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all this dyno mumbo means sfa, i honestly think if u went for a drive in my car u would change ur mind

Personally I'm onto my 4th RB30, with lots of different turbo combinations and I've been doing them since 1999 when the first one went into an R32GTR. Actually a couple of years before that, when we built an RB30 with an RB20 top end, now that was a head buster. All up I think we have built around 30 x RB30's in both 2WD and 4WD configuration. Maybe my tastes are different because I come from a long time circuit racing background, I just can't tolerate any lag, slow throttle response annoys the hell out of me. I simply can't drive a car anywhere near the limit without pin sharp throttle response. That's what I do, that's why I build them the way that I do, that's where my satisfaction comes from. I'm not saying that I'm right, all I am saying is I know what I like/want/need out of my cars. If it satisfies your requirements then I am very happy for you and I truly hope that you enjoy it for a long time.

Cheers

Gary

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Sorry I did not see the second graph when I posted...so I will edit this post.

As you can see there is a subtle difference between the 2 graphs. The power curves looks exactly the same.

However when you analyse the power at specific speed, the dyno run in lower gear always give higher reading.

Dyno operators should print out rpm vs power/torque rather than speed for ease of comparison.

The coventional thinking though is that 3rd gear makes more power...well there is a poofteenth of a nats d1ck in it if you work it out as a percentage of overall power. Next time im on a Mainline ill do a back to back without restrapping the car. Id say it will be almost identical. Jim from Croydon commented to them about how hard they had the car pulled down on the Saturday, so on Sunday the car wasn't pulled down as hard so it made a little more.

Anyhow...back to you Marko.

Edited by DiRTgarage
The coventional thinking though is that 3rd gear makes more power...well there is a poofteenth of a nats d1ck in it if you work it out as a percentage of overall power. Next time im on a Mainline ill do a back to back without restrapping the car. Id say it will be almost identical. Jim from Croydon commented to them about how hard they had the car pulled down on the Saturday, so on Sunday the car wasn't pulled down as hard so it made a little more.

Anyhow...back to you Marko.

We all know that there are dyno variations etc etc etc and we should not compare these dyno graph....but lets ignore that.

What you are referring to is the power and torque vs rpm graph.

If there is enough drive train power loss between 3rd and 4th gears in the gearbox then it will and if there isnt significant difference then there won't be any difference in power /torque vs rpm. It's the rule of energy conservation.

What I tried to point out, is that when you plot that out on a power/torque vs speed graph, then the graphs are different between the 2 gears.

Look at it carefully enough and you will see that your 2 graphs (abit different days) showed that the car appears to be more responsive in 3rd than 4th gear on your own setup. If you still can't see that, then next time your car on the dyno, get 2 print out in 2nd and 4th gears. You will see the difference.

So you shouldn't post up a 3rd gear power vs speed graph and compare it to some else 4rd gear dyno printout and discuss response.

BTW while we are at it, can you post your dyno graph with race fuel at full boost for some more discussion? Would you mind this Marko?

I just can't tolerate any lag, slow throttle response annoys the hell out of me. I simply can't drive a car anywhere near the limit without pin sharp throttle response. That's what I do, that's why I build them the way that I do, that's where my satisfaction comes from.

Cheers

Gary

point taken - i have the perfect solution for you gary...get a v8 :D (then again, dont bother)

To be honest, I am in the same boat as Marko. I've never driven anything with a rb26 that is as impressive as the RB30.

what i will say is that the boost of my new setup comes on much stronger (due to making more power) & 'feels' that it comes on much sooner than my previous rb26 with hks gtss (when the wife drove the car this is 1st thing she commented on, the response)...if i compare it to my 1st setup which was an rb26 with gtrs, well, i'll never do that again lol

perfect example of what 9krpm is talking about

same power of course. but in two different gears one would look way more responsive than the other with speed as the y axis.

post-3621-1248232849_thumb.jpg

point taken - i have the perfect solution for you gary...get a v8 :D (then again, dont bother)

Too late, decades too late in fact. I have had quite a few of them, I'm currently doing some work on 2 push rodders at the moment. One is Nascar Chevy 6 litre, 850 bhp with a 10,500 rpm limit that's going into a circuit race car. Swapping from methanol carby to E85 injected, it won't lose much. Now that is an engine with serious throttle response. The other is going into a '69 Camaro road car, it's a 574 cube Chevy crate engine, yes that's 9.4 litres. Out of the box with 725 bhp from a carby on pump 98 but not for long, it's getting a multi throttle set up like Stuart's R32LS1.

Sorry, too far off topic

Cheers

Gary

perfect example of what 9krpm is talking about

same power of course. but in two different gears one would look way more responsive than the other with speed as the y axis.

That’s why I always like to work out the engine rpm.

Cheers

Gary

Too late, decades too late in fact. I have had quite a few of them, I'm currently doing some work on 2 push rodders at the moment. One is Nascar Chevy 6 litre, 850 bhp with a 10,500 rpm limit that's going into a circuit race car. Swapping from methanol carby to E85 injected, it won't lose much. Now that is an engine with serious throttle response. The other is going into a '69 Camaro road car, it's a 574 cube Chevy crate engine, yes that's 9.4 litres. Out of the box with 725 bhp from a carby on pump 98 but not for long, it's getting a multi throttle set up like Stuart's R32LS1.

Sorry, too far off topic

Cheers

Gary

9.4ltr in 1 of my favourite cars (ss camaro) - u dont fark around gary! got pics?

9.4ltr in 1 of my favourite cars (ss camaro) - u dont fark around gary! got pics?

Way off topic, but it's your thread, this is what it looks like now

gallery_1903_3392_56787.jpg

If you know your Camaros you will recognise this one., it's the look the owner is going for (no, this one is not going to be mine) but without the headlight covers

camaro1.jpg

2006-foose-69-camaro-9w.jpg

We are going for the Minilight style wheels as per Bob Jane's Camaro

12b.jpg

The 572 in CF's has Hogan single throttle body injection, we are going multiple, the same guy who made Stu's inlet system is making the one for this engine

camaro7.jpg

My job, as usual is to tune the suspension, it's a long way from the standard layout, 5 link, watts linkage, Koni 3 way adjustable coil overs with rocker actuation on a Moser 9" rear end with 32 spline axles, rack and pinion power steering, the front also has 3 Koni coil overs with tubular double wishbones, 2" drop spindles etc etc.

RPSS-FD_ID.jpgFCOC-FD_rear_compact_ID.jpg

Should go OK, it'll be about 100 kgs lighter than an R33GTST with around 750 bhp and 750 ft/lbs of torque. If I like it I would like to build one for myself, other than the body restoration (lots of rust to fix) it's just a big kit car, all the parts are off the shelf from the US.

Cheers

Gary

bob jane camaro looks tough - i was watching barry whites show last night 'from wrecks to riches' building up a silver 69 with matt black stripes, 383 blown...what a beast! i also love the hemi barracuda.

sorry guys...back on topic lol

Someone was asking about flow figures for Markos head. My laptop on the flowbench shat itself a couple of weeks ago, I have all the figures on a memory stick somewhere here, just need to dig it out. I've attached some figures for a head I just finished this week, similar to Markos but with .5mm o/s valves. Std and modified flow curves are plotted. This head has standard shaped chambers, standard sized port openings, radiused/5 angle seats, a fair amount of bowl and short turn work and the exhaust bump removed. The tests were done with a radiused intake bellmouth the same size as the standard manifold. All readings are at a depression of 28" water.

Markos head was a touch less on the intake, very similar exhaust. It is possible to get much higher cfm readings but it kills air speed. For peak power it would work ok with a much bigger port but what you lose in the low to mid lifts isn't worth it. Increasing the exhaust port opening does pick up about 25cfm but the manifold kills it anyway so I prefer to keep it small and stop reversion. intake/exhaust percentage is up a fair way most of the range until it hits the higher lifts where the exhaust valve size kills it. I just finished an evo9 head before this one and they make an RB26 look fairly average, I'll post up a graph for it if anyone is interested.

post-8303-1248301898_thumb.png

perfect example of what 9krpm is talking about

same power of course. but in two different gears one would look way more responsive than the other with speed as the y axis.

post-3621-1248232849_thumb.jpg

i replotted my 3rd and 4th gear over each other last night and it looks nothing like that...one line is just under the other...ill scan it for you if you like.

scan0003q.jpg

Edited by DiRTgarage

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