39 replies to this topic

[Rhys]

Ok everyone, after our last chat about my £2000 engine budget i have reconsidered my options. I have been looking into the Jon Speed supercharger kits.

With a 2k budget is it possible to get good power from one of these kits and what spec would you recommend? I want around 100 bananas at the wheels but i will settle for 100 at the fly if its not achievable.

What are the downsides of the supercharged option?

Rhys

Edited by Rhys, 13 June 2008 - 02:07 PM.

[mini23]

Should have bought my kit that sold a few days ago on ebay for £720

Complete kit just need a head, cam and high lift rockers for over 140bhp at the flywheel.

I have another to go on ebay in a few weeks just have to buy a 45 dcoe carb and jet it.

Mines been 100% reliable running up to 225bhp with nos at santa pod last year.

The down side is fuel consumption, even the mpi's are only getting low 20's to the gallon, its just the nature of the charger.

You will need a crosspin diff as an absolute minimum

[Sam Walters]

get a turbo instead, fuel economy will be slightly better as your not contstantly on boost like a super charger hence no un needed fuel is being kicked through.

admitadly a super charger is more progressive then a turbo however if your spooling that turbo youll be between 2800 and 7000revs depending on the turbo you go for.

[Rhys]

Are superchargers not better for all round driveability?

Been looking on the Jon Speed site and they use the HIF44 is that not a good choice?

Is it all possible for 2k bearing in mind i have no engine at all so far.

Rhys

Edited by Rhys, 13 June 2008 - 03:24 PM.

[Rhys]

Also which kit is the best to go for 1, 2 or 3?

Rhys

[smith1380gt]

I have a stock A+ bottom end and gearbox with an Avonbar 26cc head and eaton 45 Jonspeed kit with HIF44 carb. Low end and midrange torque is amazing, power falls off above 6000 or so. 110Hp at the wheels with a slipping standard verto clutch (need to upgrade).

Longevity with a suck thru setup like Jonspeed and vmax is an issue, as the teflon coating on the lobes of the Eaton will remove itself over time with exposure to petrol. Not sure how long it wil last, but I figure for 150 GBP I can get another off of Ebay. For ultimate power and tuneability, I think turbo is the better option, but you have to be willing to cut a hole in your bulkhead.

I will also repeat the Fuel economy issue of the supercharger. I figure I'm getting about 18mpg at best. But I am putting my foot to it a lot...

[Wil_h]

Mines been 100% reliable running up to 225bhp with nos at santa pod last year.

Wow I never knew that, I should have paid more attention, what's your ET than?

You should easily achieve your target with an SC, but IMO look at the Vmax kit rather than the Jonspeed. And for the money I'd buy a mirage manifold and stick a T2 on. Almost SC like low-down power plus more total power and fuel economy too.

[Rhys]

So then will you would go for the mirage manifold kit? do the turbos take long to warm up? Also do you get the same kind of power from the mirage?

Rhys

[Turbo Phil]

The Mirage manifold design may not look optimal, but the fastest 5 port Turbo mini in the country uses one so it can't be to bad.

[Rhys]

As i say im not looking for mental power like 120 at the fly, possible with 2k?

How much better is the fuel economy?

Rhys

[Sam Walters]

your not going for hugh power so you dont need too low a compression ratio.



personally i would take a goodish condition mg metro engine get something like a stage 2 head with the standard chamber sizes.
and get the mirage manifolds.

while the engine is out put a molychromed 4 pin diff on it.


basicly that engine there. will give you slightly lower fuel economy then the standard engine if you keep off the boost but its marginal.

and 120-150 at the fly if you turn up the boost, i suggest you put an intercooler on it. improves power while enableing you to keep the boost down.

and youll have lots of money still left in your hand.


if you source all your bits carefully you could proably do it for 800 or even less.

Edited by flyingears2002, 14 June 2008 - 01:17 PM.

[Rhys]

That is mental, i was thinking of having a stage 4 head would that make much of a difference?

I want 120 at the fly constantly really and 150 on standby if i wanted to. Dont worry to much about fuel i can always change the setup if it bothers me too much. What kind of psi will i need to run?

Rhys

Edited by Rhys, 14 June 2008 - 01:24 PM.

[johnnysti]

Well im running a 1380 MED with a vmax weber kit doing just over 155BHP and getting 12 miles to the gallon, no matter how i drive!! The only thing i would say that if cost is an issue its not worth doing. You really will need the best of what is available to get the life out of the car. And i only use it now and then.

Johnny

[Rhys]

12 miles to the gallon! That is ridiculous, if cost is an issue you would not bother...how do you get anything done without spending stupid money. I have to have a budget and a time frame to make sure its possible. Until i win the lottery i have no choice but to worry

[Sam Walters]

get the chambers ground back to normall size with the stage 4 head and put on a mg metro engine.

to get power from little boost you need a good flowing head. goodish bottom end and pistons ect and an inter cooler, and that cross diff i talked about and keep the compression relitivly high eg standard.

the problem with superchargers is that its constantly on boost even when you dont need it like sitting on the motor way at 55mph.

a turbo charger comes on boost when it has enough pressure.

12-14 psi will bag you that 120 at the fly.


my turbo build will be running at nearly 30 psi. trying to hit 200bhp.