Dax Rush Engine Choice

[CorsaScott]

Well, funds have been released, allowing te start of a little project . The Kit shall almost certainly be a Dax Rush, however engine choice is leaving me stumped. Basically, I have a budget of about £1000 to £1100 to pay for an engine, and a rebuild for said engine, replacing a lot of stuff so that when the engine is slotted in, it's running well.

Now here in lies the rub. What can I get for my cash? Originally, we were thinking 2.0 n/a, but looking at power figures etc. we've decided that we'd like a bit more power. I suggested 2.0 turbo, however my dad is concerned about heat with the turbo, so then I got to thinking, why not whip the engine out a 325, straight 6 will sound the nuts, get a decent power figure (190 is plenty) and keep it n/a so avoid the heat problem. So my question is, am I likely to get myself an engine (donor car prefered) within budget, and the biggest question, will fitting be a hassle?

[Paul Drawmer]

Whilst I am an unashamed fan of BMW engines, I'm not sure this would be a good idea.

Any BMW 6 is going to be heavy compared with a 4 cylinder, and the shape will certainly mean that the CofG will move forward, increasing the steering weight, deadening the steering feel, and spoiling initial turn in.

I know that there are plenty of Daxs out there with heavy engines, but at least with the Rover V8, the weight is further back, and you would have V8 burble.

Personally, in a 7 type car, I think that the whole thing is about low weight. I'd be aiming for the nimble, rather than the tarmac bruising approach.

The reason so many 7 types have K series, Zetecs, and Duratecs, is because they work well in that type of car.

If you MUST have the BMW 6 - then build a Hawk Ace.
http://www.talonsportscars.com/project-hawkace.php
The engine suits the car perfectly.

[Shaun_E]

Ford Zetec 2.0 or, if you can stretch to it, a 2.0 Duratec. What about a bike engine?

[The Black Flash]

CorsaScott said:

Well, funds have been released, allowing te start of a little project . The Kit shall almost certainly be a Dax Rush, however engine choice is leaving me stumped. Basically, I have a budget of about £1000 to £1100 to pay for an engine, and a rebuild for said engine, replacing a lot of stuff so that when the engine is slotted in, it's running well.

Now here in lies the rub. What can I get for my cash? Originally, we were thinking 2.0 n/a, but looking at power figures etc. we've decided that we'd like a bit more power. I suggested 2.0 turbo, however my dad is concerned about heat with the turbo, so then I got to thinking, why not whip the engine out a 325, straight 6 will sound the nuts, get a decent power figure (190 is plenty) and keep it n/a so avoid the heat problem. So my question is, am I likely to get myself an engine (donor car prefered) within budget, and the biggest question, will fitting be a hassle?

First off, you need to go here: http://forum.daxsportingclub.com/

Loads of people have cossie turbo Rushes, some running truely bonkers amounts of power, so I wouldn't worry about heat too much.
You can also improve airflow through the engine bay by having the flared aluminium side panels (standard on the bike engine car, but you can have it as a no-cost option on the car engine one too).

I'm pretty sure that the straight 6 wont fit as it's very long - it was discussed on the forum just recently in fact.

Another option might be to go for the lightweight bike chassis with a car engine, a few people have gone that route now with honda s2000 power plants.

Your turbo idea is probably best I'd say. You might also consider a supercharger? Eatons from Minis go on ebay for peanuts all the time, you could strap one of those on a 2.0 engine, and as long as you run low boost (<6psi), not have to make any expensive changes.

[Furyblade_Lee]

as Paul says, I think a BMW six is a bad idea. If you HAVE to, make sure it has an "M" on the rocker cover! Bike engines aren't for everyone, but if you do go the proven Dax Rush BEC route you will not need to rebuild a bike engine before installation. Just a clutch upgrade and maybe a sump mod, just rag it until (if) it goes pop.

[Furyblade_Lee]

echo the S2000 engine, awesome. My mate is putting one on a Fury at the moment.

[kennyrayandersen]

Furyblade_Lee said:

echo the S2000 engine, awesome. My mate is putting one on a Fury at the moment.

I echo the weight of the straight 6. I was looking at one of those new kits that are supposed to make use of BMW engines since we don’t have many RWD donors here in the states, but I was frankly disappointed in the power to weight of the BMW engines. I think you need to rethink your engine budget.

The Honda is nice and all, though a bit low on torque (probably not a big issue in such a light car), but it’s pretty tall. It will fit in a Westfield and even a MK, if you dry sump, but the engine s are pretty expensive. I’ve heard that the Dax has a pretty big engine bay (or so I’ve heard) so maybe that’s not as big an issue as the cost would be; they’re going for nearly $5K USD on this side of the pond and I don’t think they are too cheap over your way either.

From what I gather, the Zetecs are cheap, but everybody is making the shift to the Duratecs due to lighter and more HP. At 160-170 HP, you could drive it now and upgrade as you go along. I don’t think it would be so far out of you budget to go Duratec.

The Nissan might be another option. I’m not sure about the UK, but the SR20DET is selling for about $2200 USD, which is pretty close to your budget. They are quite tunable, though I’m not sure on the weight. The biggest worry I would have is that once that turbo spun up in such a light car all hell would break loose… maybe that’s what you’re looking for? lol

[pilbeam_mp62]

I think your budget will allow you to buy a Red-top Vauxhall 16 valve engine - I ran one in a hillclimb Westfield a few years ago, and with a pair of Weber carbs, you should easily see 200 bhp.

Regards

[Twobad]

I'm running a turbo'd Dax and heat isn't a problem even with a GRP bonnet (with insulating mat on the underside). However, you'll struggle to get a half decent turbo engine for that money. As has been said before, the BMW option has been discussed in some depth on the Dax forum and is not a good idea by all accounts.

I'd go with the 16V Vauxhall mentioned above or a Duratech. It also depends on how you intend the car to look at the end. If you were thinking of a windscreen etc. then perhaps it might be worth considering a bike engined car with a stripped out look with no screen, wipers or heater. They can be easier to get through the approval loop (less to fail on) and you could use the money saved to spend on the engine.

A screen etc. can always be added at a later date when you are already on the road.

Edited by Twobad on Thursday 29th October 12:17

[Furyblade_Lee]

re: the Honda S2000, my only encounter with one was at Bruntingthorpe in an MK Indy. Bearing in mind the MK is not the most aerodynamic thing in the world, and mine certainly is a lot better, we were using about 3/4 mile of back straight there with no restrictions. When my car hit it's rev limiter at about 133 he came blatting past me.... Awesome. I think my mate paid about £2,000 for his engine, 6-speed box and wiring loom. About another £700 gets you the ECU to make it work in a kit. OK, 3k is not exactly your budget but you WILL get R500 / R400 performance from your DAX with 100% Reliability from your 240 / 250 bhp. How much does the Caterham Duratec cost for that power? £10k? I do not think the torque will really be an issue....
Re: Turbos in a 7-esque, I would advise against it if you want a balanced circuit car. Drag racer yes, but with no driving aids all that torque surge mid-bend will give you armfuls! A mate had a Striker Turbo, only about 210bhp but he said it was fun in a straight line, not so good everywhere else. Ruaris Cosworth Fury was incredible saying that.

Another thing with the S2000, it is tall but there is no advantage to dry sump it installation wise as the lowest point is the gearbox apparently. If I were building another, S2000 is what I would save up for.

[MKnight702]

For low centre of gravity and six speed box, how about an RX8 231 engine? No idea about price but my wife's RX8 is great fun and losing a lot of the car's weight in a Rush could only help.

Alternatively, how about the MX5 engine & box, should be cheap as chips by now and plenty of tuning upgrades available for later.

Personally, the V8 option always sounds good (in every sense). I had one in a Marlin Roadster and it was superb.

[CorsaScott]

Wow, didn't expect so many replies, cheers guys. So my fears were right, the 6 won't go in. Regarding bike engines, I'm all for them, however my dads not as convinced, put off by the work needed to convert it aswell, although how much work/money does it take to get one ready to drop in?

In terms of how stripped out it'll be, this is going to be a weekend blaster/track slag for us, since we both have our daily cars, so it'll be 2 seats, gear level, steering wheel, minimal dash and that's it, so we are looking for something quite wild so the turbo kick would add to the experience, however we do still want to have a screen since it'll be used on the road a fair bit.

I'm taken by the idea of the honda engine, RWD donor so none of that to worry about, power figure that pleases me (with space to supercharge aswell in time :P) but revvy aswell. Our budget could stretch, we used £1000 as a benchmark to see what we could get for that money, but always said if the right engine popped up we had the spare funds to get it. It all depends on how much work would be needed on the engine before it went into the car, if it didn't need a rebuild for example, that would save a lot of time and money, so could then put that money towards a better engine.

Being realistic, total price of the car we could go to, would be about £11k, but that's including absolutly everything we needed (but discounting renting a unit to build it in obviously) and as it stands, it seems the kit for a Rush is rather expensive (slightly more than we expected once everything was totted up) coming in at I think just over £7k, so really that leaves £4k for everything else.

[The Black Flash]

That being the case, I'd definately go the bike engine route, with a car scuttle so you can add a screen. It's a lighter chassis and body to start with, so you "need" less power, and it should handle better too. And I'm pretty sure that, say, a 1000cc bike engine in a bike chassis will be faster than a 2L car engine in a car chassis round a track.

As I understand it, fitting a bike engine is pretty easy - I don't think you have to do any special conversion work, they take the engine and gearbox as a single unit. Plus you get paddle shifters . Give 'em a call and talk it through.

[gingerpaul]

It's all been said already but I will agree with those who think a bike engine is the way for you to go judging by your intended use. The S2000 appears to be a good and proven choice now too though. Don't forget that on top of your £1000 engine budget you will need to set some money aside for an exhaust. They can be quite expensive. The exhausts for my V8 cost more than twice as much as my engine and gearbox!

[kennyrayandersen]

Since you are talking about what would be pretty much a dedicated track car (which I didn’t get from your earlier post, I must have missed something), I’m changing my vote for a BEC. I wouldn’t want one for driving around, but if you are going to race it, then I think a bike engine car would be faster around the track (especially if it’s a windy one). Your budget probably doesn’t allow for the big Suzuki HB but there are other choices. By going with the bike motor, you can keep the weight of the car down etc. You sound set on the Dax, but I wouldn’t rule out something even smaller and lighter if you go BEC (I heard it was a bit bigger than some, but I could be wrong – anyway, I’d be most concerned about weight if it were meant to be a track car).

I’d rather have one that I could drive more on the road, so for me I don’t want all that screaming waah, waah, waah going on, but for a track car I think the BEC makes more sense. The point about price with regard to the exhaust is well taken, and I think also there is usually some other hardware (read money) to make the BEC happen (especially if you want, or need, reverse).

[anonymous-user]

Been vaguely looking at building a Dax Rush myself. The idea of a turboed Rush does appeal, but as FurybladeLee says a few posts back a torque surge mid-bend can make things unexpectedly interesting. Thus looking at the possibilty of the Quadra version of the Rush. From what I recall these used the the 4wd Sierra drivetrain, which I guess now are as common as finding an MP who hasn't milked the expense system.

Edited by anonymous-user on Friday 30th October 00:07

[pilbeam_mp62]

kennyrayandersen said:

I’d rather have one that I could drive more on the road, so for me I don’t want all that screaming waah, waah, waah going on, but for a track car I think the BEC makes more sense. The point about price with regard to the exhaust is well taken, and I think also there is usually some other hardware (read money) to make the BEC happen (especially if you want, or need, reverse).

You can't drive on the road without a reverse gear, so with a bike-engined car, allow another £600-800 for a reverse gearbox attachment (Quaife make one).

Also don't forget to include the cost of the IVA test in your budget (around £450)

Regards

[The Black Flash]

guy_spyder550 said:

Been vaguely looking at building a Dax Rush myself. The idea of a turboed Rush does appeal, but as FurybladeLee says a few posts back a torque surge mid-bend can make things unexpectedly interesting. Thus looking at the possibilty of the Quadra version of the Rush. From what I recall these used the the 4wd Sierra drivetrain, which I guess now are as common as finding an MP who hasn't milked the expense system.

Edited by guy_spyder550 on Friday 30th October 00:07

Have a chat on the owners club - several turbo owners there who track their cars, so they should be able to say for sure.

Plenty of 4x4 sierras still breaking at the moment, they're popular for use in 2wd applications as they had an LSD as standard. I got parts from one for my build just last year, without difficulty.

[The Black Flash]

gingerpaul said:

It's all been said already but I will agree with those who think a bike engine is the way for you to go judging by your intended use. The S2000 appears to be a good and proven choice now too though.

Cost a lot more than a thousand quid though, now that breakers have cottoned on to their popularity for kits

[kennyrayandersen]

pilbeam_mp62 said:

kennyrayandersen said:

I’d rather have one that I could drive more on the road, so for me I don’t want all that screaming waah, waah, waah going on, but for a track car I think the BEC makes more sense. The point about price with regard to the exhaust is well taken, and I think also there is usually some other hardware (read money) to make the BEC happen (especially if you want, or need, reverse).

You can't drive on the road without a reverse gear, so with a bike-engined car, allow another £600-800 for a reverse gearbox attachment (Quaife make one).

Also don't forget to include the cost of the IVA test in your budget (around £450)

Regards

We don't need no stinking reverse in the USA -- live free or die -- don't tread on me (and all that). OK, California sucks (for car mods anyway) but the other 49 are OK lol