Finally got my ef xr8 stroker tuned this week and i cant say im over the moon with it!! It only made 297.2rwhp. I thought it would have made around 330-350hp. It has
347 stroker
AFR 185 heads
Trickflow stage 2 cam, TFS-51402001
Trickflow trackheat manifold
30/lb injectors
Pro-m 75mm MAF
Got it tuned at silverwater automotive and they didnt see a need for fuel pump or reg. They think its making good power but ive seen 347s with more??? I only have a 65mm throttle body, could this be restricting her???
Mate your intake manifold is restricting it for starters.I have been sworn to secrecy but the manifold holds it back.
Absolute rubbish, who ever told you that doesn't know V8 manifolds! Those manifolds can easily handle 500+hp without any restriction at all (flows 250cfm per runner easily), it has been done thousands of times in the US and has always been regarded as one of the better high hp manifolds available.
As for the dyno figures, yeah its a little bit low but depends on the dyno. Was it in shootout mode? If not it may be ok,as most strokers I have seen get around 220-250rwkw but in shootout mode. The 65mm throttle body may hurt it a bit, I would also think your fuel pup is at it's max. I only got 180rwkw with my stock pump, but some have gone further. What was the AF ratio like on the dyno? Also remember that strokers don't need huge kw figures, they rely on massive amounts of torque.
The top of that graph looks a bit flat fro the mods you have done, also doesn't have AF ratio, I assumed they checked that though. I would expect a combo like that to be pulling another 20-30rwkw. What computer mods have you done? You dodn't mention it but I assume you have extractors and a decent exhaust system too. The trottle body, its not the stock one is it, that is only 60mmm.
The top of that graph looks a bit flat fro the mods you have done, also doesn't have AF ratio, I assumed they checked that though. I would expect a combo like that to be pulling another 20-30rwkw. What computer mods have you done? You dodn't mention it but I assume you have extractors and a decent exhaust system too. The trottle body, its not the stock one is it, that is only 60mmm.
Exactly what i was thinking! They said fuel pressure was fine etc, they also installed the 30/lb injectors and MAF and was then tuned with a chiptorque. Good exhaust 1.5/8 pacemakers to twin cats to single stainless 3 inch one muffler. Throttle body measures 65mm inside just before the butterfly.
Throttle body measures 65mm inside just before the butterfly.
TB's are hard to measure and have their narowest point just after the blade from memory, so it could be a stock 60mm one. If that is the case that would be holding you back a fair bit. Probably worth investing in a 70mm BBK/Edelbrock or similar TB and matching EGR spacer.
Sounds like the rest of the package is good, I still have my doubts about the fuel pump, it is really hard to tell if a pump is maxing out just by a FP guage as I am told they often drop pressure and regain so quickly that the guage doesn't pick it up. But seeing they tuned the chiptorque chip (it was a real time tuned chip wasn't it) they would have picked up any leaning out issues so the pump may still be fine.
TB's are hard to measure and have their narowest point just after the blade from memory, so it could be a stock 60mm one. If that is the case that would be holding you back a fair bit. Probably worth investing in a 70mm BBK/Edelbrock or similar TB and matching EGR spacer.
Sounds like the rest of the package is good, I still have my doubts about the fuel pump, it is really hard to tell if a pump is maxing out just by a FP guage as I am told they often drop pressure and regain so quickly that the guage doesn't pick it up. But seeing they tuned the chiptorque chip (it was a real time tuned chip wasn't it) they would have picked up any leaning out issues so the pump may still be fine.
Will it have to be tuned again if i get new throttle body??? The report sheet says
Fuel presure and flow - 2.3lpm @ 42psi - vac hose on @ idle
- 2.2lpm @ 48psi - vac hose off @ idle
I don't know if that means anything to you? I don't really get it.
Will it have to be tuned again if i get new throttle body??? The report sheet says
Fuel presure and flow - 2.3lpm @ 42psi - vac hose on @ idle
- 2.2lpm @ 48psi - vac hose off @ idle
I don't know if that means anything to you? I don't really get it.
Well that is just the FP they set, and IMO that is way too high for 30lb injectors. Usually high FP causes idle problems but if it is running ok, I guess you can leave it there. Normal settings are around 38psi vac on, 42-43psi vac off. I guess you have an adjustable reg if it is running that high. That also doesn't tell if the FP can handle it, AF ratio should though which they should have been testing while tuning on the dyno.
If you get a new TB, you probably don't have to get it tuned again but I would run it on the dyno before giving it full throttle. Reason is that IMO the fuel pump may be at or close to its maximum and if the TB gives you a fair bit more power it may start leaning out your engine. I am sure you wouldn't like a nice new engine to lean out and blow a head gasket (been there, done that).
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