Guess what my MPG is on new L28?

[EricB]

Hi all,

I'm still reeling... pardon me.

So I just finished my first full tank after the initial approximate 500mile break-in period of my F54 L28 with early E88 and larger N42 valves.

On 12 gallons I managed 246miles... Granted 75% of the driving was on the freeway at a constant 70-80mph but NEVER did I expect to be getting slightly over 20MPG!!!!!!!!!!!!!!!!!!

I have an O2 sensor plumbed in the exhaust just beyond the header collector and it shows barely a tick over stoichiometric, I've checked the plugs and they look fine too... Wow... It appears to be running just fine, feels plenty more torquey than before - love it!

Even more impressive is that my tired matching # L24 was getting at the most 15mpg on a good day with the wind in it's back...

-e

[e_racer1999]

awesome! i hope that my engine (after i build it) comes together as nicely as yours has

[SteveK]

Hey Eric

How are you doing

Glad to hear that your new settup is woking out

Just to let you know that your carbs are also running on a newly built L28, N42 big valve head, stage II cam, Vernier pully

And it has just been dyno'd by one of the most reputable competition engine builders in the UK (Wilcox race engines)

Bear in mind these guys develop for Truimph motorcycles and Rover cars and build $20,000 upwards race engines for many people across the globe

160 BHP @ 5500 at the wheels (somewhere around 200+ at the fly)

A flat torque of 170 ft pounds from 2500 to 5500

All they had to do was change the main jets from the 115' s that were in them when you sent them to 120's I am still running the original 30 mm chokes

[RIP260Z]

Hi SteveK,

I am considering using Wilcox to tune my engine setup when I have rebuilt it (its going to the machine shop tomorrow)....I take it you would recommend them?

And this is my first post......off and running

Cheers

Ian

[SteveK]

I am working on a write up for the UK Z site but

Here’s a heads up

John Wilcox has a multi million pound business solely dedicated to precision race engine building and the scientific analysis of the entire process.

They will not generally do rolling road testing for any old jo bloggs (saxo owners be warned)

The way I found out about them was through Duncan Pearcy from the Z farm who built my engine, he mentioned that Dominic Frattaroli has been to them for many years.

So I phoned Wilcox’s and chatted with the receptionist whom I thought was very knowledgeable -- She turned out to be the Wife of the owner (her name is Rita and she is absolutely brilliant) I almost went through an interview on the phone.

She told me the waiting list could be several weeks, which didn’t deter me so we continued and I booked in

Five weeks later (I was running my engine in so no big deal)

They spent 3 hours, they tested several sets of jets (on triples so x 3) optimised fuel flow, fuel air ratio, and ignition for best power, economy and drivebility, found me 25 hp extra and flattened the torque curve off.

They called this a “rough” set up.

I then got a guided tour of the site by Jon Wilcox and it blew me away

Having had 25 years in engineering I hadn’t seen anything this good since my days in a research establishment for the National coal board.

They have a full machine shop, electronics workshop, engine build clean room, 1000 bhp sound proofed water dyno and NASA control center, 225 hp eddy current dyno and the rolling road.

But be warned, whilst testing they will not let you anywhere near the rolling road area as it is regarded as confidential, they develop for many high end applications and companies so have to preserve client confidentiallity. This was the hardest thing for me as I (like all of you) am protective towards my car.

They definitely get big thumbs up and were not that expensive, considering the expertise that was at my disposal.

The most important thing is that I trust them and the figures, they are one of the few dyno’s that is used to test and develop engines for major motor companies and as such stand the best chance of being accurate (as much as could be). Their figures are the ones quoted in book and manuals.

They ship engines all over the globe – if they can’t do it, it can’t be done

I am proud to say that my car has been tuned (no matter how mildly) by these guys.

Once again Eric sorry for hijacking

[zhead240]

20 mpg that sucks!! i thought these cars got aroung 30 mpg or higher. my pickup get 20mpg ( v6 94 gmc)

[SteveK]

zhead240

They will get close to 30 mpg in standard form but when you start to modify and tune them for power, gas mileage suffers.

Each to their own really, you can stay with a cast iron exhaust manifold, twin SU's and 150 BHP at the fly wheel (if your lucky) or you spend zillions of pounds, every waking moment and end up with a wonderful smile every time you pass a d*** wad in a BMW who thinks he drives the be all and end all of motors -- personally being able to do the best part of 100 in 3rd is a thrill on its own.

Think yourself lucky, I live in the UK where petrol is about $6 per gallon but the buzz it get outweighs the cost every time

[zhead240]

i see your point but get caught doing 100mph two times and your walking for a year or two and when you do get your licence back you can't afford the insurance.( that's if u can get insurance)from what i hear on this site,stock L24s are pretty zippy at 150 hp.i'd rather get 30mph.i guess to each his own.

[Zs-ondabrain]

by my calculations, thats about $11.00 US per gallon @ about 1.86?? exchange rate. i think

www.xe.com/ucc

[Zrush]

Originally posted by SteveK

zhead240

They will get close to 30 mpg in standard form but when you start to modify and tune them for power, gas mileage suffers.

So true, less then 10mpg on the my 77 280Z. Oh well, at least I can get to the gas station fast

Vicky

[sblake01]

The best mpg I ever achieved in my basically stock 78 w/a later model 5 spd. is 28.4. That was on a trip up north, all highway driving. The best I ever achieved in the 810 (L24E) is 26.6. Smaller engine, heavier car, lower 5th gear. I have never heard of a Z carbed or f.i. actually getting 30 mpg. I was hard pressed to get that back when I had my 510 and it was stock.

[Inf]

I remember seeing a post a long time ago on zcar.com from a guy claiming to have gotten 35mpg ONCE on one trip that was all highway. He had ztherapy SUs, an n42 head and some headers on an L28 iirc.

He mentioned he got 28mpg usually during "normal" use.

Not sure if this is one of those fish stories or something, but I was impressed