I've been buying parts and such for a rebuild at the end of next year. What I'm wondering is what is a good HP number to shoot for. This will be an everyday car. Also since I will be using this everyday I don't want the CR to be to low. What do you guys think the best compromise is for CR vs Boost. BTW I will be running either the GT35R or the GT35/40R.

 

With either of those superb GT Series turbo's you would get 580 - 620 BHP.

As for CR.....can of worms really..........some very well respected tuners on here would only do a conversion like that on 7.2:1.............

While others (Simon @ Norris Designs for example) would go the high CR route - i.e. almost standard CR...........As (*we think) he's done with Nick's engine (Bristol Group) that is fitted with the GT35/40R.

* Secret CR on this engine AFAIK

============================================

 

I've heard mentioned a few times 7.9:1 What do you all think about that?

 

i use mine everyday and am running a low comp 7.2-1 engine and off boost it drives like a normal 2.0 sierra, however, once its on cam and boost its just soooooooo much fun on the road

It depends what you want it to do???

A) a traffic light grand prix champion
b)a motorway missile


but remember no matter what you do to them, when you start driving them like you stole them, they drink fuel like nobodies business, i get about 20mpg if i am nurse maiding it and about 12-14mpg when she's tearing the tarmac a new asshole


Pugo

 

I don't care about fuel milage to much. Since I'm in the US military we get special prices on fuel. Since it was brought up what are some good cam choices that keep lag at a minimum. I know that using a GT will help but I would like the boost to come on as soon as possible for off the line. No NOS

 

IMO comp ratio affects how powerful it is off boost, but not hugely how soon the boost comes in, a bit, but not as much as other factors.

If you want big power n little lag then low comp n big boost with clever cam/head specs is a better bet i reckon. dont have to go hugely low anyhow if you wanting about 600bhp, Rod running 7.2:1 i think.

What fuel can u get cheap? If its high octane then you can get away with higher comp too.

Also beware of people claiming they running high comp when infact they bullshitting to sound good

 

Steve, I nearly agree with everthing you say here

BUT

I have been involved with many tuners that run HI comp Big power cars,
all makes including Fords and Jap and they do exist and are mostly
reliable in this form.

You are right that there are lots of bull shiters but thats life.

This is mainly due to "MODERN" piston crown profile design.

Cant quote many examples due to "secrecy" that I have promised to maintain.

Some examples ...

1) My car is 437 bhp and runs 7.8:1 CR.
2) A standard EVO is 9:1 and I THINK is good for 380 ish bhp without CR change.
3) One of the 600bhp engines I have been involved with has a CR in excess of 8:1
(EGT's on this are well within limits !)

 

The highest we can buy is 98 but I can get octane boost whenever I need. So what we're looking at so far is 7.2:1 CR, GT35/40R, Autronic ECU, and still looking into what cams to use. I've hear a lot of people use BD10 intake and stock exhaust? does that sound right?

 

you could go higher cr nearer standard even would not waste time with bd 10 go for bd14 at least pistons need to be pocketed though. head ported to 25 mm lag then kept to minimum

 

I'll be going with custom pistons. When you say head ported to 25mm your talking about runners or valves?

 

Si- I think i know what you mean about the pistons, combustion chamber shape too...



But its like the Head/Cam specs, i didnt wanna go into details...

 

Itsmeagain,

 

That is nice!!!!!!!!! Well lets talk fuel systems. I know that there has been talk about the Esccos having a bad designed tank and when it get a little low it might stumble from feul slosh. Does someone make a replacement tank or have a better system?

 

BTTT

 

Porkie on here has a really nice alloy tank - talk to him. He did put up some pictures

 

I was thinking of taking my tank out and having one fabricated to go in it's place. That way i could put the sump where I needed it an duse bigger pumps.

 

For every dayuse i would use a gt28 or grp a t3/4 with a cr of 7.6-1.Then theres the head,cams ect......

 

I've been seeing a lot of talk here lately about spec so how does this sound. 200 block, standard crank and rods, high volume oil pump, 7.9:1 pistons, Cometic head gasket with standard head bolts, late Esccos intake and exhaust manifolds, 4wd head with standard valves 3 angle valve job with ported and polished bowls, bd14 intake cam and standard exhaust cam, variable cam gears, the full Pro Alloy radiator, charge cooler and I/C kit, Greddy boost controller, MSD DIS-2 ignition, and Autronic SM2 managment??

 

what turbo?

 

GT35/40R

 

You wont get a GT35R on a 4wd manifold, Autronic CDI has been tested and found better than the MSD unit.

Mark

 

Well I'll have to look into the ignition then. I've been talking to a firm here and they tell me they can get the bigger flange on my manifold.

 

You will have better results with 2wd, I would not run a 4wd unit past 480hp.

Mark

 

I have a 2wd unit I'll probably just use it