenie to drop an e-mail to Alan.

I've bought a hybrid turbo from Lateral Performance, and I'm more than happy with the results. :)

I've got a LATERAL PERFORMANCE IHI/GARRETT hybrid turbo,i can honestly say i'm very happy with this product,my car is a lot sronger at the top end over the vf22 that was on before,the last rolling road session at PE it ran 375bhp 324 lbs/ft torque at 1.4 bar of boost.it holds 1.6 bar on the road,Also mark has been very good and fair to me with the purchases i've had,including clutch,flywheel,fuel pump and fuel regulater,would recommend LATERAL PERFORMANCE to any of my friends.Alan Mcrae...

Alan,

Nice result.. what ecu do you use??

You a lurker?? Seems to me theres more high powered cars about than I thought :(

David,

you don't know big AL?

His car was on a link, but is now motec'd, you would have to speak to pat and mark about the mapping.

I can say that I am friends with mark, and met him through the cars, not independently.

He has always given me impartial advice and like others on this thread has on two occasions convinced me not to buy something from him.

I have had two IHI hybrids from him which I was also very pleased with, I swapped because I decided I wanted massive low down torque and grew bored with the top end flow of my previous hybrid.

He has also helped me collate the parts needed for my engine build and put me in touch with the right people, so that I have as much confidence as possible in the strength of the engine (a subjective term when pushing the limits).

I can also vouch for his integrity and would happily continue to recommend him to anyone seeking balanced advice.

edited cos I got garrett and IHI confused!

[Edited by Adam M - 4/9/2003 3:24:25 PM]

Nope.. :confused:

Must add: I have a Lateral Performance Turbo, and we hope to be very happy together.. :)

David

What does L/T mean Steve?

Like Adam I met Mark through subarus and fettling them, his advice has always been heeded, and I've bought many pieces through him including what I still regard as quite possibly the best matched hybrid for a standard internal engined UK car, the MD304...

It's perfect for what I want, looses nothing to the TD04 at the low end...and keeps on going when it's mapped properly...

Part of me wants to build an engine just to find out what this Turbo can do...the other part of me wants to spend all my hard earned with Mark to build a monster ;)

Tim

There are a few that would disagree with you on the MD304 matching the TD04 bottom end :confused:

Do you have dyno graphs to back up your claim ?

ooops, yes that will be L/P then... if i had half a brain...:) steve standing corrected.
:)

Would that be Turbo Dynamics then ;)