Some HP questions

[Roy]

So what i need to know is will an ECU like Wolf 3D Ver4 be able to run an engine with 272 cams properly. Not knowing the sort of idle or lumpiness of this cam im not sure if the MAP sensor will be upset by the fluctuating inlet pressures, meaning a high idle. Or should i stick with OE ECU if i want to maintain reasonalve idle quality?

Also does anyone have these cams fitted to their RB20, does the increase in lift require machining of the head. Im looking at using these cams in conjunction with a mild tidy up of the heads and adjustable cam gears (HKS gear looks to be about the cheapest).

Generically speaking what do these cams do to the power/torque curve, make it peakier (i think) or a broader power range (as HKS catalogue claims)

[meggala]

roy personally I think 272 cams are to big for an rb 20 I think there isa much broader range of pwoer in using the 256-260 cam.s for anrb 25 or 26 the 272 arent any where near as bad teh rb 20 you hear me refer to that made 550-600 hp only used 256 cams.

als ore the ecu I think you would be better to get the stock ecu rempaped and have an s-afc for the fine tuning.

what yor hp goal agoin roy I have forgotten but remember you are looking at trackwork

meggala

[Roy]

I was surprised to read in a catalogue that 272 cams add torque and midrange??? I suspect ill be using 256. I like the idea of a little lumpiness at idle, what is the factory RB20 lift and duration, (..oh memories of my old 427 Impala at idle:D )

If the 256/260cams dont require machining i think ill be going down that path. Ill be relying on engine builder for machining and specifics, but i would like to have some input into the tune and parts in the engine, so knowledge is power

I would like to run an aftermarker ECU so that i can start throwing bits at my current engine so at least this way im not going from around 140rwkws to 250rwkws.

Instead 160 (Stock turbo + aftermarket ECU)... 220(My new turbo at 0.8bar)...250rwkws(new engine at 1bar).

Im still waiting for EMS to release their new ECU, if i have to wait much longer im going to get the WOLF.

As for goals, well power goals are a driveable/reliable (borderline over engineered) 250rwkws. As for performance i want sub 1:08 min around Wakefield, and sub 1:54 min at Eastern Creek. I guess this would equate to about a 13 flat, maybe a bit lower.

Not too concerned about 1/4 mile, but i suppose its the benchmark in most people eyes for performance.

(I cant launch a car for quids, )

[Steve]

If you want a lumpy idle, go for an ecu that will allow for a rotational idle - the first time I heard a car running this I thought it must have had huge cams - it was an rb26 and it sounded just like a GT falcon I owned many years ago.

Autronic have this feature, and I think the new wolf 3d does too.

[Merli]

whether or not the head needs machining is a function on how high lift the cams have, not the duration.

[Roy]

whether or not the head needs machining is a function on how high lift the cams have, not the duration.

Isnt that what i said?

does the increase in lift require machining of the head.

Anway arent duration and lift related, the 272 cams have something like 11mm lift. The nature of a cams lobe is that it cant increase duration without increasing lift???

Also why does everyone abandon airflow meters when running aftermarket ECUs. Some have the facility to run airflow meters. (You need a lot of cfm before you reach choked flow thru an 80mm orifice

Merli, can i ask what lap time ar eyou getting around Eastern Creek, or Wakefiled.

[GTS-t VSPEC]

I agree with Meggala, Merli and Steve. 272's are way too much for the rb20, but a set of 256's would be fantastic. If your interested in track work then you don't want more than 400rwhp, or else it becomes too difficult to handle.

The new Wolf can handle the cams fine, providing a nice smooth idle, I wouldn't suggest the stock ECU for any type of serious trackwork. The Wolf 3D Ver.4 plug'n'play versions have rotational idle, anti-lag and launch control, so they are now a good option.

If the lift is too much higher than the original then the head will need machining, but you shouldn't need that much extra lift.

See'ya:burnout:

[Merli]

Originally posted by Roy

Isnt that what i said?

Yup, but you never mentioned what lift these cams had... We're not psychics

With 11mm lift, there is a 110% chance of you having to have to machine the head

RB26DETT heads can accomodate upto 9.7mm lift without machining, and the RB20 and RB25 slightly less I believe.

Originally posted by Roy

Merli, can i ask what lap time ar eyou getting around Eastern Creek, or Wakefiled.

Although I have been to Wakefield many, many times, I have only taken this car to Wakefield once, and it was raining, and I had Dunlop Semi Slicks on the car... Suffice to say that it was a useless outing. I should be going to Wakefield again soon though...

I have been to EC once, and I was running wastegate pressure (0.7 bar - 202rwkw) because it was hot, and the car was pinging... I managed a 1:57 if I remember correctly, but I went out in the last session after learning the lines from Paul (OzGTR97), and felt much much faster, but unfortunately my lap timer had turned itself off... DUH!

So basically, I don't have any times from either track!

But I did a 51.30 around Oran Park South Circuit... That's basically the only proper time I have so far... Need to get my arse out to the other tracks and see what I can do...

[Roy]

Ok so 272, which if i recall correctly have 11mm lift , are no good. Goes to show you should be careful when reading sales literature.

But what about 2.4L, i have already got the GTR rods and found a mechanic who has worked in Japan and knows his way around these engine builds. I think ill still be sticking with 256 cams.

I recall a guy on SAU trying to sell his T-78-33D, for my liking its a little big, but i recall reading in HPI that 2.2L SR20s use the same turbo for track duties??? The price was right, but i dont have any feel for Trust turbos, does this thing equate to a 2835, 3037,3040, T51??? (or a turbo in the Garret range perhaps)

[GTS-t VSPEC]

We're using a T78 on a 3 litre(Supra RZ) and a 4litre(1UZ), and I would suggest that even with 2.4L it would be too laggy for track use.

You don't need huge horsepower for the track, a descent splash of power with a nice wide power band is the better option. I'd have thought that the 3037 would be nice on the 2.4L, more than enough horsepower and not too laggy.

See'ya:burnout:

[Merli]

T78-33D is waaaay too big dude. MIZ.33T has that exact turbo on her RB25DET, and it spools up at 5500rpm, and redline is at standard 7000rpm... Imagine when it'd spool up by on an RB20.

My HKS GT3040 makes 1 bar (when the external wastegate opens and all hell breaks loose) at 4000rpm, and my redline is at 8000rpm... Nice useable powerband.

I have just ordered 264 IN/272 EX cams from JUN with 9.7mm lift... Lift and duration are linked, but not directly... You can't say that all 272 degree cams have 11mm lift.

[Roy]

... I managed a 1:57 if I remember correctly

You make it sound like a stroll in the park. I probably overdrive my thing something silly :lol: , which isnt good for times though, and the best i can manage is 2min flat.

So in an ideal world your probably knocking on the door of a 1:54????, maybe i should move my goal back to 1:55 or 1:56

[Roy]

T78-33D is waaaay too big dude.

I would suggest that even with 2.4L it would be too laggy for track use.

... i thought so, but @ $1600 it certainly is the right price, about $1300 under the turbo im looking at.

Ill just have to keep looking around and continue to pick up parts at the right price as they become available.

Hey GTS-t V SPEC, did you ever look into running your Wolf off the airflow meter?

[GTS-t VSPEC]

Roy,

As soon as I got the Wolf I removed the AFM, I don't think that in high horsepower apps. that they are very good, but better if you concerned with fuel economy.

Merli, With the new cams your planning on putting in do you expect that the lag will be decreased? I was going to go for the 3040, but might do the 3037, do you have an opinion on which is a better turbo for street usable power?

See'ya:burnout:

[Merli]

Originally posted by Roy

So in an ideal world your probably knocking on the door of a 1:54????, maybe i should move my goal back to 1:55 or 1:56

I really hate predicting times, but I would be happy with a 1:54...

Originally posted by Roy

Merli, With the new cams your planning on putting in do you expect that the lag will be decreased? I was going to go for the 3040, but might do the 3037, do you have an opinion on which is a better turbo for street usable power?

I have no idea how the cams will affect power, or power delivery, but I'm hoping that they won't make the car too laggy.

I would suggest an HKS 3037... It'll make a crapload of power and be a little less laggy than the 3040, which is always a good thing.

[GTS-t VSPEC]

Merli,

I thought that the cams should decrease the lag, but I haven't done it myself so I suppose we will both find out once you do it.

Yeah the 3037 is looking good now, it will still produce heaps of power, but less lag=more fun, so I think that is my final choice. What size wastegate do you have on your 3040?

See'ya:burnout:

[Merli]

Tial 46mm External Wastegate... Seems to work okay...

[Steve]

Roy, I wasunder the impression that when you order your cams from someone like toda or hks, that they are acutally made up to the specs you desire, ie lift and duration - so you can just order what you want. Saves having to regrind

Anyone else done this or know for sure???

[Roy]

, I was under the impression that when you order your cams from someone like toda or hks, that they are acutally made up to the specs you desire, ie lift and duration

Yeh thats possible i suppose, but i thought gerically they were all off the shelf cams that each have been thru R&D to ensure results.

Ive considered a regrinds of factory cams, but the pricing would want to be real attractive to risk getting a dud of a cam. When the time comes i was going to approad Crowe cams and see what they can tell me.

This is where Forums like his are great as you can feedback from people with the mods so salesman cant lead you down the garden path (Not to say Crowe Cams would do that)