My 200mph budget build

[pzr vr6]

That was one of the first things i did ask about when i thought about tyre sizes etc.

I was more thinking about the centrifugal forces makes the tyre expand beyond its 'natural' size.

When speaking to Rod about it, he said when calculating his stack dash off gears and cold 35psi tyre size he ended up still being close, ie at 200mph his stackdash was 1mph out.

So he believes there is a very small amount of expansion but not enough to add it into the equation.

Accelarating from 60-120 will cause a small increase in tyre pressure due to heat of friction and a little bit of wheelspin but then will equalise after this point.

The issue you see on a rolling road is infact the car wanting to wheelspin in the rollers for the entire run, this will generate heat and cause the tyre expansion, ie you can wheelspin a car on the rollers in 4th but not on the road at the same rpm.

Ill be using toyo 888s as this will give me better traction out of the corner onto the straight and have been proven to run at 210mph safely



glad to be of help, any questions you wanna ask about anything mechanical on rotary or piston ask away

r888s are great BUT they wont help your top speed at all mate you get a lot more rolling friction from sticky tyres than normal tyres

 

[K1LLSW1TCH]

Great thread! I skipped a few pages of the bickering but I'm going to subscribe to this.


Best of luck!

 

[turbotoaster]

r888s are great BUT they wont help your top speed at all mate you get a lot more rolling friction from sticky tyres than normal tyres

the reason im going for them is two fold.

I know they have been taken over 200mph a few times by different tuners.

since this is rwd and im gonna try and put 700bhp to the tarmac coming out of the corner i want to keep my speed as high as possible, so the more grip i have the faster i can corner.

I understand softer compound tyres cause more friction, thats the point of them, but i never claim to be a driving god and these will make my life easier trying to get out of that corner without the rear overtaking the front.

oh yeh i went to that rolling road day at psi.....i left after an hour, dear me there was more fun atmosphere at a funeral!!
you couldnt watch the runs properly as they put the big shutter down and we all had to stand outside when it was minus 4, not fun

 

[Fett]

since this is rwd and im gonna try and put 700bhp to the tarmac coming out of the corner i want to keep my speed as high as possible, so the more grip i have the faster i can corner.
(

Why are you using the corner? With what you will be running hopefully, I would have thought you'll be better off from a standing start, unless you are concerned about clutch issues. It's give or take ~5mph but that is dependant on your line and how well your car can stick it all down. If you've not done this before and you have limited runs, it wouldn't hurt to consider it and removes having to balance 700bhp on concrete.

 

[turbotoaster]

the problem is cost im afraid.

im going to be running a standard auto diff which with a standing start will destroy itself with that much power.

You cant get a uprated diff with a 3.9 ratio, only 4.1 plus.

the only option then would be to go with a american v8 9" rear diff and pay to have all that fitted which will cost a fortune.

If i were to fit that id probably snap the driveshafts on launch so id need to pay another 400 for stronger shafts.

There just isnt the money really for standing start runs.

Ill be coming around the corner in third gear, probably at about 70-80mph, which will take a lot of pressure off the backend as it will already be loaded up.

Ill get there early and do a few practice runs at the corner, ie increase my cornering in 5mph intervals to find out where the limit is, then do a run at that speed and follow it on down the straight to get a low top speed in(say 170-180)

Once ive done that i can concerntrate on getting my braking points at the end of the straight sorted, then just a case of combining it all together and hopefully jobs a good one

if i was running a different rear end id just launch it down the straight hard and do 200mph in one run, have a bacon sarnie and then go home lol

 

[pzr vr6]

i only went to psi to drop my controller off saw my car looking sulky in the far corner and left lol

why would you want to start fom 0 mph when you could get a rolling start with the same distance?

 

[turbotoaster]

this is just a quick sketch to give you an idea of what happens there.

You have a choice on which route you take, as you can see its harder to keep the speed up and accelarate in a rwd car coming out of the corner as it will want to drift.

You can choose the other option of launching from where i marked '0mph' and all you have to do is keep the car straight which is a lot easier, but then you put a lot more pressure on the diff/driveshafts.

If this was a 4wd or fwd car then the corner route would be a lot easier

 

[D.Roberts]

realy nice work there maty loving it.

just a Q if i may

the pic you compare the two ports stock and then ported was that a shot of the inlet port? dont get me wrong you know what you is doing I was just all ways aware that Inlet ports look good all blingy but they dont work as well due to the fuel not atomising instead on a shiny port the fuel just forms in droplets on the surface.

any who great work.

 

[turbotoaster]

realy nice work there maty loving it.

just a Q if i may

the pic you compare the two ports stock and then ported was that a shot of the inlet port? dont get me wrong you know what you is doing I was just all ways aware that Inlet ports look good all blingy but they dont work as well due to the fuel not atomising instead on a shiny port the fuel just forms in droplets on the surface.

any who great work.

ah im guessing your looking at the pic on page 2 where its all nice and shiny.

That pic is actually a reference picture i took from a website in america to show the difference in size as i thought that pic was easy for everyone to see.

My ports are the nearly same 'roughness' as stock ports, just a lot bigger, on page 6 you can see my templates i made to do the porting, thats probably an easier way to look at the size, but yeh, i know about shiny ports and didnt go down that route you dont need to worry

though im gonna be putting around 6000cc/min at peak power so id imagine theres only so much that could possibly stick lol

 

[86JR]

Why cant you just do like, 50mph round that corner and then aim more towards the end of the runway so the turn isnt as tight and just got WOT ? I cant see you being able to go WOT on the corner without the back end coming out.

I take it "Rod" is the 200mph sapphire cosworth owner ?

 

[turbotoaster]

yeh thats rod, im only going off what he and mark shead do when they are attempting run, also thats the same as the 700bhp 911 that did 211mph down there, he follows the same line from trying different things in the past.

I can only assume they are right as ive never attempted it myself and with the large amount of attempts they both have had.

if i were to take the corner slower and stay more to the left of the picture(i assume thats what you mean) it means i have to be at full throttle at a lower speed, which then means i have to try and put 700bhp down in second instead of third which is most likely to wheelspin and cause my diff to break from wheel hop.

I think its easier to hit the corner at a higher speed then hit the throttle less, saying that, watching the video of mark in the car he is full throttle in third from about halfway between the 70mph and 80mph markers on my picture and changes from 3rd to 4th at about my 100mph marker but he will be doing more like 120-125mph.

I know my car will corner better than his as i have better suspension and wider tyres, so i should be able to match him at the 120mph, its just then his extra 200bhp comes in and he buggers off

http://www.youtube.com/watch?v=O9-UF1_1LQE

watch from from 3:00 onwards to see what i mean

 

[86JR]

Yup, your correct, although he does say he only saves about a second of acceleration doing so (im on pf too).

my friend on there (Chip) says you should easily achieve your target with around 700 brake

 

[pzr vr6]

this is just a quick sketch to give you an idea of what happens there.

You have a choice on which route you take, as you can see its harder to keep the speed up and accelarate in a rwd car coming out of the corner as it will want to drift.

You can choose the other option of launching from where i marked '0mph' and all you have to do is keep the car straight which is a lot easier, but then you put a lot more pressure on the diff/driveshafts.

If this was a 4wd or fwd car then the corner route would be a lot easier

just looking at thaty pic suggests to me the apex should be later than it shows that way you get a straighter line onto the straight allowing for more throttle

 

[~>Dg<~]

funny enough we was on about that guys cossie last night a bunch of us were suggesting cars that could do it and we were watching his video that was on fifth gear .

how much did it take for his engine and mods though ?

 

[turbotoaster]

just looking at thaty pic suggests to me the apex should be later than it shows that way you get a straighter line onto the straight allowing for more throttle

im a much better with a pencil and paper than i am with paint so just tried to pull the line to a rough curve, i know that not the exact line, it was more to show that other guy what i meant about the corner, ill be following the cossie line much closer than my 2 secs doodle lol

funny enough we was on about that guys cossie last night a bunch of us were suggesting cars that could do it and we were watching his video that was on fifth gear .

how much did it take for his engine and mods though ?

Well i think last time it did a top speed run it was up to 40k plus the car, but that car has been through many evolutions and has the best of everything, hes also going for 215mph this year with a 1000bhp so way out of my leaque, probably closer to 50k plus the car.

the one of 5th gear you watched was 700bhp engine +150shot of nos i believe

 

[D.Roberts]

"though im gonna be putting around 6000cc/min at peak power so id imagine theres only so much that could possibly stick lol "

hehehehe very true like i said you know what you is doing i was just shocked after all the work you are doing to see such a noob mistake im glad you havent.

good luck and please be safe out there.

 

[turbotoaster]

my new intercooler arrived today so i thought id chuck some pics up.

Now originally i had decided to go with a 70mm thick rs500 intercooler, the reason for this is that it would fit pretty well into the enginebay and is known to flow well for 700bhp.

When i was chatting to my manifold guy on msn he mentioned inlet/outlet sizes, i said well the standard cossie is 2.5inch throttle body and the rs500 was 3inch from what i had been told, so if its aimed at the 700bhp market then it will have 3inch pipes(it didnt say on the website) He recommended i check with them just incase.

I emailed them and they confirmed that they were infact only 2.5inch......since the outlet of my turbo is already being reduced from 3.5in to 3inch i didnt want to go down in size again, asking how much it would be to cut them off and weld in 3in he said £60-80, which would take the price of the cooler up to £370 which in my eyes was to much as i would have to make savings somewhere else to hit budget.

So then i looked at other options and come across this cooler i now have recieved.

They retail at £180 on ebay but luckily they had on that was on auction, with a bid of sniping i got it for £72!! Now i again need some work doing to it but its a big saving over the other cooler

the core is 600mmx290mmx120mm...yep its a thick one.

it has a larger overall capacity than the 70mm cooler and ive seen it push 900bhp in america so hopefully it will do the job for me.

big box arrives this morning!

woohoo, no damage anywhere

its rather thick

its also rather bloody heavy!

put in hot water for 10mins to test for any air leaks, seems fine

compared to standard cooler

now just need to do some measurements to compare it on the car to see what needs to be modded to fit

 

[Malt_Vinegar]

Whats the weight like compared to the original unit?

 

[turbotoaster]

not 100% sure, the original weighs about 3kg max i would say.

the car wil have a lot of its weight altered, the big intercooler, larger rad, massive turbo, 2 large fuel pumps.

there will be little savings like a side exit but im thinking the car is now 1220kg, it will be closer to 1300kg when its finished and i dont really want to strip the car out as i like it comfy as it is, i may install lighter bucket seats but that will be after the top speed run


and im trying to avoid putting it into the bumper as it means longer pipework, its a big cooler and big turbo so i want to minimize distance the air has to travel if i can.

due to the size of the cooler it seems there space i have in the engine bay is where the battery box starts and also where it ends which is 266mm

the cooler is 120mm, rad is 73mm and id say the fans are 60mm but if anyone can confirm there width for me that would be brilliant....thats 253mm so im cutting it fine.

here is an idea, what do you think

since the cooler shape means at its widest it will be around 810mm(where the inlets would be welded) there are other areas where is narrower, so it could be mounted completely flat and one end me closer to the front of the car as its only 290mm in height so at worst i could mount it in a vmount configuration, but then ill need to look at bonnets because i dont believe i can but 2bar of boost through it and it have no path to release the hot air

 

[Dup]

How's this going?

Just remembered this thread. I've suddenly devloped a lust for an FD3S, so that's what I'm gonna start saving for. I won't be throwing thousands at a 200mph build mind you!