Evo 8 Dyno Results *Air flow issue*
The wga was readjusted shut tight, and same problem. We did a boost leak test also and nothing.
Acually on the way home i did get a egr CEL P0401, the little hose in the back poped off. but i thought that code doesnt effect the performance of the car?
Acually on the way home i did get a egr CEL P0401, the little hose in the back poped off. but i thought that code doesnt effect the performance of the car?
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Evolving Member
Joined: Nov 2008
Posts: 424
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From: Russia, Moscow
I had two cars with the same problem, but didnt have a chance to sort out that problem..
Both cars had engines in good condition - compression 170psi and leak test less then ~5%.
First car had a built engine, new ATP turbo GTX3071(and later 3076 that behaved the same way), Cosworth M2 cams, 3" exhaust, 3" IC and piping... Full boost 25 psi @ 4700, Max power 355whp at 6000rpm on mustang dyno.
Second car had stock engine, new Tomei ARMS that spooled almost like GTX3076 full boost 26psi at 4600rpm, Kelford 272 cams, 3" exhaust, 3" IC and piping etc etc... It made some kind of power, but spooled way too slow and the owner didnt want to sort that out and swapped to a good GTX3071 turbokit (t3 or t4) with external WG dump. Full boost 26psi at 4500rpm in 4th gear, VD showed max power of 370whp dynojet.
Both cars are on ron98 (92oct), run 11.5-11.2 AFR, reasonable ignition timing but a bit on a lower side, and run lower load than other cars. Seems like airflow problems...
Both cars had engines in good condition - compression 170psi and leak test less then ~5%.
First car had a built engine, new ATP turbo GTX3071(and later 3076 that behaved the same way), Cosworth M2 cams, 3" exhaust, 3" IC and piping... Full boost 25 psi @ 4700, Max power 355whp at 6000rpm on mustang dyno.
Second car had stock engine, new Tomei ARMS that spooled almost like GTX3076 full boost 26psi at 4600rpm, Kelford 272 cams, 3" exhaust, 3" IC and piping etc etc... It made some kind of power, but spooled way too slow and the owner didnt want to sort that out and swapped to a good GTX3071 turbokit (t3 or t4) with external WG dump. Full boost 26psi at 4500rpm in 4th gear, VD showed max power of 370whp dynojet.
Both cars are on ron98 (92oct), run 11.5-11.2 AFR, reasonable ignition timing but a bit on a lower side, and run lower load than other cars. Seems like airflow problems...
I had two cars with the same problem, but didnt have a chance to sort out that problem..
Both cars had engines in good condition - compression 170psi and leak test less then ~5%.
First car had a built engine, new ATP turbo GTX3071(and later 3076 that behaved the same way), Cosworth M2 cams, 3" exhaust, 3" IC and piping... Full boost 25 psi @ 4700, Max power 355whp at 6000rpm on mustang dyno.
Second car had stock engine, new Tomei ARMS that spooled almost like GTX3076 full boost 26psi at 4600rpm, Kelford 272 cams, 3" exhaust, 3" IC and piping etc etc... It made some kind of power, but spooled way too slow and the owner didnt want to sort that out and swapped to a good GTX3071 turbokit (t3 or t4) with external WG dump. Full boost 26psi at 4500rpm in 4th gear, VD showed max power of 370whp dynojet.
Both cars are on ron98 (92oct), run 11.5-11.2 AFR, reasonable ignition timing but a bit on a lower side, and run lower load than other cars. Seems like airflow problems...
Both cars had engines in good condition - compression 170psi and leak test less then ~5%.
First car had a built engine, new ATP turbo GTX3071(and later 3076 that behaved the same way), Cosworth M2 cams, 3" exhaust, 3" IC and piping... Full boost 25 psi @ 4700, Max power 355whp at 6000rpm on mustang dyno.
Second car had stock engine, new Tomei ARMS that spooled almost like GTX3076 full boost 26psi at 4600rpm, Kelford 272 cams, 3" exhaust, 3" IC and piping etc etc... It made some kind of power, but spooled way too slow and the owner didnt want to sort that out and swapped to a good GTX3071 turbokit (t3 or t4) with external WG dump. Full boost 26psi at 4500rpm in 4th gear, VD showed max power of 370whp dynojet.
Both cars are on ron98 (92oct), run 11.5-11.2 AFR, reasonable ignition timing but a bit on a lower side, and run lower load than other cars. Seems like airflow problems...
165psi is very healthy for our cars. Especially with cams. don't let anyone else tell you otherwise.
All Journal bearing turbos have some up and down shaft play. Its normal. In and out is what you don't want.
You could try dropping the downpipe to see if the spool increases drastically to see if there is some kind of restriction in the exhaust system causing severe backpressure.
Usually things that cause your graph are:
1. severe boost leak somewhere
2. compromised/restricted/clogged exhaust system
3. internal wastegate failure / issue (could be the actuator itself, or the flapper not seating properly)
Heres my recommendation to you to bypass everything and start from a baseline:
Drop the downpipe
Route the vacuum line from the wastegate directly to the intake manifold or compressor pipe coming off the turbo elbow. (This will run wastegate pressure only)
Do a pull. If its still lazy then its not the exhaust system. It could still be the flapper not seating properly though and causing it to not hold boost releasing exhaust gases causing a very lazy spool.
Wouldn't hurt to check the timing to make sure nothing moved also mechanically.
All Journal bearing turbos have some up and down shaft play. Its normal. In and out is what you don't want.
You could try dropping the downpipe to see if the spool increases drastically to see if there is some kind of restriction in the exhaust system causing severe backpressure.
Usually things that cause your graph are:
1. severe boost leak somewhere
2. compromised/restricted/clogged exhaust system
3. internal wastegate failure / issue (could be the actuator itself, or the flapper not seating properly)
Heres my recommendation to you to bypass everything and start from a baseline:
Drop the downpipe
Route the vacuum line from the wastegate directly to the intake manifold or compressor pipe coming off the turbo elbow. (This will run wastegate pressure only)
Do a pull. If its still lazy then its not the exhaust system. It could still be the flapper not seating properly though and causing it to not hold boost releasing exhaust gases causing a very lazy spool.
Wouldn't hurt to check the timing to make sure nothing moved also mechanically.
165psi is very healthy for our cars. Especially with cams. don't let anyone else tell you otherwise.
All Journal bearing turbos have some up and down shaft play. Its normal. In and out is what you don't want.
You could try dropping the downpipe to see if the spool increases drastically to see if there is some kind of restriction in the exhaust system causing severe backpressure.
Usually things that cause your graph are:
1. severe boost leak somewhere
2. compromised/restricted/clogged exhaust system
3. internal wastegate failure / issue (could be the actuator itself, or the flapper not seating properly)
Heres my recommendation to you to bypass everything and start from a baseline:
Drop the downpipe
Route the vacuum line from the wastegate directly to the intake manifold or compressor pipe coming off the turbo elbow. (This will run wastegate pressure only)
Do a pull. If its still lazy then its not the exhaust system. It could still be the flapper not seating properly though and causing it to not hold boost releasing exhaust gases causing a very lazy spool.
Wouldn't hurt to check the timing to make sure nothing moved also mechanically.
All Journal bearing turbos have some up and down shaft play. Its normal. In and out is what you don't want.
You could try dropping the downpipe to see if the spool increases drastically to see if there is some kind of restriction in the exhaust system causing severe backpressure.
Usually things that cause your graph are:
1. severe boost leak somewhere
2. compromised/restricted/clogged exhaust system
3. internal wastegate failure / issue (could be the actuator itself, or the flapper not seating properly)
Heres my recommendation to you to bypass everything and start from a baseline:
Drop the downpipe
Route the vacuum line from the wastegate directly to the intake manifold or compressor pipe coming off the turbo elbow. (This will run wastegate pressure only)
Do a pull. If its still lazy then its not the exhaust system. It could still be the flapper not seating properly though and causing it to not hold boost releasing exhaust gases causing a very lazy spool.
Wouldn't hurt to check the timing to make sure nothing moved also mechanically.
My exhaust system is a straight pipe and is only 1k miles on it.
Could it be my intercooler?? Its the new ams cast iron one, i doubt its clogged.
Maybe it is the wastegate. Could a bad turbo cause this? It has no in and out and there is no oil on the hot side when i took it out.
Definitely need to check cam timing. just disconnect the gate and do a quick pull(be ready to lift as it comes into boost, as there will be no control) to see if it spools up ok. Just remember, be ready to lift, as with the wastegate disconnected it will not open till wayyy too late. Only do that though after checking your cam timing. Hey, btw, while you're at it, check the cam timing.
Definitely need to check cam timing. just disconnect the gate and do a quick pull(be ready to lift as it comes into boost, as there will be no control) to see if it spools up ok. Just remember, be ready to lift, as with the wastegate disconnected it will not open till wayyy too late. Only do that though after checking your cam timing. Hey, btw, while you're at it, check the cam timing.
What power goals are you expecting? How are your spark plugs? Any engine knock? I know you checked for boost leaks but did you check for exhaust leaks? What size intercooler are you using and piping?