Piper do charge around £120 last time i had one sent away..Originally Posted by Mart
Piper do charge around £120 last time i had one sent away..
Yeah, thanks all the same, but it's time to move on and up the power. I'm not looking to "out doing people" on here. Why would I?
- Like has been said a new turbo will make you feel alot more power that on stock t2 or what ever you have.
- Why would you ?: every human wants more/better or most do.
I don't even know anyone on here and to be honest, there's always someone out there faster, minter, better, anyway.... and fair play to them. I don't quite know how you've come to this assumption....
- Theres no fast gtt engine than the one in links that i posted
- your asking how far to go b4 its a joke and re -build after rebuild is needed
people say and you still want 250hp when peeps have said it become hard after 230hp not to lose bolts
Can I not just find the tolerances and options of tuning my engine without people telling me what I should do?[/quote]
your asking people to tell you what to do ! rather than a like a few of the tech posters in this topic have done. spend years/ time /money /sweat and shed tears. in finding what is the best, most affective way to tune with out wastin money
dont take me the wrong way am just trying to help you find what route to go now.
ai
Last edited by dave j gtt; 18-11-2009 at 22:41.
i was a newbie when it disapeared, RIP old rtoc site
I disagree. There's a lot of people out there who also wouldn't give a flying fook what people (who they don't know) are doing with their cars.
No offence, but I didn't check the link until now. You can guess why, right?- Theres no fast gtt engine than the one in links that i posted
From what I've gathered, the main focus is the tune with the C1J. This going to be my main priority once the engine is together.... now, while I choose the internals and the bolt on bits, don't you think it's a good idea to aim high?.... as, when it's actually running, it'll be gradually tuned and carefully taken up to a safe limit. Where this is limit is I have no idea at this stage, but at least there won't become a point where I'm regretting not choosing the bit's needed for that tune.- your asking how far to go b4 its a joke and re -build after rebuild is needed
people say and you still want 250hp when peeps have said it become hard after 230hp not to lose bolts
No I'm not. I'm asking for 'advice'.your asking people to tell you what to do !
Are you suggesting that I have wasted money?rather than a like a few of the tech posters in this topic have done. spend years/ time /money /sweat and shed tears. in finding what is the best, most affective way to tune with out wastin money
Yeah sure, if you've got any more constuctive posts, fire away.dont take me the wrong way am just trying to help you find what route to go now.
ai
It's (nearly) always interesting to read these types threads so I'm not knocking it, but I think the advice from most people would be similar to the first reply posted (which was in May!). It went something like this:
Standard piston and liners
Standard carb (not a group A)
Decent intecooler
T25 or T28 turbo
AFR gauge of some sort
Cam (Piper 285 or CatCams 5500327 with appropriate valve springs)
1.5bar MAP
Before you go searching for 250+bhp (and all of the associated expense and driveability problems this will bring) try the above.
Invest all your research time in learning how to tune the carb and detect knock; if you do this well then you'll have a very quick car that won't let you down (much).
Thats about standard boost then
I'm sure the original postee ment to say manifold pressure
No, I made that mistake all by myself :-)Thats about standard boost then
I'm sure the original postee ment to say manifold pressure
I still say 250hp out of a c1j is gonna bring a whole world of pain & unreliabilty. Anywhere bar a drag strip & that much power isn't gonna be useable to its full potential anyway, but each to their own & good luck with the build
Have to agree with Mart on this one, having had a car pushing around 220bhp as a road/drag car it takes a fair bit of doing keeping an eye on everything, I had an AFR gauge, EGT gauge, oil pressure gauge, boost gauge... you get the idea & then there's the hours of tuning the fecking carb to run the boost, had it fueling for 24psi manifold but it still started to lean out @ 6k.... It's all ok but it starts to become your life .lol. My wife, my poor, poor wife..
Still I'd do it all again though
Just get a honda tho instead steStill I'd do it all again though
I know this may upset the hardcore gtt fans but if you want that much power why not bin the c1j and do what others have done and fit something bigger with a better flowing head, no 25mm restrictor and no weak valve train. Even the trusty valver motor at pony boost will make what power you want with a lot more reliability.
i'll be right....
Just get a honda tho instead ste
Yeah Rob, for sure, something else with liners to crack
I'm just setting down the foundations for big power at the moment.... if the tune is good, who knows where I'll get, but I either way, I don't intend to push beyond the limit.I still say 250hp out of a c1j is gonna bring a whole world of pain & unreliabilty. Anywhere bar a drag strip & that much power isn't gonna be useable to its full potential anyway, but each to their own & good luck with the build
Any volunteers for drilling my jets once it's running? I'll make sure your time is worth while.
I'm just setting down the foundations for big power at the moment.... if the tune is good, who knows where I'll get, but I either way, I don't intend to push beyond the limit.
Any volunteers for drilling my jets once it's running? I'll make sure your time is worth while.
go for 200bhp an just give it death !!
anymore an you will hit some niggly issues..like POP !!!
more would be ok i think if you doing the 1/4 mile but for
general use an abuse it will not last to long with out problems.
There stronger than most peeps think the stock honda sleeves, a good few peeps making big HP with stock sleeves... We had to break ours simiply to find our limitsYeah Rob, for sure, something else with liners to crack
I'm just setting down the foundations for big power at the moment.... if the tune is good, who knows where I'll get, but I either way, I don't intend to push beyond the limit.
Any volunteers for drilling my jets once it's running? I'll make sure your time is worth while.
I dont mind lending a hand providing you have wide band, if I were you I would take the carb body to a local engineering firm and have the second stage bush machined out to accept an a.c jet.
Thanks mate, appreciated.
I'm going to keep an eye out for a second hand standard carb. When I get one, could you recommend me someone to do that?
It couldn't have been much less (if at all) on the previous set up. Not that I am complaining.
Yeah, I'm certainly going to take extra care with taking the power up.... regarding general use and abuse... I tend to drive like an old man 80% of the time and the other 20% is just general grins and p!sssing off the big guns who pull up next to me in their Type R's/BMW's. It's especially pleasing when they have their girlfriends in the car.anymore an you will hit some niggly issues..like POP !!!
more would be ok i think if you doing the 1/4 mile but for
general use an abuse it will not last to long with out problems.
Just got off the phone to a J.E piston supplier and they want to know what spec I would need the forged pistons (as they're apparently custom)? He also mentioned that the standard compression (7.9 to 1) was too low?
I'm sending them one of my old pistons as a sample, but to be clear, all I want is standard compression, bore size and valve seats?
Cheers
7.9:1 is standard.......
Thats standard compression mate, as you say send him a standard piston and ask for it to be copied.Just got off the phone to a J.E piston supplier and they want to know what spec I would need the forged pistons (as they're apparently custom)? He also mentioned that the standard compression (7.9 to 1) was too low?
I'm sending them one of my old pistons as a sample, but to be clear, all I want is standard compression, bore size and valve seats?
Cheers
Yep.
He mentioned this standard compression was too low and that if these pistons were going in his engine he would up the compression.
Just wanted to run this through you guys....
Well I personally wouldn't be doing that.
Cool... will do. Just wasn't sure why he thought the standard compression was too low.
Cheers.
Yeah, I thought it was a bit strange. The head gasket is going be under enough strain as it is.
I would!
I'd probably go for flat topped pistons decked to the same height as the liners and sort the CR out in the head. But it's your engine and you need to do what you think is best.
Not strange at all, my engine that done the 12.3 quarter mile was running 8:1.1, did the time at 20psi but ran it at 24psi for the rest of the day.
But, wouldn't that time be factored by many other variables aswell, such as: suspension, wheels, tires, weather, driver.... ?
You could argue that it would/could have run that time with the standard compression.
Either way, I wasn't really commenting on performance... I was more concerned with reliability (HG failure).
Not saying the raised compression was the only reason for my time, just pointing out that its not nessecially a bad thing running slightly higher compression ratio and doesn't always lead to HG failure.
Point taken.
Do you still run that compression ratio now Mark? What made you change in the first place if you don't mind me asking?
No reason why the HG should fail if everything else is in order.
If I was to rebuild another c1j engine again, I'd be going higher c/r for sure.
What reasons would lead you to up'ing the compression ratio Mart?
I've now sold that engine on as i have a Volvo lump in my red 5, but have now got a gt lump in a campus and may raise the compression abit on that next year if it comes apart.Point taken.
Do you still run that compression ratio now Mark? What made you change in the first place if you don't mind me asking?
It was back in 2005 i had it done, can't rerally remember why i had it done
I'd be tempted by an engine conversion, but I'm fond of the little C1J.... to the point I'm keeping the original exhaust manifold to keep that signature GTT sound.I've now sold that engine on as i have a Volvo lump in my red 5, but have now got a gt lump in a campus and may raise the compression abit on that next year if it comes apart.
It was back in 2005 i had it done, can't rerally remember why i had it done
I'll have a good read and talk to a few peeps about this... just need to understand all the implications around do it.
Improved drive-ability, better fuel consumption, torque/hp gain.
I suppose it would help with lag aswell.
Going to look into this.... thanks for the opinions guys.
defo raise the comp, got 3 r5gtts here all on higher comp, 1 c1j running carb, another cj1 runnin efi and my f4r turbo and defo say over the std or low comp its alot better drive
I'd be tempted by an engine conversion, but I'm fond of the little C1J.... to the point I'm keeping the original exhaust manifold to keep that signature GTT sound.
Mostly everyone on here run the oe ex manifold, theres no major gain on any other design over standard
That's good to know GttNutter.
I was going to look into sanding out any roughness in the casting/joins instead of replacing it for a tubular mani - improve the flow while keeping the sound.
Nice... what C.R are they running?defo raise the comp, got 3 r5gtts here all on higher comp, 1 c1j running carb, another cj1 runnin efi and my f4r turbo and defo say over the std or low comp its alot better drive
Woohoo.... my 400th post.
As said compression will give you power/torq and higher comp isnt a problem aslong as its managed correctly. Id build your engine to what you intend to use it for, Id also look in to the piston tapper, yet again depending on your tune...
Would this differ from a normal engine? Honest question.
TBH Rob, I'm fairly confident in putting the engine together and getting it running, but I'm fairly inexperienced when deciding on compression ratios/dished/flat topped/oval pistons/piston tapper etc....Id build your engine to what you intend to use it for, Id also look in to the piston tapper, yet again depending on your tune...
My intention with the engine is for the odd Santa Pod run/track day, but other than that, I want to have a solid, powerful lump under the bonnet.
Depends what you mean by differ?
Raisng the compression is bascily what a turbo is doing, but by shifting the base raito say from 7.1 - 8.1 via pistons/head or what ever, your closer to the det threshold with the same amount of boost pressure, therefore closer for det to occur. If you can control the fueling/ign your fine as said. Also rasing the compression will increase low/mid range torq too so extra torq at given rpm = extra power aswell.
I spend most of my time building drag engines and torq IMO i dont want alot of (of course to a degree or i wouldnt move
But wouldn't raising the boost (for example) a couple of PSI gain any HP/torque advantage that gave back? Plus you'd be less likely to incur det?
PS... It's funny isn't it - a while back a lot of people were going low comp as that was (at least in some eyes) the way to go. Now people are going high comp!
What next alex?But wouldn't raising the boost (for example) a couple of PSI gain any HP/torque advantage that gave back? Plus you'd be less likely to incur det?
PS... It's funny isn't it - a while back a lot of people were going low comp as that was (at least in some eyes) the way to go. Now people are going high comp!
This is pretty much what I mean by differ - by being closer to the det threshold with the same amount of boost etc. It's just certain things that'll have to be taken into account when tuning.
Sorry to be a flid, but what do you mean by a greater tapper? Also, do you think the standard piston to wall clearance would be ok to run 230+ everyday?I spend most of my time building drag engines and torq IMO i dont want alot of (of course to a degree or i wouldnt move
Regarding the heat issues.... I'll be running a bigger rad and a separate oil cooler on a thermostat.... all this being said, the car won't be held wide open for long periods in the higher gears (unless it's doing it's rare Santa Pod run).
Replacing the engine with a good one one, surely!
Replacing the engine with a good one one, surely!
Not sure if that last comment was aimed at me, but I've never been a fan of low(er) c/r & have never advised it on here or to anyone running a c1j.But wouldn't raising the boost (for example) a couple of PSI gain any HP/torque advantage that gave back? Plus you'd be less likely to incur det?
PS... It's funny isn't it - a while back a lot of people were going low comp as that was (at least in some eyes) the way to go. Now people are going high comp!
To a degree o.e c/r is fine, but a higher c/r will always give you improved (off-boost) drive-ability, and naturally more power overall. Of course, that's offset by the fact that, as you rightly say, the detonation threshold point is now lower, but that's nothing that can't be sorted by tweaking the ignition and/or adding a bit more 'on-boost' fuel, running water injection, or even better, running a full efi setup.
For drag applications, where boost is king, it's probably not worth running a high c/r, possibly with the exception of having efi in situ, but for track & everyday road-use, I'd recommend a higher c/r everytime.
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