Ok engine builders of Great Britain you’re on!

[260Z TT]

A big fat zero for me too Rob, turbos have just come off for upgrades to motor. I have also been rebuilding my Cherry turbo for daily use, as I can not use my motorbike with my back problem for the time being.
I shall be out soon, and my aim is for Silverstone meeting, then the L6 drag record to follow!!! Tee hee!

Mark.

 

[racer]

There seems to be some confusion here over RW/hp and flyW/hp figures that are quoted at a Rolling rd. All rolling roads measure Horspower at the wheels. They have to because the tyre is connected to the roller not the Flyweel. BUT! After that figure is atained the calculated Losses will be added back onto that figure and a printout produced. This is the figure that ALL rolling roads give to there customers because it's the biggest one, the best for bragging to your mates down the pug with and therefore the best for Bussiness! I've yet to find a rolling road(I've been to a few now) that does it and any other way.

 

[spyro]

Nonesense. on my Z the RWhp and FWhp are exactly the same.

that is, Rear wheel HP and Front wheel HP...

ahem

 

[240z]

I've yet to find a rolling road(I've been to a few now) that does it and any other way.

Thor racing (see this months Banzai), always do power at the hubs, which is sometimes quoted as at the wheels by the misinformed.

I personally think this is better for high power 2wd cars as you don't need 3 people sat in the back ensuring you don't get wheel spin, which increases sidewall flex, tyre surface area, and gives a lower/unpredictable rwhp figure. Hubs are the closest you can get to the flywheel without an engine dyno, and is the most repeatable/predictable way.. in my opinion.

I have no idea what power at the tyres is for my car, as I can only predict what the tyre losses would be, but will be going back to the same hub dyno soon with a new exhaust to see how it compares..

 

[SKiddell]

Go for it Phil....look forward to seeing you run this year, looks like supermod may be hotly contended though

 

[240z]

Go for it Phil....look forward to seeing you run this year, looks like supermod may be hotly contended though

Thanks Steve, yes I'm under no illusion that I'll be I'll be one of the quickest this year, just got to put some practice in and see how well it pays off!

This is the figure that ALL rolling roads give to there customers because it's the biggest one

I must also add that that, I do agree with Racer that every other rolling road I have been to have all quoted the calculated flywheel figure..

 

[Mr Ex]

Mr Ex, we have to meet up - I love your friendly bedside manner - so refreshing ! Do you 'rouge, blanc, rosé, champagne, apéritif, digestif or bière' it ?

Talk English then you'll find out!

 

[Legendary5]

So, where are you Guus - two months has gone by, useful preperation time !

???

If you got the goods , top quality takes time

 

[SeanDezart]

top quality takes time

Don't I know it !

And the goods are always available AND you have an impressive collection of parts already !

 

[zedhead260]

I shall be out soon, and my aim is for Silverstone meeting, then the L6 drag record to follow!!!

Current L6 record sits with Dean Botteriell who ran 12.69 @ 117.41mph back in 1993 (I’m sure you know that anyway) – so that’s the target.

This has the potential to be piped by Ben Stapley’s Janspeed car who ran a 12.793 @ 109.61mph at last years Bruntingthorpe thrash. Better traction at Santa Pod could claw in a couple of tenths.

What’s interesting is the 7.8mph difference in terminal speed (doesn’t sound much, but over a quarter mile it is not insignificant).

Making a base assumption that Dean’s car weighs in at an average 2500lbs* including the driver; rear wheel hp calculations based on elapsed time give him a peak of 242bhp made available for him to achieve that time.

But with a big squirt of NOS coming in at some point during the run, working it out on terminal speed, I calculate a whopping 316bhp to cross the line at that speed once the wheels were fully hooked up to the tarmac.

As is the case with all the high horse power cars, how well the power can be transmitted down to the track is the critical factor in pulling off a good time. But with 428bhp Mark, I feel it is there for the taking.

* actual weight required for true calculation.

 

[Ian Patmore]

Another question......there are posts here and elsewhere saying how much horses thats being produced, but what about street N/A L series zeds that are producing as near as/equal/or just above 100bhp per litre? I get the impression there are none/very few, why is this? Lack of knowledge to obtain this/ parts /development/cars as this level are not "streetable"/cash/owners preference? Other parts of the world seem to manage this highest point...why not here?

Regards
Ian

 

[SKiddell]

IMHO Ian whilst there are many people in other countries "claiming" to have 100 BHP/litre (normally aspirated)... few of these are
verifyable....many are pub figures and lack any scientific foundation, thats not to say it can't be done just that we have to "weed" out the wheat from the chaff so to speak
100 BHP/litre is BLOODY difficult to get out of ANY normally aspirated engine never mind the single cam non cross flow L series, without major investment in both time and money... I know I have tried

Another fly in the ointment is the BHP fixation that never gets really discussed.....BHP is only a factor of torque multiplied by RPM and yet torque is hardly ever mentioned even though it is a better indicator of "grunt"

In order to get close to 100 BHP/litre, major major surgery is needed such as welding the head up to get compression ratios up to and exceeding 12:1 (have seen figures 13+:1)....10:1 and below just wont cut it.
Serious investment is needed in porting/polishing
Race fuels
Biggest valves possible sometimes exotics such as titanium etc
Big lift cams (try 600 thou plus )
Custom inlet and exhaust systems (experimentation in runner length)
Custom fuel systems such as throttle bodies
Intruded crown forged pistons (also raising compression and maybe improving the flame front/burn)
Exotic rods (rod/stroke ratio)
Race prepped cranks/blocks (to withstand the increase)

The real kings of L series tuning are the Japanese who achieve credible and verifyable figures but even then we are talking 320 - 330 bhp out of the most out and out modified 3.1/3.2 litre screamers. Across the pond the likes of Rebello etc dont profess to get any more.

All of these mods leave the car less and less streetable every time even the great Sato san intimates somewher on his brillaint web site that his car is not the sort of thing that you would want to drive to the shops in as power is made much higher up the rev range than a normal car would be (if you can find the dyno traces check out power under 4000 rpm)

When the new 3.0 litre gets built I must admit I am hoping to get close to these figures but its going to take A LOT of work and £ and take probably wont happen before next season.

One factor is parts and engineering availability in the UK....your good self for instance had a head prepared in the US
The Japanese have considerable access to wonderfull cams, headers etc from the likes of Kameari etc plus their workmanship and passion is absolutely without equal.


Just my 2 farthings worth

 

[twoforty]

My brothers Honda s800 kicks out about 90bhp, its been bored to 880cc but that's pretty close to 100hp/Ltr not bad for a 40 yr old car

 

[Ian Patmore]

Yes, I should have said real figures rather than down the pub claims. Your 2 farthings is probably a fair sum up. I think the major factor in all this is getting your cylinder head flow and cam right is the most fundamental part. Everything else "joins" to this.

Yes, also to the engineering avail. here. Whats here is so limited, I went to the US for my head build to try something different where their engineering availabilites and knowledge are more developed (only in the sense of having a more diverse pool of L series tuners over the years) And the cost was a 1/3 of the cost of having something similar done here.

And yes, oh yes, TORQUE is whats it all about....

Your input is appreciated on this question

Cheers
Ian

 

[ZHead]

Torque (t-o-r-k) : that thing that V8s produce in abundance and instantaneously, much to the annoyance of anyone suffering turbo lag.

NB : Contrary to popular belief, Japanese engineers DID NOT invent turbo lag to give V8s a chance This is a myth that will not be tolerated and will be dispelled at any and every opportunity

Torque is what it is all about - that is why so many modern Japanese cars with HKS this and Jun that produce loads of horsepower but are pigs to drive and still do not put down 1/4 mile times that you would expect from so much horsepower.

Sounds like the L6 record is within your sights and your grasp, caveated by the hidden demon known only as traction. GOOD LUCK, this will be a hotly contested record over the next couple of years.

Now if I was a betting man ......................

 

[grolls]

Sounds like the L6 record is within your sights and your grasp, caveated by the hidden demon known only as traction. GOOD LUCK, this will be a hotly contested record

Not wishing to put a damper on Skiddies attempts, but I do think that the old records should stand as carb versions as it is easier to beat an old record using modern equipment ie; Tyres, diffs, injection,lightweight stuff, modern track tarmac etc.

Skiddies car and others should be benchmarked for us all to aim for.

 

[SKiddell]

Ian, I love the work Braap (Rusch motorsport) did on your P90....looks stunning and I cant wait to see how it performs.....but please when you get it running you must go to the only dyno that doesnt lie....the black one at Santa Pod....If only to put the car in the record books.

One thing worth remembering is that a certain Dave Jarman was producing very big HP (in excess of 300) with his modsports car so in fairness we do have the expertise in the country, and its Dave who has taught me the most about L series engine design, without his guidance and his cylinder head I wouldnt be in the same league as some of the faster L28's with triple thingies.

Grolls, you really like your chestnuts dont you, even the old ones
Interesting that you should "pin" the current L6 (na) record on the use of modern technology. Dont forget there is another L6 out there also on exactly the same throttle bodies, modern tyres, trick diff and in excess of 3 litres, but its still a little way off even high 13 seconds.....but by your reconing, because it uses throttle bodies it should be right up there, I'm afraid its not that simple. (and please dont say that Santa Pods tarmac is more modern than it was 10 years ago cos thats co88lers..... I've done several 13.7 runs at York on crap Khumo tyres, no trick diff and a surface that would scare Colin MCrae).

Throttle bodies or "modern equipment" as you call it, are nothing if the engine doesnt breath right and in order to get that right everything else has to work together........

And for the record.....Nissan motorsport were using throttle bodies in the early 70's on Z's so its hardly modern equipment.

To use an analogy, Jesse Owens ran a 10.3 second 100 metre at the Berlin olympics in 1936.......today Asafa Powell runs it in 9.77 with the use of "modern equipment" but its still 100 metres and no less of an achievement.....I dont hear the olympic committee calling for the disqualification of Mr Powell and the rules changed so everyone has to wear leather shoes and cotton shorts
Mute point really and not defendable Mr Grafton.....NEXT

 

[zedhead260]

but I do think that the old records should stand as carb versions as it is easier to beat an old record using modern equipment

LOL Mr Grolls – That is the whole point of records; they get better and better over time.



Historic world record breaking - that's a good one.

 

[SKiddell]

Historic world record breaking

LMAO........almost a dichotomy in itself.

 

[twoforty]

Steve, did you sort your brake problem?