Hi folks, welll this is aimed more at the tuners really, but I welcome anyones USEFUL input I have been collecting bits now for a few years to build up my sapphire cossies engine, and my spec is as follows

200 .5 overbore long-studded( centre 6 ) block, std crank ( std and std )
arrow H section std length con rods
75 psi oil pump
High compression 8.5-1 JE forged racing pistons
3 Layer steel head gasket
Touring car spec head ( massive ports/knife edged etc)
BD 16 inlet cam with special single springs
BD14 inlet cam , both with vernier pulleys
GT 35 turbo with turbonetics external wastegate
WRC 8 injector inlet plenum with T25 cover plate (one peice elbow) and ALS set up throttle body
8x803 injectors and a P8 with an 8 injector board+ ALS board, water injection controller etc.
Air injectors
STD 2wd exhast manifoldmanifold (which will be modded/replaced to suit the GT35)
all the ancills ( 500 cooler, swirl pot etc) to put it in the bay happily

Now, im a bit worried about this being a mis-matched spec, but I was aiming for a solid 500+bhp and 500 Lbs of torque, with the high comp keeping it drivable. Is this going to work or will I have to modify this radically to make a decent package? Any info would be greatly appreciated as I am getting worried now and need to finalize this or its going to keep snowballing

 

Dude the compression seems very high?Seems a good spec tho mate

 

The high comp was so it was drivable, hence forged pistons to take the extra stress, I don't want a lag monster thats horrible to drive off boost. Hopefully it won't cause too many problems, I was wondering if this can be mapped around?

 

just go 7.5.1 mate its a good comprmise and ul get the figure of 500 easy id expect.Maybe u should drive a car with a lower compression see how bad it is??As for lag people said to me on here its more cam selection rather than compression.I think mike r has a very nicly setup 500 bhp car

 

driven a low comp cossie, infact i got another one , its 7.7-1 and running 2x BD14's, its not too bad but I wouldn't want it any lower Cams is one of my other main concerns so I will have to see what people reccomend

 

Found a GT35 yet?

 

Thats hardly low comp is it lol low comp being 7.2.1 really isnt it.My advice to u is ask the engine builder lol and tell him what u want out of it.U will get a diff opinyon of every body on here if any opinyon at all.Go with one guy and listin to him not a mix up of lotts of ideas

 

"special single springs"

 

Yea u proberly are better of with iskys

 

I think the 8.5:1 is gonna be the problem if you want big power on pump fuel.

TBH ive never really noticed the difference off boost between low and high comp cars, not when mapped right.

Its the big ports and big cams that will fuck drivability, not a slightly lower compression.

What exhaust housing size you using?

 

Nice spec....and 500bhp is the limit on that comp ratio providing you got a good mapper....will drive lovely and make good torque..BUT bare in mind longevity will be the issue as a .5 200 block aint gonna last long with the forces created with that comp ratio...you NEED liners at a bare minimum as these are stronger than the original block or preferbly the proper nikasil block.......my engine is 7.9-1 running liners on the eec4 block long studded WRC gasket etc...aiming for 600bhp on a GT35.

 

The compression is open to debate, How are you going to map it and varify the HP/Tq as 500hp quite easy but likely only 420ftlb.

Mark

 

Is the '3 layer gasket' up to the job?

the daddy mountune one is a 4 layer i think

 

and a pukka mapping session - and i mean pukka, will see exactly what you want pal, and will be a beast

if i was going for that sort of power , i would be probably in that range or spec, especially with that comp ratio

 

I thought you couldn't run ALS with the GT series turbos ?

 

...to add forget anti lag the GT series wont last long with it!

 

to be honoust i know nothing about anti lag and the ball bearing turbos, but from what ive seen of the bb turbos there no where near as resiliant and the wet core floating type

 

To be honest, its 99.5% that Stu is going to get the mapping work,having seen his work on my mates cars, its worth the 2-3hr drive up to him from brum

I have been told that the GT35 will take ALS quite happily, so that will be a suck it and see sorta thing I suppose. I take it running ALS that closed loop lamda won't be an option due to melting the poor sensor , but to be honest its going to be a play car anyway so im not really that bothered about MPG etc.

I already have all the parts I have mentioned in my spec at the top, the only things I have left to get is a decent baffled/gated sump, a decent exhaust manifold ( maybe tubular, I think I read somthing about simpson race exhausts doing made to spec ones for a sensible price?) and maybe a R'n'B inlet plenum. The Nikasil linered block would be nice, but at Ł1400 it can wait until I am due a rebuild again

As regards the 6 studs in the block, do you have to modify the water pump to clear the front studs if you go for 10?
I take it running 8 injectors is not a problem except for the fact that if you do loose one, you get a lean cylinder rarther than a total misfire? I would go for 4x1000cc's, but I already have the P8 with an 8 injector board, so it seems a shame to sell it, as it has all the ALS boards in as well, and I don't think I would get anywhere near what I paid for it back

I don't mind changing major bits to sort it out, and as regards to the comp ratio, would a slightly thicker copper head gasket be a suitable cure if needed, or would it fook the squish up too much?

Besides, all this is Broms fault , If I had never been in his sapphire and experienced warp drive, I would have been quite happy with 400 BHP

Any more input/suggestions welcome

 

My small input william, Hurry the fuck up and do something with it as 4 years is a long time building it!!

steve

 

anything else SENSIBLE please??

 

upski

 

See above, And my car will probably need a rebuild in a coulple of years before your engine gets built or put into anything ya cheeky fucker

steve

 

GET MSN YOU FOOKING GOON goddam ste get with the modern world

 

Just hurry up and get back home ya lazy scroungin tosspot!
bout time you got a proper job!!!!
Modern world
i got a pooter now and a t.v.

steve

 

ah but have you got a washing machine yet?>?>

 

Yeah course i have what do you think the microwaves on Had it over 2 years now just aint plumbed in yet

 

You are going to need to keep torque to a minimum on that CR, so the only way you are going to see big power is lots of rpm.

Cant see anything there to stop you running 8500rpm though potentially if you go onto sollid lifters (and hence solid cams obviously), so possibly you can pull that off, the devil is in the detail though of course, but im sure Stu can get the best from it.

Certainly be interesting to see a dyno plot when its done.

If it was me though, i would go lower CR to be honest, its going to be shite at low rpm with a massive head and those cams anyway, so why bother what its like off boost, just drive it making sure you are always in the right gear to be on boost when you want to accelerate!

 

Exactly

Its basically what i said/meant but said much better

 

RWD_cossie_wil
nice pic in your sig!!

 

cheers its the aircraft I work on in the RAF , Thats called the hercules angel, made by the defensive flares which protect the aircraft from missiles etc

 

I would basically echo Chips reply to be honest Will..

That cam combination is going to destroy driveability anyway, compression wont help it at all really.

I would also personally drop the 8 injectors, runners, 8inj loom and the P8, sell it for the huge amount of cash they draw, and fit 4 big injectors and a level 8, get it live mapped on closed loop and still have a LOT of change from your sale.

 

I'd think about a smaller Turbo as well... what about an internal gated GT30 if you only want 500bhp?

 

Blimey, i missed the power requirement bit, sorry

 

You will either have to limit the boost to around 1.2 - 1.5 bar or run HUGE ignition retard (which will kill the turbo / manifold / exhaust valves) at that compression. You will also need a relatively big exhaust housing to keep the cylinder pressures down, which will go against what you are trying to achieve with the high comp in the first place . Seems a mismatch, unless you intend running it on rocket fuel most of the time?

 

I'm trying to work out if that is actually a very good answer OR a load of mis-guided bollox