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Silvertop to ST170?
AntonUK - 20/4/17 at 10:17 PM

Hi All,
I currently have a £50 special 1.8 silvertop zetec in the Ginetta. Running on GSXR ITB's via an ST170 manifold. All pushed through an type 9 box

While looking at options for a little extra power I came across the ST170 engine. After some research it appears it may be a near straight swap with only the alternator/water pump/aux belt modification needed.

I'm making the assumption my raceline sump and water rail will directly swap over, and the Megasquirt can control the VVT.

Am I correct? Is there anything else I need to be aware of?

cliftyhanger - 21/4/17 at 11:33 AM

All correct except:
VVt needs a VVT controller. MS wont do it, will only be on/off which is rubbish. Better off locking the cam if you don't want to properly control the VVT.
The st170 engine is approx 15-20bhp ahead of a blaclktop.

The engine mounts are different too. Sump/water rail etc will swap.

Daf - 21/4/17 at 11:37 AM

I have an ST170 in my car, on GSXR TBs and running an Emerald ECU - I'm switching the VVT on off via the ecu and it made slightly over 170bhp on the Emerald rolling road.

My long term plan is to ditch the VVT as per the post above and fit a pair of verniers - it seems like this is the best way to go from a cost/power point of view.

Essentially it's glorified blacktop zetec so everything you have should be a straight swap

Ugg10 - 21/4/17 at 12:07 PM

quote:
Originally posted by Daf
I have an ST170 in my car, on GSXR TBs and running an Emerald ECU - I'm switching the VVT on off via the ecu and it made slightly over 170bhp on the Emerald rolling road.

My long term plan is to ditch the VVT as per the post above and fit a pair of verniers - it seems like this is the best way to go from a cost/power point of view.

Essentially it's glorified blacktop zetec so everything you have should be a straight swap


I think I read recently the latest k6 emerald ecu will control the vct correctly, if you have a k6 may be worth a call to see if they will update it.

If the vct and cam in the st170 is anything like the puma 1.7 the trick with the on/off vtec type control is to turn it back off at high revs. Jenko on here had a 1.7 puma running omex600. His blog shows graphs opwith and without vct on, basically off gave good low and top end, on gave great mid. Iirc Northampton motorsport tuned his with on at around 2200rpm and back off at 5800rpm and also off at less than 30% load to help economy.

http://paulsj15.blogspot.co.uk/2014/06/more-on-vct-system.html


[img]http://4.bp.blogspot.com/-S95trHvcaZA/U5lksg2rcZI/AAAAAAAAA80/HHjgUQXDrVs/s1600/Vct+comparisson+curves.JPG [/img]

[Edited on 21/4/17 by Ugg10]

Daf - 21/4/17 at 02:19 PM

Some good info there. There is also a company that can supply a controller that just does the VVT (can't remember the name but I did speak to them at Stoneleigh last year).

Personally (and this is only my opinion mind!) I want to get rid of it as I don't think turning it on off really suits a 7 type car, using it properly is a bit of a grey area but by fitting verniers you can open up a bite more potential.

Ugg10 - 21/4/17 at 04:28 PM

https://motorsport-electronics.co.uk/st170-vvt-control-cams-delete-vvt-pro.html

kingster996 - 21/4/17 at 09:59 PM

I nearly went Silvertop (on gsxr itb's) to st170, but due to vvt control ended up going new crate blacktop instead.

Decided the cost of going full vvt or vvt delete was better put towards a zero miles motor instead.

Have to say I'm very happy with the result and a "new" engine is a huge bonus.