phew what a week of projects.

[paulob1]

ah okay very useful...

 

[PumaNoob]

the diff wont put any extra force on 5th gear really

An LSD will put extra load on all the drive train components. With an open diff, once a certain pressure threshold is reached (the traction of 1 tyre), the tyre gives way and spins. An LSD will put nearly twice the torque stress through the drivetrain when pushed hard as it will take nearly twice the torque before the wheels spin.

5th gear takes the most load in the box out of all the gears, the engine will produce the same power at the same rpm, so if you have 200bhp in 1st, its easy for the engine to turn the wheels, but in 5th, you are putting 200bhp through the engine, but the gearbox is struggling to turn the wheels so easily because there is a lot more load on that gear. Its like gears on a pushbike, the lower gears are easier to pedal (less load on your legs), but if you put it into a high gear your legs have to work harder to turn the wheels (more load on your legs). Your legs are still as powerful as they were before, but the chain has to take more load from them to turn the wheels. Its the same principal with a car.

 

[ScubaSteve]

yeah but you wont be spinning the wheels in 5th though, even with 200bhp or whatever, so the diff isnt really putting any extra load on fifth explicitly.

it could simply be too much power for the box, as you say 5th does indeed take the most force from the engine

 

[PumaNoob]

Yeah fair point, I suppose its only adding load when traction breaks away, but when your cornering your not likely to be in 5th, and most won't spin in 5th anyway.

 

[ScubaSteve]

ur my m8

 

[paulob1]

its only a nitrous engined car, 25 bhp jets say maximum 180 bhp, maybe a tad more as it is quicker than turbo puma which has 180 bhp....

so power cannot be the issue...and turbo puma never seen anything other than a std 1.7 gearbox...

 

[PumaNoob]

Bhp don't really mean so much with gearboxes, you might not have much bhp but a truck load of torque. Torque is what kills boxes. Maybe you just need a complete box rebuild and a lighter right foot :lol: I'd try the internals from a focus 1.4, or a fiesta st150, they are supposed to be stronger then the puma internals. If the cars not for cruising, but more for acceleration, get the smallest wheels possible and the shortest gearing, that's the least stress on drivetrain. I changed my 17"s on my green puma for 16's for that reason. There are quite a few people running decent torque through IB5 boxes now, so might just be a dodgy box, all it takes is a slight warp in the main or lay shaft, & the stresses are dramatically increased.

 

[paulob1]

I have destroyed 3 boxes now..

turbo puma sprung another oil leak. its being sorted again...but running real sweet and with the coilocvers it handles nearly as well as the frp...

I am fitting megasquirt to it next week, with a few additional sensors so i can get a feel for what is going on inside the engine...

The plan then being I will then build the steel engine with a view to making around 300 bhp using the gt28 turbo and a slightly modified head...going to keep the VVT i think but will see..I would like to bang this baby up to 9000 rpm but not sure if that is worth the reliability issues...

the f3 engine will be here late this week and i start work on that, still got to get the car to put it in and am going to fit an mtx 75 box to start with then if that doesnt work have a quaife set of internals built...going to be an expensive car this...

just bought myself a couple of subaru twin turbo cars to remove the engines and fit to two new buggys...300 bhp in one of those will be totally mad...also looking for a good wrx to play with and have as a daily driver over winter...

also got a 175bhp engine which will go into the other chassis...will then have a 150 bhp, a 175bhp and two 300 bhp buggies to go playing with...crazy me thinks...

 

[RyanG]

Vvt with the gt28 sounds good will megasquirt ecu run that ?

That engine will surely need the mtx box more than the f3 engine I'd imagine it would make nearly half the tourque of the turbo engine.

Also will it not be over geared with the mtx box I think you said it will rev to near 9k ?

 

[PumaNoob]

For the VVT you'd have to run the MS alongside the standard ECU to get the VVT working correctly, like I did with my green puma turbo. The good thing with the puma ecu is it will still run even if its not controlling the spark or fuel!

 

[RyanG]

For the VVT you'd have to run the MS alongside the standard ECU to get the VVT working correctly, like I did with my green puma turbo. The good thing with the puma ecu is it will still run even if its not controlling the spark or fuel!

I see but you couldn't adjust the vvt with the megasquirt to help it come on boost better then peak higher aswell it would be set to standard puma vvt settings ?

 

[paulob1]

Megasquirt piggy back on turbo 1.

megasquirt on F3 engine and not totally sure about the heavy duty steel engine yet...want to keep the vvt even though many have said remove it. Will see how easy it is to remove it then have a play...perhaps build it with and without. and see what I get in driveability, my thoughts are that with the turbo i can adjust most things to make it driveable, and the vvt will only make the car more useable at low revs so it may as well stay...

 

[PumaNoob]

For the VVT you'd have to run the MS alongside the standard ECU to get the VVT working correctly, like I did with my green puma turbo. The good thing with the puma ecu is it will still run even if its not controlling the spark or fuel!

I see but you couldn't adjust the vvt with the megasquirt to help it come on boost better then peak higher aswell it would be set to standard puma vvt settings ?

Nah, megasquirt is a very good bit of kit, but its also very basic so it wont run the puma VCT. It would run it like a V-Tec, either fully on or fully off. The only way you could adjust it slightly would be with cam timing, and then your still limited to a specific band, youd move it up the rev range or down. There may be a way around it, but not that i know of.

you'll have to look into cam selection, lift and duration for the 9k rpm engine, makesure you have the clearence. Id also check that the VCT can sustain the pressure of those revs, its only held advanced by oil pressure, and not designed to work higher then 7200rpm. It may be ok but its worth a check. It would be good to put the VCT more gradual on that engine, then you could get a more specific cam, at standard settings, your going to get no advance between about 3500rpm and 9000 rpm, so its sort of pointless having vct as youll spend most your time on a track in that rev range.

 

[RyanG]

For the VVT you'd have to run the MS alongside the standard ECU to get the VVT working correctly, like I did with my green puma turbo. The good thing with the puma ecu is it will still run even if its not controlling the spark or fuel!

I see but you couldn't adjust the vvt with the megasquirt to help it come on boost better then peak higher aswell it would be set to standard puma vvt settings ?

Nah, megasquirt is a very good bit of kit, but its also very basic so it wont run the puma VCT. It would run it like a V-Tec, either fully on or fully off. The only way you could adjust it slightly would be with cam timing, and then your still limited to a specific band, youd move it up the rev range or down. There may be a way around it, but not that i know of.

you'll have to look into cam selection, lift and duration for the 9k rpm engine, makesure you have the clearence. Id also check that the VCT can sustain the pressure of those revs, its only held advanced by oil pressure, and not designed to work higher then 7200rpm. It may be ok but its worth a check. It would be good to put the VCT more gradual on that engine, then you could get a more specific cam, at standard settings, your going to get no advance between about 3500rpm and 9000 rpm, so its sort of pointless having vct as youll spend most your time on a track in that rev range.

Ok, I think its pointless having the vct if you can't adjust it that's the point of keeping it. With the size of cam you will need to keep power at 9k rpm it won't be as drivable down the bottom or tick over very well so the vct will definately be needed in my opinion.

The vct was fine at 10500rpm that's as far as they wanted to test it.
The ecu I run and having the engine on the Dyno, you can sit the engine at 9000rpm then advance and retard the inlet cam and hear, watch make more or less power

 

[Ginger Tom]

When I get the xr2 done I might get you and your dad to set it up for me k:

 

[paulob1]

its ryan that has committed me keeping it active and I agree with him, with the vvt/ vct it will be more driveable at low rpm...he is using the pectel ecu I think arent you ryan, you said that could do the vvt too...it may be worth a look but am happy for now with the megasquirt...with all my projects i am short handed and I am buying myself four Subarus, turbo leagacy 180 bhp, two twin turbo 300 bhp cars and one wrx with 280 bhp...the 280 car is going to be my winter hack as i wont have my pumas ready this winter...other than turbo nitrous and pumaspeed...419 is getting welded this month and will be back on the road in std format as her engine is so sweet....088 is getting the f3 engine, and that work will start next week once i have collected the engine...bad news is customer work is on the up again and we are busy again so time will be short.

AM going to stick a turbo on nitrous too aiming for just 200 bhp without nitrous and a further 25-30 bhp with, thats enough for that car...

son getting involved with the subaru buggy upgrades so that should help a lot...buggy plan though includes using the std 5 speed subaru box and two wheel drive...should work really well and i dont have to spend a fortune upgrading the four speed bettle box which is a real yawn box...mind you makes the car safer as it will not allow the car to go much above 100 mph and buggys should not be going much faster than that...

 

[PumaNoob]

But that's the point, to utilise the VCT properly with the high rpm's, you really need to have full control over it, but the MS doesn't have the capability to do that. It will be fine on the turbo puma as you won't be revving it past normal rpm limit.

The only way to do it with the ms as a piggyback is to reprogramme the standard ECU too. If your going to go through that you might as well just go for the pectel ECU from the start.

 

[RyanG]

When I get the xr2 done I might get you and your dad to set it up for me k:

Happily mate only issue is the engine has to be on pectel and out the car for the Dyno, an issue for some people but I love it not having to run in the engine for 100's of miles in the car lol.

 

[RyanG]

its ryan that has committed me keeping it active and I agree with him, with the vvt/ vct it will be more driveable at low rpm...he is using the pectel ecu I think arent you ryan, you said that could do the vvt too...it may be worth a look but am happy for now with the megasquirt...with all my projects i am short handed and I am buying myself four Subarus, turbo leagacy 180 bhp, two twin turbo 300 bhp cars and one wrx with 280 bhp...the 280 car is going to be my winter hack as i wont have my pumas ready this winter...other than turbo nitrous and pumaspeed...419 is getting welded this month and will be back on the road in std format as her engine is so sweet....088 is getting the f3 engine, and that work will start next week once i have collected the engine...bad news is customer work is on the up again and we are busy again so time will be short.

AM going to stick a turbo on nitrous too aiming for just 200 bhp without nitrous and a further 25-30 bhp with, thats enough for that car...

son getting involved with the subaru buggy upgrades so that should help a lot...buggy plan though includes using the std 5 speed subaru box and two wheel drive...should work really well and i dont have to spend a fortune upgrading the four speed bettle box which is a real yawn box...mind you makes the car safer as it will not allow the car to go much above 100 mph and buggys should not be going much faster than that...

Yes pectel I'm using I would like to build a turbo engine and have the vct working properly but at my age two big engines is a bit too expensive even with the help I get

The Subaru buggies sound amazing fun

 

[RyanG]

But that's the point, to utilise the VCT properly with the high rpm's, you really need to have full control over it, but the MS doesn't have the capability to do that. It will be fine on the turbo puma as you won't be revving it past normal rpm limit.

The only way to do it with the ms as a piggyback is to reprogramme the standard ECU too. If your going to go through that you might as well just go for the pectel ECU from the start.

Your right with a normal turbo engine but Paul wants to rev his New one.

Sounds complicated with both ecu's I suppose with pectel I've got it easy