john banks

Hoppy has a TD04L hybrid turbo. Stephen Done has the same turbo (my previous one) and 311 BHP 308 lbft but with more breathing mods. It is a great turbo for road use - robust, lag free and comes in pretty low. It is only if you are insane that you need more for road use and the area under the torque curve is very impressive It is still quite sympathetic to your internals and transmission. I personally would and did go for a bit bigger - VF28 is a nice all rounder without going silly and a little punchier still. If you spend more you can get a hybrid like an MD304 that spools like a VF28 but flows like a VF22. Speak to Mark Aigin m@rk-a.com about all these turbos. Fuel pump also highly recommended.

[Edited by john banks - 11/3/2002 2:14:12 PM]

RT

John, how does reducing back pressure reduce the possiblity of det? Also, is your listing in a specific order ie you would first reduce boost, then retard timing, then add fuel etc...?

Cheers.

EDIT: I just realised that with the turbocharger in the plumbing downstream of the headers, there's only so much back pressure you can remove, as compared to a NA car. True?

[Edited by RT - 11/4/2002 8:40:09 AM]

^OPM^

jus been reading something about knock link-erm what is it-i have a MY01 with an itg air filter and a TSL group n back box-would erm well u know lol?
can anyone answer in simple english please

Hoppy

Link is a brand of electonic engine gubbins - short for Possum-Link I believe, made in New Zealand. They do ECUs and other stuff.

Knock is a term commonly used to describe pre-detonation, also known as det or pinking.

This condition is common to highly tuned turbo-charged engines, and in extreme circumstances will bend or snap conrods, obviously with terminal consquences.

A KnockLink is a kind of microphone bolted to the engine block, linked to green, orange and red warning lights in a display unit mounted to the dash. It warns you when things are going wrong and you should lift-off - high in-let temps, poor fuel, excessive boost, getting too hot on a track day etc.

If your car is pushing 250bhp or more, you may have problems and a KnockLink will tell you. If it lights up whenever you floor it, you need to adjust your ECU map which should be taylored to match your engine mods.

I have a KnockLink and ECU Tek3 re-map by John Banks. My car has about 310bhp and never a hint of knock

Cheers,

Richard.

Re-Volt

hoppy ... thank you that was really simple english ....

^OPM^

so for future reference how much do these cost and how much does it cost to get ur ECU re-mapped

ak47mh

Hoppy mate, what other mods are you running to make 310BHP - very interested??

Cheers,
Ant

LG John

What turbo have you got hoppy?

ak47mh

Setup I have so far is 99 Turbo with full decat and Tek2 which made 257BHP and 254LBS/FT of torque.

Will probably be getting induction kit next with samco hoses. Have seen Steve Done's car which is very impressive but don't like the idea of a new manifold losing the scooby sound.

If I did go for a VF28 turbo (and TMIC or FMIC) with remap, what power figures could I be looking at running safely?

john banks

300-320 BHP.

Hoppy

John knows more about my car than I do, as most of the goodies came off his! It's taken me a couple of years to get where I am, but my motor is running soooo sweet now

Starting point is a UK00, full decat exhaust, ITG panel filter. Then TDO4L hybrid turbo, Scoobysport equal(ish) length manifold, huge top-mount inter-cooler, and Tek3 custom remap.

The turbo is brilliant (£500 exchange unit from Mark R19KET - bargain). I have lost little or nothing in spool-up, theshhold or lag, but gained loads of middle and top-end. I get 1 bar at 2,700rpm and John has mapped it to hold around 1.3. It could go higher, but if you push it too much you have to back off the ignition and actually lose power. John spent a lot of time finding the sweet-spot for optimum speed and safety.

The ScoobySport manifold frees up the top-end even more and the needle now races past 6,000rpm. These pipes and the hybrid turbo seem like they were made for eachother. John Banks agrees.

The big TMIC (forgot the brand!) rounds off the package and allowed John to push the map a bit more with safety. Mapped for 97 octane and I run it on straight Optimax. Knock is monitored by the KnockLink (£150 from BRD) and if boost goes too high in winter I'll wind out the Dawes MBC which replaces the restrictor. For track days, I'll wind it out a bit more for safety.

The engine now sounds nothing like a Scoob (which is a real shame ) but is super-smooth and driveable. There's gentle power from 2,000rpm and then it just builds and builds. At 3,000rpm you don't just get a push in the seat, it throws your head back

Power figures are John's estimates from his car and others on the rollers - around 300ft/lbs at 3,500 and 310 bhp at 6,400. I'll stick it on a dyno soon but the best thing about it is the way it delivers that power - smooth all the way and from low revs.

The car now has 251 bhp-per-ton. An STi-7 with PPP has 204 bhp-per-ton

Cheers,

Richard.

stevebt

iTrader: (8)

sorry to hijack the thread but how much is a second hand vf28 turbo worth

john banks

£3-400

JamieMacdonald

Another question related to knock. I think I've almost got my head around this but was wondering how the map is changed to eradicate knock (knock correction?). Is the ignition curve changed or is it the amount of fuel injected which is changed? If it's the latter how is this controlled on a car with carbs for example?
One more thing is knock the same as 'pinking' - a term which I used to hear about when I had a Golf 16V and was cured by using a higher octane fuel?

Cheers
J (Who finds modern engines harder to understand than compooters!)

john banks

Reduce boost, retard timing, add fuel, increase octane, improve intercooling, reduce backpressure.

LG John

Very nice hoppy, sounds like a sweetie. My only complaint would be the up-pipe. Heard it on JB's car at knockhill and the burble was gone

Hoppy

Saxo, it isn't the up-pipe that loses the Scooby-throb, but the almost-equal-length ScoobySport manifold piping. Probably deliberately enhanced by Subaru in their choice of iron (not steel) for the pipes in the OEM manifold.

John Banks and I share mods with Floyd and he is a bit of a star when it comes to spanners and electrics. Amongst other things, Floyd has done a fabulous job porting my OEM manifold so it should be (almost) as good as my ScoobySport jobbie. I guess I'll bung it back on some time, though it's a pig of a job. The car will be a bit slower top end, but I didn't realise how much that deep off-beat sound meant to me. Sad b@stard that I am.

My daughter compains that my car doesn't sound so hunky when I pick her up from the school disco Which does nothing for my mid-life crisis

Cheers,

Richard.

john banks

Bigger turbo running the same airflow will have less backpressure and more airflow.

If you have restricted gas exit from the cylinders you increase the likelihood of detonation. So free breathing exhaust and big turbo help with reducing detonation for the same airflow.

JamieMacdonald

So does that mean my car is less likely to knock since having a full decat? Cool
From what you're saying John would a standard car be more prone to knock than a modified car (running stndard boost), as a modified car should breathe better in theory?

Jamie

john banks

You are looking at it a bit one dimensionally. Read Maximum Boost by Corky Bell.

annointed

KnockLink is a nice tool, and probably worth having in most modd'd Scooby's. I have two Knock read-outs displayed in my car, but one is on my Power FC, which is mounted down by the ebrake. Since I can't watch down there when I'm ripping around, I decided to get a KnockLink, and install it up by my gauges, where I can see the LED's shouting at me when/if detonation is occurring.

Based on the two systems, each reading of different sensors, the KnockLink is surprisingly in synch with the stock sensor that the computer sees, although they still each see differntly on some things. My knocklink lights up every time I hit my power door lock button, but the PFC doesn't even blip.

JamieMacdonald

I think you're right John - I guess a trip to the library is needed. It would be nice to know what is going on in that noisy metal box under my bonnet