Introduction - Brit wants a turbo in his life and not just in his diesel volvo
 

Hi, I've just joined having read a few interesting threads, particularly on the fabrication side of things and selecting the right turbo for the 1.8 Miata engine. I have a full bodied kit car, similar in design to a Lotus 7 / Caterham or Westfied, but a little prettier. It runs a tuned ford xflow, 8v pushrod motor, which doesn't sound very impressive, but it'll take it from 0-60 in about 4.5 and shake your teeth out on the way! There are some photos in my album.

Anyway, the plan is to replace this classic motor with a 1.8 and gearbox from the Miata (MX-5 over here in UK) and then strap a sensibly sized turbo to it using a custom designed, homemade manifold and run it on a standalone ECU, such as Megasquirt or Omex. I'm looking for 200rwhp, but with minimal lag for road course driving. The car only weighs 530Kgs, so it doesn't need any more power than this.

Cheers, thanks for having me.

Laurence

Car looks awesome.


Throw some pictures in this thread, most are too lazy to go to your album.

That is a cool looking ride. Post some pics of the bare chassis if you have any.

Welcome, sylva_phoenix!

Looks awesome! I think you're definitely on the right track with your plans and it sounds like the car will be absolutely insane when you're all done. Good luck!

Why a 1.8 from a miata when so many better motors are out there?

Thanks for the welcome. Reasons for choosing the mx5 engine are several; 1 its a sweet revving twincam, which was based on the bore and stroke of the original Lotus twincam, 2 its very tuneable, 3 it requires no modification to run it longitudinally, 3 there are lots and lots of them out there, 4 parts are cheap, 5 there's a lot of information about how to do the swap, 6 it comes with a free, really strong 5-speed gearbox and finally, its cheap. I considered a few other engines, Ford zetec, vauxhall redtop, rotary, even an alfa v6. This seems the most practical choice. Fitting a turbo is probably overkill, but what the hell......

Regards

years ago, I drove a locost style car that was less than 1600 pounds with about 250 HP. It was very low, and felt insanely quick. Having 200 HP in a car weighing 500 pounds less would be crazy.

Ha ha, correct.

It will be equivalent to a caterham r400/r500, but with about 25% more torque. At a 5th the price.

don't you dare leave us hanging without video when this is all said and done.

You get "police camera action" on BBC US, right?

I don't have a TV service currently, I get my BBC fix off Netflix. Should I search that show out?

I wouldn't go calling the Miata 5 speed "really strong" but for 200hp in this ultralight, it should be just the ticket!

I like you already!

Please, please, PLEASE!!! Post some more pics!

Also: How hard is it to find parts for late 70's Triumphs over there? I need an intake plenum for a 1974 TR6 2.5L PI :giggle:

That link is nothing to do with me, just something I found on eBay.co.UK. sorry if I'm not supposed to post links to items for sale.

Cheers.

Nah, you're cool. There are almost no rules around here about that kind of stuff, unless you are spamming. That's an interesting interpretation of "good secondhand condition" haha! That's like $16 in USD, but I'm sure shipping would kill me. Thanks for the link!

That crossflow looks like a damn neat little motor. 1100, 1300 or 1600? We didn't get those in the US in anything, as far as I can tell. Looks like the engine in my friends Spitfire 1500, other than the obviously superior crossflow design. Also, tell me those are 38 or 40mm side draft Webers so I can hate at you ;)

What version of the Mazda BP are you looking at?

It's a 1660cc xflow, 8 valve all iron pushrod. This was standard issue in the ford Escort from '75 onward and pretty much formed the staple diet in terms of budget racing in the UK for about 10-20 years. It was fitted in formula Ford, rally cars, 750MC, hillclimbing, sprinting, grass-track everything really.

Mine's had a lot of work, mainly by the guy I bought it from 10 years ago.

High lift 254 CAM, flowed head, lightened and balanced bottom end, 6 spoke flywheel (2.9kg including AP sintered clutch), 1300cc machined pistons to increase CR to around 10.5:1, Unleaded, ported head, double vavle springs and light weight valve train, Bryan Hart dry sump system and, no they're not Webers. They're twin 40 Dell'ortos. It revs to about 7500rpm, but that's pushing it on standard crank and rods. Transmission is a ford Type 9 from a standard issue travelling salesman Ford Sierra running a Mk2 ecort live axle with 4.1:1 LSD. Almost all 7 type cars in the UK use the Type 9 box, hence my comment about the mx5 transmission being "strong". It's all relative.

Cheers

I was looking at a 1.8 VVT engine from a mk2.5, but I'll take any advice you offer. VVT seems like something to go wrong that isn't really necessary.

Cheers

Haha indeed the Mazda transmission is at least a bit stronger than the T9 Ford box. I used to play with Merkur XR4Tis and many would swap the T9 for the Mustang T5.

I would say that for your build you don't need to spend the extra money for the newer VVT engine. I'd go with a '99 engine -- good head, crappy exhaust but you'll be scrapping that anyway.

I shall bring the hate :giggle: Anything has to be better than the damn emissions spec Zenith Stromberg 175CDs on my 6.

I really hope you start a build thread here, or give us a link if its offsite.

Edit: VVT all depends on what you want to do to control it. You can do a super basic DIYPNP and run a BP4W (exactly like I have in my car) or you get the VVT BP6D and step up to a MS3, AEM or something like DIYAutoTune's VVTuner to control the VVT. Bonus points on the VVT motor is it runs higher compression (in the US anyway) and will make a shade more power out of the box. You don't have to control the VVT out of the box either. We have a few guys running the BP6D (01-05 US) head on a BP4W (99-00 US) bottom end on the stock BP4W ECU and it seems to do fine.

I think in EU/UK, you guys got the BPZ3 instead of the BP6D as the VVT engine, so the specs may be a little different. From what I've read, the BP4W is still the same though.

BP4W if you want simple, BP6D/Z3 if you want to make the investment to support the VVT, but you can always do this later.

Do you plan on building an engine, or just running something from a wrecker?

I'll most likely buy an engine and transmission from Ebay, where someone has decided to upgrade from a 1.6 to a 1.8, then lost the enthusiasm. I've seen a few of these go for about £250 in recent weeks. That's the engine, ancillaries and transmission. Bargain.

Regarding building the engine, I'm undecided whether or not I should fit forged rods and pistons, with a reduced CR. I'd like to avoid spending money, but I'd also like it to run without exploding!

Cheers

For less than 250HP, you can use stock bottom end.

So the little mazda engine will take a turbocharging to 250hp without any mods to CR, using standard rods and crank, not even changing out the big end bolts??
Forgive my scepticism, but I was expecting to have to at least skim the pistons.

cheers
Laurence

Why skepticism? That's what an awful lot of MX5 owners do.

Note you can't do this with cheap hacks, you need a full ECU and appropriately sized injectors.

But you don't have to touch the motor for 250bhp

Let it be said, however, that for track duty, many people upgrade the rods even in naturally aspirated cars, let alone turbo cars. I don't think you'll find a reliable turbo'd BP with stock rods. Overrev on downshifts into turns or other tomfoolery and you'll pop the stock rods.

I'd say if it's not too much of a stretch on the budget, throw some stronger rods in there. You don't need to mess with the pistons but you can if you like.

That's great news, so I can spend all my money on the management system, turbo, clutch and flywheel instead. Next question is which turbo to choose. If I want 200HP at the wheels, what's the best turbo to go for? I'm weighing up between a KKK K04 and a T25 from a 200sx. I want the fastest spooling turbo that is cheaply available second hand in the UK. From reading other posts, the KKKs are not considered to be as good as the Garrett, yet in the Volvo T5, switching from Garrett to KKK improved performance (at the cost of longevity).

Cheers

I laughed when i read super strong 5 speed but anyway. it's enough for your goals.

If you're racing you should get rods and stronger valve springs. the stock pistons should be fine as long as you do in fact stay around 200. keep an eye on what motor you choose if you have a compression ratio in mind. I'm too lazy to look it up but they are somewhere close to 9:1 early on and then go to 9.5:1 and then to 10:1.

The most popular turbo fitment for that range is the gt2554 or gt2560

A friend of mine made 200hp with a genuine Garrett GT2554R on an internally stock 95 1.8, so that's the earlier 1.8 with the lesser head. I believe Shuiend or Y8S is/was making 200+hp with a T25 and a stock block, they love posting the dyno plot in every turbo selection discussion thread. I'm sure it will show up here eventually.

If ALL you want is 200-225hp, I'd say used Nissan T25, or Garrett GT2554R or GT2560R for stock bottom end friendly power. The journal bearing Nissan SR20 T25 flanged turbos are plentiful, cheap, and rebuildable at home provided the housings don't eat the wheels. Journal bearing looses you ~300-ish rpm worth of spool, but that's not going to matter much with such a small turbo and a 7,000-7,200rpm redline. The T25 flange also gives you a lot of turbo options if you want to go bigger/ball bearing in the future.

Ok, so its a t25 turbo and and earlier, non vvt engine with a lower compression ratio (9:1) and forged rods and uprated valve springs. This all seems sensible and relatively low cost so far. Next is which clutch (ok I'm used to a sintered clutch so I'd consider anything as driveable...) . I assume I'll be onto new injectors at this point, but I can check which ones from the intro post sticky.
We're almost there with the spec. Any comments on camshafts?

Cheers

My write up is not up to date. Rx8 injectors or better

Yes, you'll need some. A pair would be best.

Serious answer: why bother with anything but stock? Plenty of builds around here with stock cams way over 200 WHP. Don't mess with success.

200hp = stock plus little boost

RX8 "yellow" = Denso 195500-4450

450cc/min @ 3 bar/43.5psi (According to 949Racing)
524cc/min @ 4 bar/58.8psi (According to 949Racing)

RX8 "blue" = Denso 195500-4460

528cc/min @ 2.25 bar/32.6psi (according to Injector Rehab)
610cc/min @ 3 bar/43.5psi (using the RC Injector Calculator)
709cc/min @ 4 bar/58.8psi (using the RC Injector Calculator)

Both are EV6 style injectors that are lightyears ahead of the old RX7 "red" 550cc EV1 injector technology, and can be found used very inexpensively. Watch out though, there are known to be Chinese knockoffs on eBay. Deatschwerks also sells drop-in EV6/Denso units, plus they are a forum sponsor.

If you want ultra-baller injectors, check out EV14 style units from somewhere like Injector Dynamics or Fuel Injector Clinic. With a proper ECU with enough resolution, a massive EV14 style injector is not an issue. We have guys on this forum running ID1000cc injectors on 1.8s with stellar idle control. Check out 949Racing or Trackspeed Engineering.

There are other companies such a FiveO Motorsport that also sell EV14s, but we have had members on here with less than positive results from this company. Hustler may be able to provide some details...

Leave the cams alone. I think you already get the more better factory BP5A-12-420 in your EU/UK spec non VVT engines, plus the unobtanium "square top" intake manifold that we (on this side of the pond) all lust over.

Do not waste money and time on rods and valvesprings for 200whp. Many people here track their cars for years with stock engines at over 200whp with no modifications to the block. There have been street cars with 280whp+ on stock blocks on this forum (Leatherface24, pdexta, etc.) that have run for years on the street with a good tune. Rods and valvesprings are only insurance in case you miss a shift and overrev the engine severely. And if you do overrev it and break it you are simply forged pistons, rods, and a billet oil pump away from turning the power up to 300whp+ if you desire.

Does anyone have list of engines, compression ratios and model number by year? Also can someone recommend an uprated oil pump with take off for a cooler?
Thanks for all the advice so far, it is extremely helpful.

Cheers.

only aftermarket oil pump is from boundry engineering (link is top right of this page). the stock one is good for your goals... just like six said they are for insurance. You can get by on stock everything most likely. It's almost easier and cheaper to buy motors and blow them up. Coolant reroute is a no brainer though. you definitely want to do that.

I agree with everything six said but would still do rods and springs in any race application. I wouldn't put it past myself to miss a shift and I don't really like pulling and disassembling motors. The motors really are good stock for ~200 all day long if they have a good tune and aren't over revved.

I'll have to weigh up the cost of rods, valve springs and pistons against the cost of trailing the car to the track. I'd prefer to build the motor strong from the start, otherwise knowing my luck it will blow up on the first outing in summer and not get repaired until it deep dark winter time.

Why are the costs of rods springs and pistons weighed against the cost of trailering? I'm not seeing the connection.

Up front cost of rods/pistons/springs -vs- cost of a tow home?

I <3 AAA Taxi :giggle:

You can be (reasonably) sure that you can drive home in a built motor after an accidental mechanical overrev. Not so much with a stocker.

Normally I drive the car to the track, but if I'm expecting it to blow up, then I'd hire a trailer at £50 a go, that way I could guarantee getting home again. AA cover in the UK are getting wise and refuse to pick up kit cars from outside race tracks. What I'm getting at is I'd rather over build the engine and know it will be reliable. It also leaves room for the inevitable "I want more power so I'll put a bigger turbo on it" that will probably happen at some point.

That makes sense. i was just confused because it wouldn't make sense to trailer it every time just for the one time it might go pop.

If you think you might go for more power later, and you're going to have the engine apart anyways, by all means... Rods and valve springs.

once you get above 200-220tq you start running into transmission stuff, even bigger injectors, new turbo, maybe a new 3" exhaust instead of 2.5", possibly a new clutch, boundry oil pump (not a bad idea to have on a track car regardless), maybe new wheels and tires, maybe a new manifold/dp.

You can keep it really simple @ ~200. cost low fun factor high.

I don't know if it's just me or if anyone else has experienced this but with my last car the higher the power got the more paranoid i'd get. All the little sounds and feels of the car I was much more hypersensitive to.

Since this car is half the weight of a Miata, in theory the tranny should be good for more than the ~250wtq it handles in our heavy ass cars right? How much more I don't know.

200 will be perfect, I've probably not got the driving talent to cope with more than that. The rear axle will be on its limit at that point too. Perhaps I'll employ the KISS principle, run a stock motor with low boost and see if I get upgrade-itis at a later date.

Thanks.

In theory yes, but I don't think a 5-speed would handle 250 wtq in a miata on the track for very long, so 220 ish wtq should be safe but not too much higher it seems to me.

Sounds like a good plan. Save that cash for proper management/injectors/tuning and you will be MILES leagues ahead of a lot of the turbo :noob:s

Sweet car, can you touch the ground from the drivers seat?

Ha, not quite, but that's because you have to reach around the bodywork. In the Sylva Striker (the same chassis, but minimal bodywork) you can touch the ground. The car sits 4 inches off the ground, but that's for clearance on the road, i.e. speed bumps. I've seen hillclimb and track cars running as low a 2 inches with modified suspension mounts, but these are full-on race cars and would get torn to pieces out on real roads.

Update, I've decided to go with the 1.6 motor, based on a few reasons:

1) from calculations picked up online, the forces at work inside the 1.6 are significantly lower than the 1.8 (piston acceleration and force on the crankshaft roughly 2/3 compared to the 1.8)
2) apparently they rev better due to the over square bore to stroke ratio
3) they are LUDICROUSLY cheap. I spoke to a mazda salvage specialist yesterday and he quoted, for a complete engine, transmission, clutch pedal, prop shaft, wiring harness, ECU and exhaust - £175!!!

I spent more than that on gaskets the last time I rebuilt my old Ford Xflow motor.

Is the GT2554 still the right turbo for the smaller displacement B6ZE unit?

2554/2560 on a 1.6? I don't see why not? :dunno: That car is so damn light weight that I honestly don't know if the additional 0.2l will make that much difference. £175 is like $285~is US... thats like Braineack cheap! :brain:

I'm sure the super mod 1.6 crew will be in here shortly to chime in. Would be interesting to see how your 1600 Ford stacks up against the DOHC 1600 Mazda.

NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO


WORST CHOICE ever.


I'd rather run a motor made entirely of formed shit. it's inferior in every way. no one will disagree*




* people who claim they like the 1.6L better because it's "revvy" dont count as people, just morons, therefore their input doesn't count.

^^ and there you have it!

The 1.8 really is better in every way. Check to find out how much one of those will run you. If the 1.6 is still too good of a deal, well that's what boost is for.

lol @ Scott.

I've killed two 1.6's. From my personal experience they feel less torquie. I finally switched to the 1.8. I should have done it after motor #1. I've also watched Brain have 1.8 envy for the last 4 years i've been here.. maybe more so in the last 3 years. They are still good for your goals though. I wouldn't base my decision on any of the reasons you listed other than budgetary stuffs. The reasons you suggested are really a bunch of crappy rationality to trick yourself into being ok with something cheaper! Sorry to call you out but none of them are really legit.

Hmm, looks like I need to reconsider the 1.8. Honestly the cost isn't much more for a 1.8, the engine management will be by far the biggest cost involved. I need to make a decision before I commit to making a manifold though as they have different exhaust headers. My gut says 1.8, but I've been advised by a few people that the 1.6 is a better engine and easier to tune. Perhaps that's just because more people with a 1.6 decided they needed to tune it as it lacked power in the first place. Obedience plenty of time to decide as I'll have to sell my current engine to fund the project and nobody will have the cash until February. It's traditional in the UK to massively overspend at Christmas and then live like a caveman through January.

Those people are idiots whoever they are, the two engines are as easy as each other to tune. As for the better that's entirely subjective, they rev the same** but one has 200cc more displacement.

Hell if anything the 1.8 is slightly easier assuming your ECU of choice supports sequential injection as the stock 1.8 ECU does. Makes tuning idle that much easier.

** Some people think the 1.6 revs better in the UK, but that's a misconception. In the UK the 1.8 engine cars had a longer final drive which made the 1.6 feel peppier and the 1.8 a bit more leggy.

1.8L vs my 1.6L

I'm running about 13psi and he's running about 8-9psi.

Very similar setup

https://www.miataturbo.net/attachmen...ine=1356095614

notice how mine's a POS.



The 1.6L is a bastard child motor. It's not any easier to tune; they are essentially the same motor. It's easier to make less power with it, so it's easier to be slower with it.

Please stop taking advice from 70 year old grandpas that enjoy chrome accents and luggage racks and actively engage in discussions about the best all-season tire for driving in parades with costumes on.

:bowrofl: