Power drop off.

Post 585026 by stribo on 2013-03-16 20:45:12

Having had my car on the rollers twice in a couple of months, I've noticed that although I'm getting good torque, it's dropping off early in the rev range (between 4K and 4.5K), and this is affecting the bhp. I've fitted a bleed valve before the TCV (which is still connected) and it's holding about 0.9 bar all the way up to the red line. The RR operator today was surprised at the graphs, as he said it felt strong all the way up the rev range, but thought it might be something to do with the ECU, so would a remap sort this? My power graphs: 1st at Power Engineering: and todays at Southways:

Post 585028 by M-R-P on 2013-03-16 20:46:52

Naaah, it's 'cos your car's gay... and gold... and gay-gold ;) Buy another P2 and be happy ;)

Post 585030 by LiamT4 on 2013-03-16 20:47:56

Do bleed valves bring the power in early like mbc's do? Is your car an me7?

Post 585031 by stribo on 2013-03-16 20:49:16

[QUOTE=LiamT4;585030]Do bleed valves bring the power in early like mbc's do? Is your car an me7?[/QUOTE] Power does seem to come in earlier, but unlike without it, it holds the boost without much drop off, and luckily it's pre ME7 :D

Post 585032 by merc85 on 2013-03-16 20:49:40

sounds like the Turbo actuator could be going weak, also a walbro pump will help the power up top no end.

Post 585034 by Jamest5r on 2013-03-16 20:50:54

That's just simply the actuator bleeding your boost off, it might be the way a standard map does it i dont know, why havent you got a map anyway lol

Post 585036 by stribo on 2013-03-16 20:52:32

[QUOTE=M-R-P;585028]Naaah, it's 'cos your car's gay... and gold... and gay-gold ;) Buy another P2 and be happy ;)[/QUOTE] It's got a lot more torque than your tank, and only 6 BHP less. :P Fancy working out the power to weight ratios? because I win. :hilarious

Post 585037 by LiamT4 on 2013-03-16 20:53:30

I'd say maybe a weak actuator, but you can feel that and usually it won't hold the boost either.

Post 585038 by stribo on 2013-03-16 20:54:36

[QUOTE=merc85;585032]sounds like the Turbo actuator could be going weak, also a walbro pump will help the power up top no end.[/QUOTE] [QUOTE=Jamest5r;585034]That's just simply the actuator bleeding your boost off, it might be the way a standard map does it i dont know, why havent you got a map anyway lol[/QUOTE] Surely if it was the actuator it wouldn't hold boost. I'll be getting it remapped soon James, after all, running a 1/4 mile with an unmapped car is a no no. ;)

Post 585039 by smithy on 2013-03-16 20:55:34

Is your car me7 or not , if not connect then bleed valve or better get a mbc and connect it direct not including the bcs.also the power is about right for a unmapped c70 mate.try tightening the actuator abit too.

Post 585040 by merc85 on 2013-03-16 20:56:54

actuators dont just fail, they get worse over time, disconnet the vac line to the actuator see how it holds boost then. Word of warning tho, she could over boost if you dont watch the gauge.

Post 585042 by stribo on 2013-03-16 20:59:16

I have a boost guage, and it holds 0.9 bar (about 14 psi) all the way to the redline.

Post 585045 by LiamT4 on 2013-03-16 20:59:42

When my actuator was on its way out, it would hit about 14psi@3000rpm, then once past 4k it would drop untill it was only about 6-7psi at 6k.

Post 585047 by V70 Graham on 2013-03-16 21:00:43

Today's graph is better than last times though, doesn't tail off as quickly.

Post 585049 by stribo on 2013-03-16 21:01:23

boost isn't dropping though.

Post 585051 by smithy on 2013-03-16 21:04:24

Remap it mate 150 pounds is a good deal and if you go to hlm then they can tweak the car to make sure it powers right on the rollers too.

Post 585052 by oblark on 2013-03-16 21:05:11

At least you got to 5k :P

Post 585061 by stribo on 2013-03-16 21:20:05

[QUOTE=smithy;585051]Remap it mate 150 pounds is a good deal and if you go to hlm then they can tweak the car to make sure it powers right on the rollers too.[/QUOTE] Do they do live remapping, as I'd rather that than just a generic 304/310 map? [QUOTE=oblark;585052]At least you got to 5k :P[/QUOTE] Yeah, but your's made the best pops and bangs. ;)

Post 585064 by oblark on 2013-03-16 21:22:53

It pulled like a trooper in 4th up to 5k rpm coming out of pompey on the way home, so not sure what the problem is.

Post 585069 by T5frankie on 2013-03-16 21:27:34

the thing with bleed valves and mbc's you get a large lump of torque early for the sake of losing it higher up the rev range

Post 585070 by T5frankie on 2013-03-16 21:28:17

[QUOTE=stribo;585061]Do they do live remapping, as I'd rather that than just a generic 304/310 map? Yeah, but your's made the best pops and bangs. ;)[/QUOTE] not for 150 quid they don't

Post 585074 by stribo on 2013-03-16 21:32:29

No, I assumed it would cost more, just wondering if they did it. I'm guessing the generic remap is an exchange ECU.

Post 585076 by LiamT4 on 2013-03-16 21:33:16

[QUOTE=stribo;585061]Do they do live remapping, as I'd rather that than just a generic 304/310 map?[/QUOTE] Not many places can do custom maps for the old motronic ecu's.

Post 585078 by stribo on 2013-03-16 21:33:56

[QUOTE=T5frankie;585069]the thing with bleed valves and mbc's you get a large lump of torque early for the sake of losing it higher up the rev range[/QUOTE] It's just strange (to me) how it's holding boost but losing power (torque). Just to throw it out there, a dodgy wheel bearing wouldn't make any difference would it?

Post 585079 by T5frankie on 2013-03-16 21:34:13

[QUOTE=stribo;585074]No, I assumed it would cost more, just wondering if they did it. I'm guessing the generic remap is an exchange ECU.[/QUOTE] yes mate, custom maps are only needed for extreme changes in pipework, fueling, exhausts turbos etc

Post 585085 by stribo on 2013-03-16 21:36:49

Well, for £150 I guess it's worth a punt, so do I want the 310? I've got white's and 16t.

Post 585087 by T5frankie on 2013-03-16 21:38:45

[QUOTE=stribo;585085]Well, for £150 I guess it's worth a punt, so do I want the 310? I've got white's and 16t.[/QUOTE] no mate 304 for you the 310 is for 18t, take the bleed valve off mate

Post 585088 by LiamT4 on 2013-03-16 21:38:59

Think its a 310 for the 18t and 304 for the 16t.

Post 585090 by stribo on 2013-03-16 21:40:41

[QUOTE=T5frankie;585087]no mate 304 for you the 310 is for 18t, take the bleed valve off mate[/QUOTE] Oh yeah, I only fitted that as a temporary (cheap) measure.;)

Post 585091 by T5frankie on 2013-03-16 21:40:54

[QUOTE=stribo;585078]It's just strange (to me) how it's holding boost but losing power (torque). Just to throw it out there, a dodgy wheel bearing wouldn't make any difference would it?[/QUOTE] i have used an mbc for a couple of years for racing and while they are good for early-mid range you will lose power at the top end, thats why i never got any high terminals on the 1/4 mile

Post 585092 by V70 Graham on 2013-03-16 21:42:05

RIP kit would be a good idea too mate, get the turbo spooling quicker.

Post 585093 by stribo on 2013-03-16 21:43:35

[QUOTE=T5frankie;585091]i have used an mbc for a couple of years for racing and while they are good for early-mid range you will lose power at the top end, thats why i never got any high terminals on the 1/4 mile[/QUOTE] Yeah, I suppose they're never going to be as good as a remap, otherwise everyone would just fit one, and forget about remapping.

Post 585096 by stribo on 2013-03-16 21:44:24

[QUOTE=V70 Graham;585092]RIP kit would be a good idea too mate, get the turbo spooling quicker.[/QUOTE] I'm waiting for you to say you don't like your's, then I'll get it cheap. ;) :P

Post 585097 by V70 Graham on 2013-03-16 21:46:00

[QUOTE=stribo;585096]I'm waiting for you to say you don't like your's, then I'll get it cheap. ;) :P[/QUOTE] Hahahaha nice try, it's staying lol, ME7 too so there !

Post 585100 by stribo on 2013-03-16 21:49:49

[QUOTE=V70 Graham;585097]Hahahaha nice try, it's staying lol, ME7 too so there ![/QUOTE] I'll just have the top pipe then :P

Post 585169 by smithy on 2013-03-16 22:28:54

I don't have a problem using an mbc as long as you have a good actuator like I have .but on your car I would go with a remap as see what you think from there.and I would go and get the car setup properly too to get the most benefit from it too.

Post 585186 by stribo on 2013-03-16 22:49:20

[QUOTE=smithy;585169]I don't have a problem using an mbc as long as you have a good actuator like I have .but on your car I would go with a remap as see what you think from there.and I would go and get the car setup properly too to get the most benefit from it too.[/QUOTE] Looks like a trip to Bromsgrove then ;) I'll have to finish my stage 0 first.