[Mk2] [Turbo] Strangled at high RPM or normal?

[Loser]

I've come from a NASP honda CRX, so maybe it's normal, but i can feel the turbo holding back at high RPM, beyond say 5500. It feels almost like a diesel!

Plugs and air filter have been done, and hopefully by the end of today the lambda will have been done too (failing on emissions ) but none seem to have helped!


But maybe its cause my old car was boring below 5k, and really needed the revs to make it fun? Any help??

[mrfil13]

Might be worth getting a boost gauge on there to see whats going on.

The torque peaks around that point i think, maybe what your feeling, car should still accelerate rapidly though.

Are you using v-power/tesco 99ron fuel? If not it will be retarding ignition timing.

Also maybe worth doing an diagnostic check. Should be a guide on here somewhere, easy as pie to do.

[Goto10]

I've come from a NASP honda CRX, so maybe it's normal, but i can feel the turbo holding back at high RPM, beyond say 5500. It feels almost like a diesel!

Plugs and air filter have been done, and hopefully by the end of today the lambda will have been done too (failing on emissions ) but none seem to have helped!


But maybe its cause my old car was boring below 5k, and really needed the revs to make it fun? Any help??

Knackered cat? Breathing is critical, moreso at higher revs.
Definitely need to see what the boost is doing with a gauge.
Check for any stored error codes too, might be retarded timing or boost.

[Loser]

Well i'm going to fit larry lambda soon (made an adaptor for a universal one at work.. some days (but only some) i love being an engineer )

Also i've reset the ECU (well, the battery's been unplugged for several hours, dont know it's the hazard fuse like a crx), so i've lost any codes and closed loop tuning hopefully so it'll start tuning correctly!



Will have to get a bit inventive.. i've got a vacuum tester, but it does go both ways so it should work. Why is the standard boost gauge so poo?

[mrfil13]

lambda sensor isnt used when on boost, only steady driving. Without a proper gauge you cannot see if you hitting the correct amount of boost, when your hitting it, if its tailing off etc.

[Loser]

Sorry that was about the emissions problem, passed it now! Are emissions tests always so hard?

Boost issue is next, i had used 95 ron, but just diluted it alot with v-power and it still isnt quite right, boost check soon!

[mrfil13]

The 95ron would be causing problems. You want to take it easy until its all gone and replaced with v-power. Then reset the ecu and try again.

95 ron = knock = poor performance + heading towards dead pistons.

[dawolf]

It could well be the fuel but if you have a rev 1/2 the boost level drops off slightly above a certain rpm, should still feel quite fast though.

[Loser]

I think it's a rev 2 (clear fogs, 15's). Its proverbial off a shovel until about 5-5.5k, then dies off, i'm getting used to it now though, coming from a honda where more revs=more go it's a little strange.

Right, now why does my clutch feel weird lol

[daveparf]

i agree with Goto10. knackered cat!

[Loser]

If i de-cat it (its 1993 so i should be ok!) will next year's emissions be impossible?

[gazyang]

if its rev 1/2 boost drops off like a stone! its normal at around 6000revs
the turbo just cant hold boost that high even with a boost controller and decat it don't get much better.
if its a rev 3 then you have a problem they should pull hard and clean all the way to the rev limiter at around 7200revs
ive had 2 rev 1s now and both crap above 6k also 2 friends with the same, we swapped for rev3 ct20 turbo and hey presto pulls like a son of a.....

hope this helps

[gazyang]

also forgot to add yeah the fuel will make big difference, you run it on 95 ron and risk detonation and damage at high revs! the ecu will also retard the ignition also causing power loss up high! also check and replace your dizzy cap if you have'nt already they bu88er up really quike compared to all other cars ive owned! im talking replace every 4000 miles max! thats how crap they are!

1 thing i recomend to all turbo owners is a potent substance called pro boost add this to your petrol when filling and get your ron lvl over 100!
and reset your ecu i can't recomend this stuff enough.
its hard to find but most motor cycle dealers should sell it.

[Loser]

Its started pulling upto about 6 now, i think it might be normal. It has a bleed valve on there (i know i know, i didnt put it there!) so the boost reads off the scale, but should it read that slowly? I'll put my boot down and i'll hear the turbo spool but see nothing on the boost gauge until all of a sudden it jumps up (see video!)

Is this what the ECU is seeing or is this just a crappy boost gauge??

Also note how i gave up on waiting after 6.5k.. I did lift in 3rd (the gear i was in after changing!)

http://www.youtube.com/watch?v=M3L8CmqBI6I




Another really horrible thing is the clutch, any time i exceed 3250 rpm it goes spongey! I can't think of any reason at all for this! Doesn't matter if i'm accelerating hard or not, only if the RPM exceeds 3250. It never fails to disengage though, the bite point will be half way down, but as long as my foots to the floor i've no problems changing or anything, but it's so difficult to be smooth with it changing its bite point every time i change

Another thing i noticed is that the clutch fluid was too high, so i soaked some into a cloth and put the cap back on.. Then a mate and i noticed it smelled like lighter fluid... and it was, the rag burned for 20 mins!!


Is this some bodge i dont know about and have i been diddled? Only had the car a few weeks and im starting to get pi$$ed off with it.

[gazyang]

glad to hear its started to pull better now but if you can try and get hold of a ct20 turbo from a rev3 they are so much better and bolt straight on too.

sounds like the clutch needs bleeding, and yeah clutch fluid is flamable same as brake fluid.

if your gonna bleed the clutch the car has to be raised at the rear to help any air in that direction to the bleed nipple, check for fluid leek at the clutch cylinder in the front and at the piston on the gear box, mine had a leak there.

also my boost guage does the same thing and also have cheap boost controller on the car. remove the granger valve and join the pipe back together and see if its better.

granger valve are only a cheap option and i found they can cause turbo lag some times depending on what gear your in and the revs your at.

try this for a test, drive the car in second gear and hold it at about 2500revs then floor it and see how it responds then, then try it again at 3000revs. you should notice when holding the revs like that it wont suffer the lag and the gauge should fly straight up

if you really want to get it shifting when moving and know your not in the power try clutching it but beware do this to often and you will eat your clutch, but its great for racing and annoying people who try and over take you in there hot hatches lol

[Loser]

Just think it's so strange that i only get clutch problems after 3250 RPM, but i will bleed it soon, also never knew brake fluid was flammable??? Think i'll have some DOT 5.1 knocking around somewhere, the clutch system wont care if i've got old DOT in there will it, with the water and such. Like you should always use fresh fluid for brakes?

Had some of the IC pipes off and there was a little oil in there, nothing major though, but maybe enough of an excuse to upgrade the turbo later.


Dont have much of a problem with lag, to be honest, but coming from a naturally asperiated honda (permanent turbo lag:P) so i'm kinda used to it!

With the boost gauge i'm hoping that's not what the ECU is seeing (although i guess it maps RPM vs. MAF so i dont suppose the 'seen' boost pressure will be too much of an issue!)

[Steve-O 2007]

Did you say you still had a cat fitted? If so Get that off asap.. You dont need a Cat for MOT

Also do you have the stock exhaust fitted? If so get an aftermarket one fired on

[Loser]

It's stock yeah, but my CRX was incredably noisy, and it pi$$ed me off to be honest! Is the standard system so restrictive??

[Drifter]

get rid of the cat, get a nice flowing exhaust system, uprate ya turbo, ST205 CC and your sorted o and a boost controller

[Lou-Lou]

I always ran my Mk2 Turbo on 95... never did it any harm!