S2 -> 3.0L turbo. How much?
04-13-2010, 10:50 AM
#1
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S2 -> 3.0L turbo. How much?
OK, just for fun, let's suppose I'm going to turbo my (S2) NA.
Main parts:
1989 2.7L head, w/ 951 exhaust valves
951 airbox, AFM, intake manifold
951 exhaust headers and crossover plumbing etc.
951 injectors and DME (or standalone if that makes more sense).
951 IC, hard pipes
951 turbo head, wastegate etc.
Apart from from engine internals to lower CR, anything important I've missed?
For lowering the CR to (say) 8.5:1, what are the options? What would simply using a 951 crank achieve (would this work with S2 pistons)? Do you actually _need_ custom pistons?
And how much am I up to ($$$) so far?
This is all crazy talk, of course. Not _really_ going to do this. No sirreee...
Main parts:
1989 2.7L head, w/ 951 exhaust valves
951 airbox, AFM, intake manifold
951 exhaust headers and crossover plumbing etc.
951 injectors and DME (or standalone if that makes more sense).
951 IC, hard pipes
951 turbo head, wastegate etc.
Apart from from engine internals to lower CR, anything important I've missed?
For lowering the CR to (say) 8.5:1, what are the options? What would simply using a 951 crank achieve (would this work with S2 pistons)? Do you actually _need_ custom pistons?
And how much am I up to ($$$) so far?
This is all crazy talk, of course. Not _really_ going to do this. No sirreee...
04-13-2010, 11:15 AM
#2
Three Wheelin'
Well to start youd need custom pistons or a very thick cometic headgasket. The 951crank has a different stroke, so youd use your S2 crank.
Are you doing the labor yourself or taking it to a shop?
Are you doing the labor yourself or taking it to a shop?
04-13-2010, 11:50 AM
#3
Drifting
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If your carful you could do it for 5k
you can turbo the S2 engine as is run 98 fuel and 10 or 12 psi and make 400hp..
of if you want to go single came i can sell you a good pile of stuff to get started ..for 2 or 3 k
ported reco head intercooler extrude honned inlet programmable Ecu cross over and 3" exhuast ..
you can use the pistons you have you just have to be carful ...
you can turbo the S2 engine as is run 98 fuel and 10 or 12 psi and make 400hp..
of if you want to go single came i can sell you a good pile of stuff to get started ..for 2 or 3 k
ported reco head intercooler extrude honned inlet programmable Ecu cross over and 3" exhuast ..
you can use the pistons you have you just have to be carful ...
04-13-2010, 02:57 PM
#6
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5K - 7K is not out of the question in my opinion and that would be a fairly cheap build up- if you can call it that. You need a turbo and all of its associated parts like WG, exhaust, injectors, proper tuning etc...these are easily several Ks right there. Then you've got to make sure your suspension/brakes are up to task = more $$$. Labor is costly as well so factor that in...
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04-13-2010, 03:25 PM
#8
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ehall - I agree. I mean, if you are going a complete built up, do it once and do it right - sad but true ask me how I know!
If you search around for 3L build postings, most will end up spending 10-15K for a good, reliable build. If you really search around for good deals on parts you can save a couple of grand but ended up taking a year + for the project to complete.
There is really no short cut when it comes to building these engine right.
If you search around for 3L build postings, most will end up spending 10-15K for a good, reliable build. If you really search around for good deals on parts you can save a couple of grand but ended up taking a year + for the project to complete.
There is really no short cut when it comes to building these engine right.
04-13-2010, 04:25 PM
#10
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Blue printing and balance all reciprocating part- forgot about that 
Lots of downtime to send the parts away to have them polished to make them shiny!
Lots of downtime to send the parts away to have them polished to make them shiny!
04-13-2010, 07:43 PM
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Yes, I realise that a 951 crank has a different stroke... that was my point! Wouldn't using a 951 crank result in a lower CR?
Apart from the engine internals, I'd do the work myself (and if the engine work was not too specialised, I'd consider doing that as well).
04-13-2010, 07:48 PM
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BTW, I should have been clear that I wasn't thinking of turboing a 3.0L to get to very high HP numbers, but rather to have a car that had the benefits of a 951 in the upper RPM range but without the 8V/2.5L/low compression lag at the bottom (which I think is a drag for street driving, whereas I like the S2 a lot). So basic idea is sort of S2 at bottom, 951 at the top. Modest hp increase (say about a 300hp target at the crank), relatively low boost. (At least for stage 1.) Entry level 3.0 turbo, if you will.
Why not supercharge instead? Several reasons. Supercharging options I've considered (so far) all involve trade-offs or compromises that I'm not happy with. Actually, thinking about supercharging is what got me thinking (in principle) about the 3.0L turbo options.
So, back to the detail. What's a 2.7L head with a set of 951 exhaust valves going to cost?
Why not supercharge instead? Several reasons. Supercharging options I've considered (so far) all involve trade-offs or compromises that I'm not happy with. Actually, thinking about supercharging is what got me thinking (in principle) about the 3.0L turbo options.
So, back to the detail. What's a 2.7L head with a set of 951 exhaust valves going to cost?
04-13-2010, 07:49 PM
#14
Yes, but it would also drop displacement. A 2.5 crank in a 3L block is 2.7 I think. That's how they made the 2.7s. A thicker headgasket is really more of a band-aid fix rather than a proper solution IMO.
Figure 7-900 for a good 2.7 head. Their prices have dropped since I bought mine
I bought new valve springs for about $100, and had a friend hook me up with a good set of valves.
Also you may find it cheaper to use a 2.5 head and modify the front water neck to work with a 3L block. The mod is probably about $300.
Figure 7-900 for a good 2.7 head. Their prices have dropped since I bought mine
I bought new valve springs for about $100, and had a friend hook me up with a good set of valves.Also you may find it cheaper to use a 2.5 head and modify the front water neck to work with a 3L block. The mod is probably about $300.
04-13-2010, 08:02 PM
#15
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How much can you lower compression with a very thick cometic headgasket?
Yes, I realise that a 951 crank has a different stroke... that was my point! Wouldn't using a 951 crank result in a lower CR?
Apart from the engine internals, I'd do the work myself (and if the engine work was not too specialised, I'd consider doing that as well).
Yes, I realise that a 951 crank has a different stroke... that was my point! Wouldn't using a 951 crank result in a lower CR?
Apart from the engine internals, I'd do the work myself (and if the engine work was not too specialised, I'd consider doing that as well).
You need to search. This has been discussed SOOO MANY TIMES that it has become comical.
There are NO SHORTCUTS.