Just a quick question guys. Would it be possible to build a 2.5 that could reliably handle 550-600bhp? Im thinking of doing a build over a year or so, would this be achieveable? Obviously be doing gearbox,brakes,suspension etc to cope

 

RCM Gobstopper.

As far as im aware that car has run circa 800bhp for over 3 seasons now without a rebuild.

Someone may correct me if im wrong.

Id say its do-able, speak to teh guys at Area52 Autosport for bombproof big bhp builds. They did a WR1 made to reliably run 550bhp in cyprus on pump gas.

 

Frayz the RCMS car, although a wonderful feet of engineering, is not a 2.5

Has the Area52 car secured any points in the Time Attack; surely the proving ground for any tuning company?
My car runs close to 480ftlbs on the road yet this has to be lowered to less than 400ftlbs for sustained track use (with STi TIMC), I can happily make the numbers for a one off dyno print out with the T. Didn't Andy claim 600ftlbs at one point, no doubt achieveble, but sustainable?

 

Sorry, i missed the 2.5 part. Yes the RCM gobstopper is a 2.35 AFAIK.

He didnt say he wanted to compete in it. He said he wanted a bhp figure that was reliable mate. IMO a car running that sort of power to be used as a DD in Cyprus on pump gas is a pretty good testament to the build.

Maybe if the OP clarifies what he/she intends to use the car for, their questions maybe easier to answer more accurately.

 

Afaik the gobstopper is still a 2 litre engine.

Banny

 

RCM dont recomend over 2 litre for big hp We are going for a 600 hp build and are using a 2 litre block, filled with RCMS parts,
there are so many experts with so many oppinions, none of them wrong ,just arrived at through personal experience,
so its up to you who you beleive, but for me the RCM gobstopper is a testiment to sound engineering, I chose to follow their advise,

 

Why do you want 550-600 bhp?

Are you going for competition of some sort, or is it to be a road car, or do you just want to brag about power figures down the pub...?

If you want a quick road car, go the 2.5 route, with 450-500 ish of both power and torque.

For competition stick with 2.0/2.2 CDB plus usual internals...

Just my 2 pence worth.

 

In a word yes,
I'm part way through doing just the thing.
Start with a closed deck 2.0L Block
Have it bored and sleeved to 2.5.
Here's some pics of the work in progress

Top Hat Steel liners
Here's the engineers diagram of the liners


The Block itself




It's got these rods and pistons inside

 

The car is going to be mainly used as a weekend play thing and the odd track day. But if it could be made reliable at about 500-550bhp i would be more than happy

 

I say fair play, a chap on the forum I am apart of has his Scooby very close to 600bhp, Its his toy and track car.

Quality build and all the mod cons, as at that bhp Traction is a major factor

 

mine is igetting a 2.5 transplant at the mo and they say its going to have 530bhp and over 550ftlbs or even more now they have decided to do a twisted turbo.
they reasure me its going to be totaly realiable.
and the original gearbox can take over 650bhp.
so yes it will take that power

 

Have they sleeved the 2.5 block?

 

Would be suprised if the original gearbox will take that sort of torque

 

Me too. Im going for either a PPG kit or if i save up for a bit longer maybe a Quaife sequential

 

If it is a 6 speed gearbox then it should handle that power, as that is what the Zen car runs.

Banny

 

Don't under estimate how much difference a light weight car makes to reducing stress on parts such as clutch, and gearbox.


Dazza,

I'll be interested to see how those liners work out, because I'm a little concerned that a 1.3mm lip to the flange may be a little on the small side.


Mark.

 

The chap that's done them (from a local engineering firm) Has assured me they wont move.
He's a 68 year old bloke that's been an engineer since he was 15. Hopefully he's speeking from experience.
But I'm fully aware just because someone's been doing something a long time doesn't mean they are any good at it

I guess time will tell.
Incedently Mark I don't suppose you have details of STI V 5 cam profiles/dimensions so I can get these verniers set up do you?

Cheers

Dazza

 

Dazza,


When it comes to Subaru's, the only experience worth anything is how many Subaru blocks has he re-linered, that are running 550bhp +, where the liners haven't dropped ?

Nothing else really matters ! But I hope his experience in steam engines works on our engines too ;-)

Sorry, I don't have the cam spec's, but start with 110/110 deg', and work from there.


Mark.

 

All too true Mark, he builds alot of big power American Drag engines apparently.
I know mine was the first 2.0L CDB Subaru Block he's relinered to 2.5 though.

If it does fail then he'll be getting the bugger back. It cost me £1200 to get it done. He's a smashing fella though and always gives me advice whether i've asked for it or not lol.

Cheers for the info on the Cams.

 

big power american drag race engines
Something I know quiet a bit about and I know a linered block is something to avoid like the plauge for serious power
Unless its a KB or BAE block with liners that are designed to be changed quickly and these are ally billet blocks mostly,
and the liners are Made by the block manufacturers and cost about $100 each
Just as in the scooby world there are engine builders and engine builders say no more

 

Everyones an expert it seems.

I didn't say they relinered their drag engines I just said they built them.
Incedently my liners cost around £100 GBP each.

The whole relinering job cost me £1200. He's confident they'll be fine. So I'm happy

 

gosh

 

As far as drag racing goes yes i am,
2 national championship wins back to back,
currently # three in the RAC MSA Pro Mod series,
and a 2500 bhp blown alchohol motor that I assemble,
off thread i know but i DO know about big hp engines and i AM a drag racing Expert if thats the word you like to use, I prefer champion.....

 

I was in a simular situation this time nearly 2 years ago

things have swapped and changed about so much but In the end I went for a 2.5. Im not chasing figures I just want a fast road car

RCM are building,

i want as little lag as possible with as bigger power band as possible

I am hoping if i have made the right choice the car will feel plenty fast enough for the road

why do you think you want 550 \ 600 bhp ?

Rich

 

Basically i want to have a bit of fun for a year or so then possibly look at competeing in a Hillclimb championship.

 

pick a good supplier and talk to them, if your looking at motorsport you could do allot worse than RCM - remember they can take over a year to get things sorted

many people start these threads not many compleate

there is a p1 knocking around that had a simular scope and Im sure he said he had spent over 50k

Rich

 

LOL and you were on here asking advice about fuel pumps?

Of course you are the drag building supremo you profess to be
or should that be drag queen lololol

 

yeah i asked about fuel pumps I actualy asked what was the biggest pump that would fit inside a scooby tank thats scooby related Hardly drag racing related is it???
Drag queen??? i wish i was that good looking



thats a fuel pump

 

I'm not being funny mate but that looks Radio controlled car size.

I'm sure it's not and I'm sure its the real deal but it just made me giggle a bit when you look at in proportion to the fence behind it.

Incedently I'm a dab hand with Accuracy International Rifles but that had nothing to do with linering subaru engines so didn't feel the need to mention it lol

 

Has this turned in to a thread about drag racing?