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Recently purchased a 1968 Volvo Amazon with a gen 1 4G63. The car is a hoot and fairly well sorted for track use. However, boost comes on late and hard! This isn’t the best for road racing. From what I can tell it was built in 2016 with the finest of late 90’s tech. Build specs are below. What changes can I make to widen the power band? I’d like it to scroll more quickly and rev to 8k. I don’t mind changing cams, turbo, fuel, haltech and tuning. I don’t really want to do anything to the bottom end.
So I think its probably broken and you should give me a good deal on it lol.
But to actually answer the question, you'll likely need to switch turbos or hotside? I mean that's not a very big turbo so its a bit strange that it comes on so late.
What fuel are you running? There might be some gains to be had there.
That turbo should be capable of another 200HP. Switch to E85, retune and see if you like it from there. I assume the current tune is not very aggressive, I'd tell you go smaller on the turbo but that's not in my vocabulary.
A "400-500hp" turbo should be making 300ft-lbs at or under 3500 rpms so making that laggy of 350hp says something is definitely wrong.
A quick google of that turbo, it looks like its a cheap mid 5xx unit though no clue if its turbine is sized appropriate for a 4cyl. Id guess one of a few issues,
Just plain ol wrong turbo for the application
WG isnt holding closed.
CAM timing is off, though not sure it can be enough to make it this bad.
A "400-500hp" turbo should be making 300ft-lbs at or under 3500 rpms so making that laggy of 350hp says something is definitely wrong.
A quick google of that turbo, it looks like its a cheap mid 5xx unit though no clue if its turbine is sized appropriate for a 4cyl. Id guess one of a few issues,
Just plain ol wrong turbo for the application
WG isnt holding closed.
CAM timing is off, though not sure it can be enough to make it this bad.
thank you for the reply. Those are some good variables to look into. Would it be a good idea to start with a haltech, retune from a competent shop, and go from there?
91 pump gas. Could do e85, but not actually wanting more power, just need more response. The T5 can only handle 300 torque.
Originally Posted by DW Dave
thank you for the reply. Those are some good variables to look into. Would it be a good idea to start with a haltech, retune from a competent shop, and go from there?
E85 could help wake it up earlier in the RPMs as well with the added timing.
I would generally agree with Dallas J. I would check the WG but to me, this reads like the wrong size turbo for the goals. I would do some research about what hotside you have to start and other turbo options that are a hair smaller. Try and find something closer in size to a factory turbo or like a 16G but new tech.
As for the haltech, sure they are nice but honestly, the factory ECU probably isn't your limiting factor. If you want to move to an aftermarket ECU for added sensors and safety for tracking the car, I think thats a decent idea but it isn't going to be the thing that fixes the spool.
That turbo is old, it shouldnt spool that bad, but it def wouldnt be "great". That manifold may mot be helping either. A g25-660 would probably help a lot.
Beautiful car dude!
