Hello

Just interested to know what ballpark timing you are all running at boost.

So far I have mapped up to 1.4-1.5 bar boost, and I am running 16 degrees of advance there.

I'm running 23 degrees at 1 bar.

I am hearing NO knock either through my knock block, or my traditional copper pipe/hosepipe/ear defenders knock detection 'system'

I get the occasional spike on my knock link, and on my GM knock sensor in the block (Up to around 3.8V) but I believe this to be engine noise as I cannot hear any real det.

I'm mapping on UK RON 97 BP ultimate.

Upped the timing a bit more, no audible knock as yet, but loads more go!!

Running out of spark at 1.4/5 bar - need to gap the plugs down slightly.

It has to be said, the GT35 is laggy as hell, but once it spins up, it's ridiculous.

Hi Mark,

I'm on a GenII with a hybrid CT20b at 1.4bar (off road testing of course)

Here's my ign map

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This is an AFR log (extrapolated from Lambda)

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And the co-inciding knock log

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Note that I am on e85, which reduces the knock dramatically. It used to be much higher previously (i.e. up to 50 and 60 :ohmy: )

I'm going to the dyno on Saturday morning so we'll see what it outputs. I have no idea what A/R my turbo is.

What A/R is your GT35? do you have a boost chart available? big turbo you've got there :)

What are the units up the side in your map? My units are in kPa

This is roughly what I have arrived at so far - there is a lot more advance to go yet, as I am not hearing anything in the knock block, or getting any mad voltage spikes on the knock traces from the ECU logs.

The a/r on the turbo is 0.82 I believe.


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I think it's kg/m²

If you are full on the throttle is it using the cells in the top two lines? they look a little low. Having said that I read that it's best to pick your target boost and build up your timing once you're happy with it, and having more boost and less timing is better than more timing and less boost.

I read somewhere that a gt3582 is only waking up at 20psi and can run 25-30 all day. Are you taking this sucker to Enniskillen?

I'm not using the top rows at all yet - I have fuel cut set at 280 kPa/1.8 bar.

I only have the boost control allowing it to go to 1.5 bar so far as well - havent gone any higher yet.

It definitely is extremely laggy, I can set a 2-step/launch control pretty easily with one click though for a good launch. But I'm sure I wont be doing too many of those!

It certainly only starts to come on song over 1 bar - starts making an almighty racket!

When I finish mapping it I might take it to a strip just to see how it goes.

Sounds awesome! hope to get to see it one day

Keep posting up your progress too, it makes interesting reading

Gapped the plugs down to 0.025'', seems to have cured some stuttering at 1.5/1.6 bar - but I fear I am going to have to run individual coil packs, or an MSD ignition box.

Definitely running out of spark.

3rd and 4th gears are great! Am glad I rebuilt the gearbox the last time I had the engine out now.

Was having a bad misfire at high revs - set the dwell to be 3ms across the rev range and it seems to have cured that.

Next step is coil on plug ignition.

wow sounds great

Regarding the lag, I seem to remember reading somewhere that this can be reduced by retarding pre-spool ignition timing. Might be just my imagination but thought I would pass that on if it's any use.

What capacity is your engine 2.0 or have you gone to 2.2?

I have a slight dip in timing before boost starts to come on, but the Gt35 is a laggy bastard.

I've a 2.0 sleeved block - didn't see the point in 2.2 TBH - I've kept everything as small as possible - 86mm pistons.

Well they say that higher capacity will make the turbo spool faster. On the other hand people also say that over square is much better for drag racing and stroking an engine is the wrong approach. On the other other hand ATS have the top 5 cars on the MR2OC.com dyno shootout, all of them making huge power on 2.2's at the top end where you want it for drag racing. So I don't know...

Is the century MR2 not 2.0 ?

It's all swings and roundabouts!

From my own experience, a couple of 100 cc's isn't a lot - unless it's a highly strung n/a.

true, but it's supposed to be better to bore than stroke for high RPM motors

Got fed up with the boost control on the AEM, so put another spring in my wastegate.

Spring pressure is now 1.4 bar

Not seeing any red lights on the knock link now (And cant hear anything much on the knock block), and the AEM is hardly retarding the timing with knock at all, so I must be getting somewhere.

The acceleration over 5000RPM is brutal.

mark239 wrote:


The acceleration over 5000RPM is brutal.

Let's see a dyno chart

But remember: valve bounce can be brutal too


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I've done that before, on an Mi16 at almost 9000RPM!

I used to have a Yamaha FZR250rr. It was a 250cc 4 stroke, 16 valve with a factory redline at 16,500rpm. I wonder how they ever did that? maybe because the valves were so small (pinky sized) and maybe they went less distance?

Those engines have a really short stroke for starters - and the valvetrain is super light. The cams are gear driven too.

Those FZRs were futuristic at the time. I'd have gone for a ZX-2R if I hadnt been a 2-stroke fiend, and had a couple of RD350 YPVS's and an RG500 square 4.

Some bikes have special valve trains as well. You definitely see the best N/A tech on bike engines, that's for sure. My brother is a bike mechanic and some of the stuff that is in even older units (late 1980s) is way ahead of cars.

They had an NR750 in his work recently - oval pistons!

Yes I've seen pics of the oval pistons before - also one that has two rods to one piston

One time I saw an FZR250rr engine stripped to parts, it was really like a small little model compared to a car engine - amazing. I rode an RGV250 once and that was enough. Not sure I could handle an RG500!

Biggest (and newest) bike I got a turn on was a neighbors Triumph T595. 1000cc with EFI. It was truly amazing in every respect.

Have just ordered a set of LS2 coils from the states, so hopefully going individual coil packs in a few days.

LS2 coils have the igniters built in, so I just use 4 of the 10 ignition outputs on the AEM to drive them.

nice!

Any pics?

It's these ones here

[url=http://cgi.ebay.com/ebaymotors/GM-LS2-high-output-coil-far-superior-than-LS1- coil_W0QQcmdZViewItemQQhashZitem1c092b8b59QQitemZ120412932953QQptZMotorsQ5fCarQ5fTruc kQ5fPartsQ5fAccessories#ht_702wt_939[/url]

I should be able to drive them from the AEM, as I have loads of spare coil drivers.

Built in igniters - can't be bad for 25 odd quid each.

Need to source ECU plug pins from somewhere (If anyone can help there) and make some short plug leads.

Will be leaving the distributor in place.

cool

can't wait to see how this pans out!